WIP: A check

While here, add a new Matcher that determines whether a class is annotated with lombok's @Data.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -42,9 +42,9 @@ Please replace this sentence with log output, if applicable.
 <!-- Please complete the following information: -->
 
 - Operating system (e.g. MacOS Monterey).
-- Java version (i.e. `java --version`, e.g. `17.0.3`).
-- Error Prone version (e.g. `2.15.0`).
-- Error Prone Support version (e.g. `0.3.0`).
+- Java version (i.e. `java --version`, e.g. `17.0.7`).
+- Error Prone version (e.g. `2.18.0`).
+- Error Prone Support version (e.g. `0.9.0`).
 
 ### Additional context
 

.github/workflows/build.yaml

@@ -10,34 +10,32 @@ jobs:
     strategy:
       matrix:
         os: [ ubuntu-22.04 ]
-        jdk: [ 11.0.16, 17.0.4, 19 ]
+        jdk: [ 11.0.19, 17.0.7, 20.0.1 ]
         distribution: [ temurin ]
         experimental: [ false ]
         include:
           - os: macos-12
-            jdk: 17.0.4
+            jdk: 17.0.7
             distribution: temurin
             experimental: false
           - os: windows-2022
-            jdk: 17.0.4
+            jdk: 17.0.7
             distribution: temurin
             experimental: false
-          - os: ubuntu-22.04
-            jdk: 20-ea
-            distribution: zulu
-            experimental: true
     runs-on: ${{ matrix.os }}
     continue-on-error: ${{ matrix.experimental }}
     steps:
-        # We run the build twice for each supported JDK: once against the
-        # original Error Prone release, using only Error Prone checks available
-        # on Maven Central, and once against the Picnic Error Prone fork,
-        # additionally enabling all checks defined in this project and any
-        # Error Prone checks available only from other artifact repositories.
+      # We run the build twice for each supported JDK: once against the
+      # original Error Prone release, using only Error Prone checks available
+      # on Maven Central, and once against the Picnic Error Prone fork,
+      # additionally enabling all checks defined in this project and any Error
+      # Prone checks available only from other artifact repositories.
       - name: Check out code
-        uses: actions/checkout@v3.1.0
+        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+        with:
+          persist-credentials: false
       - name: Set up JDK
-        uses: actions/setup-java@v3.8.0
+        uses: actions/setup-java@cd89f46ac9d01407894225f350157564c9c7cee2 # v3.12.0
         with:
           java-version: ${{ matrix.jdk }}
           distribution: ${{ matrix.distribution }}
@@ -52,4 +50,3 @@ jobs:
         run: mvn build-helper:remove-project-artifact
 
 # XXX: Enable Codecov once we "go public".
-# XXX: Enable SonarCloud once we "go public".

.github/workflows/codeql.yml

@@ -0,0 +1,44 @@
+# Analyzes the code using GitHub's default CodeQL query database.
+# Identified issues are registered with GitHub's code scanning dashboard. When
+# a pull request is analyzed, any offending lines are annotated. See
+# https://codeql.github.com for details.
+name: CodeQL analysis
+on:
+  pull_request:
+  push:
+    branches: [ master ]
+  schedule:
+    - cron: '0 4 * * 1'
+permissions:
+  contents: read
+jobs:
+  analyze:
+    strategy:
+      matrix:
+        language: [ java, ruby ]
+    permissions:
+      contents: read
+      security-events: write
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Check out code
+        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+        with:
+          persist-credentials: false
+      - name: Set up JDK
+        uses: actions/setup-java@cd89f46ac9d01407894225f350157564c9c7cee2 # v3.12.0
+        with:
+          java-version: 17.0.7
+          distribution: temurin
+          cache: maven
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@a09933a12a80f87b87005513f0abb1494c27a716 # v2.21.4
+        with:
+          languages: ${{ matrix.language }}
+      - name: Perform minimal build
+        if: matrix.language == 'java'
+        run: mvn -T1C clean install -DskipTests -Dverification.skip
+      - name: Perform CodeQL analysis
+        uses: github/codeql-action/analyze@a09933a12a80f87b87005513f0abb1494c27a716 # v2.21.4
+        with:
+          category: /language:${{ matrix.language }}

.github/workflows/deploy-website.yaml

@@ -3,22 +3,24 @@ on:
   pull_request:
   push:
     branches: [ master, website ]
+permissions:
+  contents: read
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
 jobs:
   build:
-    permissions:
-      contents: read
     runs-on: ubuntu-22.04
     steps:
       - name: Check out code
-        uses: actions/checkout@v3.1.0
-      - uses: ruby/setup-ruby@v1.126.0
+        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+        with:
+          persist-credentials: false
+      - uses: ruby/setup-ruby@250fcd6a742febb1123a77a841497ccaa8b9e939 # v1.152.0
         with:
           working-directory: ./website
           bundler-cache: true
       - name: Configure Github Pages
-        uses: actions/configure-pages@v2.1.3
+        uses: actions/configure-pages@f156874f8191504dae5b037505266ed5dda6c382 # v3.0.6
       - name: Generate documentation
         run: ./generate-docs.sh
       - name: Build website with Jekyll
@@ -30,7 +32,7 @@ jobs:
         # "Refaster rules" terminology on our website and in the code.
         run: bundle exec htmlproofer --disable_external true --check-external-hash false ./_site
       - name: Upload website as artifact
-        uses: actions/upload-pages-artifact@v1.0.5
+        uses: actions/upload-pages-artifact@a753861a5debcf57bf8b404356158c8e1e33150c # v2.0.0
         with:
           path: ./website/_site
   deploy:
@@ -46,4 +48,4 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v1.2.3
+        uses: actions/deploy-pages@9dbe3824824f8a1377b8e298bafde1a50ede43e5 # v2.0.4

.github/workflows/openssf-scorecard.yml

@@ -0,0 +1,36 @@
+# Analyzes the code base and GitHub project configuration for adherence to
+# security best practices for open source software. Identified issues are
+# registered with GitHub's code scanning dashboard. When a pull request is
+# analyzed, any offending lines are annotated. See
+# https://securityscorecards.dev for details.
+name: OpenSSF Scorecard update
+on:
+  pull_request:
+  push:
+    branches: [ master ]
+  schedule:
+    - cron: '0 4 * * 1'
+permissions:
+  contents: read
+jobs:
+  analyze:
+    permissions:
+      contents: read
+      security-events: write
+      id-token: write
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Check out code
+        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+        with:
+          persist-credentials: false
+      - name: Run OpenSSF Scorecard analysis
+        uses: ossf/scorecard-action@08b4669551908b1024bb425080c797723083c031 # v2.2.0
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          publish_results: ${{ github.ref == 'refs/heads/master' }}
+      - name: Update GitHub's code scanning dashboard
+        uses: github/codeql-action/upload-sarif@a09933a12a80f87b87005513f0abb1494c27a716 # v2.21.4
+        with:
+          sarif_file: results.sarif

.github/workflows/pitest-analyze-pr.yml

@@ -12,13 +12,14 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - name: Check out code
-        uses: actions/checkout@v3.1.0
+        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
         with:
           fetch-depth: 2
+          persist-credentials: false
       - name: Set up JDK
-        uses: actions/setup-java@v3.8.0
+        uses: actions/setup-java@cd89f46ac9d01407894225f350157564c9c7cee2 # v3.12.0
         with:
-          java-version: 17.0.4
+          java-version: 17.0.7
           distribution: temurin
           cache: maven
       - name: Run Pitest
@@ -31,7 +32,7 @@ jobs:
       - name: Aggregate Pitest reports
         run: mvn pitest-git:aggregate -DkilledEmoji=":tada:" -DmutantEmoji=":zombie:" -DtrailingText="Mutation testing report by [Pitest](https://pitest.org/). Review any surviving mutants by inspecting the line comments under [_Files changed_](${{ github.event.number }}/files)."
       - name: Upload Pitest reports as artifact
-        uses: actions/upload-artifact@v3.1.1
+        uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
         with:
           name: pitest-reports
           path: ./target/pit-reports-ci

.github/workflows/pitest-update-pr.yml

@@ -9,24 +9,28 @@ on:
       - completed
 permissions:
   actions: read
-  checks: write
-  contents: read
-  pull-requests: write
 jobs:
   update-pr:
     if: ${{ github.event.workflow_run.conclusion == 'success' }}
+    permissions:
+      actions: read
+      checks: write
+      contents: read
+      pull-requests: write
     runs-on: ubuntu-22.04
     steps:
       - name: Check out code
-        uses: actions/checkout@v3.1.0
-      - name: Set up JDK
-        uses: actions/setup-java@v3.8.0
+        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
         with:
-          java-version: 17.0.4
+          persist-credentials: false
+      - name: Set up JDK
+        uses: actions/setup-java@cd89f46ac9d01407894225f350157564c9c7cee2 # v3.12.0
+        with:
+          java-version: 17.0.7
           distribution: temurin
           cache: maven
       - name: Download Pitest analysis artifact
-        uses: dawidd6/action-download-artifact@v2.24.2
+        uses: dawidd6/action-download-artifact@246dbf436b23d7c49e21a7ab8204ca9ecd1fe615 # v2.27.0
         with:
           workflow: ${{ github.event.workflow_run.workflow_id }}
           name: pitest-reports

.github/workflows/sonarcloud.yml

@@ -0,0 +1,36 @@
+# Analyzes the code base using SonarCloud. See
+# https://sonarcloud.io/project/overview?id=PicnicSupermarket_error-prone-support.
+name: SonarCloud analysis
+on:
+  pull_request:
+  push:
+    branches: [ master ]
+  schedule:
+    - cron: '0 4 * * 1'
+permissions:
+  contents: read
+jobs:
+  analyze:
+    permissions:
+      contents: read
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Check out code
+        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+        with:
+          fetch-depth: 0
+          persist-credentials: false
+      - name: Set up JDK
+        uses: actions/setup-java@cd89f46ac9d01407894225f350157564c9c7cee2 # v3.12.0
+        with:
+          java-version: 17.0.7
+          distribution: temurin
+          cache: maven
+      - name: Create missing `test` directory
+        # XXX: Drop this step in favour of actually having a test.
+        run: mkdir refaster-compiler/src/test
+      - name: Perform SonarCloud analysis
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
+        run: mvn -T1C jacoco:prepare-agent verify jacoco:report sonar:sonar -Dverification.skip -Dsonar.projectKey=PicnicSupermarket_error-prone-support

.renovaterc.json

@@ -1,5 +1,8 @@
 {
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": [
+    "helpers:pinGitHubActionDigests"
+  ],
   "packageRules": [
     {
       "matchPackagePatterns": [
@@ -9,10 +12,11 @@
       "separateMinorPatch": true
     },
     {
-      "matchPackagePatterns": [
-        "^ruby\\/setup-ruby$"
+      "matchDepNames": [
+        "github/codeql-action",
+        "ruby/setup-ruby"
       ],
-      "schedule": "* * 1 * *"
+      "schedule": "every 4 weeks on Monday"
     }
   ],
   "reviewers": [

CONTRIBUTING.md

@@ -48,6 +48,17 @@ be accepted. When in doubt, make sure to first raise an
 
 To the extent possible, the pull request process guards our coding guidelines.
 Some pointers:
+- Try to make sure that the
+  [`./run-full-build.sh`][error-prone-support-full-build] script completes
+  successfully, ideally before opening a pull request. See the [development
+  instructions][error-prone-support-developing] for details on how to
+  efficiently resolve many of the errors and warnings that may be reported. (In
+  particular, make sure to run `mvn fmt:format` and
+  [`./apply-error-prone-suggestions.sh`][error-prone-support-patch].) That
+  said, if you feel that the build fails for invalid or debatable reasons, or
+  if you're unsure how to best resolve an issue, don't let that discourage you
+  from opening a PR with a failing build; we can have a look at the issue
+  together!
 - Checks should be _topical_: ideally they address a single concern.
 - Where possible checks should provide _fixes_, and ideally these are
   completely behavior-preserving. In order for a check to be adopted by users
@@ -66,6 +77,9 @@ Some pointers:
   sneak in unrelated changes; instead just open more than one pull request 😉.
 
 [error-prone-criteria]: https://errorprone.info/docs/criteria
+[error-prone-support-developing]: https://github.com/PicnicSupermarket/error-prone-support/tree/master#-developing-error-prone-support
+[error-prone-support-full-build]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/run-full-build.sh
 [error-prone-support-issues]: https://github.com/PicnicSupermarket/error-prone-support/issues
-[error-prone-support-mutation-tests]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/run-mutation-tests.sh
+[error-prone-support-mutation-tests]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/run-branch-mutation-tests.sh
+[error-prone-support-patch]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/apply-error-prone-suggestions.sh
 [error-prone-support-pulls]: https://github.com/PicnicSupermarket/error-prone-support/pulls

README.md

@@ -21,7 +21,18 @@ code_][picnic-blog-ep-post].
 
 [![Maven Central][maven-central-badge]][maven-central-search]
 [![Reproducible Builds][reproducible-builds-badge]][reproducible-builds-report]
+[![OpenSSF Best Practices][openssf-best-practices-badge]][openssf-best-practices-checklist]
+[![OpenSSF Scorecard][openssf-scorecard-badge]][openssf-scorecard-report]
+[![CodeQL Analysis][codeql-badge]][codeql-master]
 [![GitHub Actions][github-actions-build-badge]][github-actions-build-master]
+[![Mutation tested with PIT][pitest-badge]][pitest]
+[![Quality Gate Status][sonarcloud-quality-badge]][sonarcloud-quality-master]
+[![Maintainability Rating][sonarcloud-maintainability-badge]][sonarcloud-maintainability-master]
+[![Reliability Rating][sonarcloud-reliability-badge]][sonarcloud-reliability-master]
+[![Security Rating][sonarcloud-security-badge]][sonarcloud-security-master]
+[![Coverage][sonarcloud-coverage-badge]][sonarcloud-coverage-master]
+[![Duplicated Lines (%)][sonarcloud-duplication-badge]][sonarcloud-duplication-master]
+[![Technical Debt][sonarcloud-technical-debt-badge]][sonarcloud-technical-debt-master]
 [![License][license-badge]][license]
 [![PRs Welcome][pr-badge]][contributing]
 
@@ -98,8 +109,9 @@ definition. -->
 
 #### Gradle
 
-1. First, follow the [installation guide]
-   [error-prone-gradle-installation-guide] of the `gradle-errorprone-plugin`.
+1. First, follow the [installation
+   guide][error-prone-gradle-installation-guide] of the
+   `gradle-errorprone-plugin`.
 2. Next, edit your `build.gradle` file to add one or more Error Prone Support
    modules:
 
@@ -171,8 +183,15 @@ rules][refaster-rules].
 ## 👷 Developing Error Prone Support
 
 This is a [Maven][maven] project, so running `mvn clean install` performs a
-full clean build and installs the library to your local Maven repository. Some
-relevant flags:
+full clean build and installs the library to your local Maven repository.
+
+Once you've made changes, the build may fail due to a warning or error emitted
+by static code analysis. The flags and commands listed below allow you to
+suppress or (in a large subset of cases) automatically fix such cases. Make
+sure to carefully check the available options, as this can save you significant
+amounts of development time!
+
+Relevant Maven build parameters:
 
 - `-Dverification.warn` makes the warnings and errors emitted by various
   plugins and the Java compiler non-fatal, where possible.
@@ -189,19 +208,28 @@ relevant flags:
   Pending a release of [google/error-prone#3301][error-prone-pull-3301], this
   flag must currently be used in combination with `-Perror-prone-fork`.
 
-Some other commands one may find relevant:
+Other highly relevant commands:
 
 - `mvn fmt:format` formats the code using
   [`google-java-format`][google-java-format].
-- `./run-mutation-tests.sh` runs mutation tests using [Pitest][pitest]. The
-  results can be reviewed by opening the respective
-  `target/pit-reports/index.html` files. For more information check the [PIT
-  Maven plugin][pitest-maven].
-- `./apply-error-prone-suggestions.sh` applies Error Prone and Error Prone
-  Support code suggestions to this project. Before running this command, make
-  sure to have installed the project (`mvn clean install`) and make sure that
-  the current working directory does not contain unstaged or uncommited
-  changes.
+- [`./run-full-build.sh`][script-run-full-build] builds the project twice,
+  where the second pass validates compatbility with Picnic's [Error Prone
+  fork][error-prone-fork-repo] and compliance of the code with any rules
+  defined within this project. (Consider running this before [opening a pull
+  request][contributing-pull-request], as the PR checks also perform this
+  validation.)
+- [`./apply-error-prone-suggestions.sh`][script-apply-error-prone-suggestions]
+  applies Error Prone and Error Prone Support code suggestions to this project.
+  Before running this command, make sure to have installed the project (`mvn
+  clean install`) and make sure that the current working directory does not
+  contain unstaged or uncommited changes.
+- [`./run-branch-mutation-tests.sh`][script-run-branch-mutation-tests] uses
+  [Pitest][pitest] to run mutation tests against code that is modified relative
+  to the upstream default branch. The results can be reviewed by opening the
+  respective `target/pit-reports/index.html` files. One can use
+  [`./run-mutation-tests.sh`][script-run-mutation-tests] to run mutation tests
+  against _all_ code in the current working directory. For more information
+  check the [PIT Maven plugin][pitest-maven].
 
 When running the project's tests in IntelliJ IDEA, you might see the following
 error:
@@ -228,9 +256,17 @@ Want to report or fix a bug, suggest or add a new feature, or improve the
 documentation? That's awesome! Please read our [contribution
 guidelines][contributing].
 
+### Security
+
+If you want to report a security vulnerability, please do so through a private
+channel; please see our [security policy][security] for details.
+
 [bug-checks]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/
 [bug-checks-identity-conversion]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/IdentityConversion.java
+[codeql-badge]: https://github.com/PicnicSupermarket/error-prone-support/actions/workflows/codeql.yml/badge.svg?branch=master&event=push
+[codeql-master]: https://github.com/PicnicSupermarket/error-prone-support/actions/workflows/codeql.yml?query=branch:master+event:push
 [contributing]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/CONTRIBUTING.md
+[contributing-pull-request]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/CONTRIBUTING.md#-opening-a-pull-request
 [error-prone-bugchecker]: https://github.com/google/error-prone/blob/master/check_api/src/main/java/com/google/errorprone/bugpatterns/BugChecker.java
 [error-prone-fork-jitpack]: https://jitpack.io/#PicnicSupermarket/error-prone
 [error-prone-fork-repo]: https://github.com/PicnicSupermarket/error-prone
@@ -239,7 +275,7 @@ guidelines][contributing].
 [error-prone-orig-repo]: https://github.com/google/error-prone
 [error-prone-pull-3301]: https://github.com/google/error-prone/pull/3301
 [github-actions-build-badge]: https://github.com/PicnicSupermarket/error-prone-support/actions/workflows/build.yaml/badge.svg
-[github-actions-build-master]: https://github.com/PicnicSupermarket/error-prone-support/actions/workflows/build.yaml?query=branch%3Amaster
+[github-actions-build-master]: https://github.com/PicnicSupermarket/error-prone-support/actions/workflows/build.yaml?query=branch:master&event=push
 [google-java-format]: https://github.com/google/google-java-format
 [idea-288052]: https://youtrack.jetbrains.com/issue/IDEA-288052
 [license-badge]: https://img.shields.io/github/license/PicnicSupermarket/error-prone-support
@@ -247,8 +283,13 @@ guidelines][contributing].
 [maven-central-badge]: https://img.shields.io/maven-central/v/tech.picnic.error-prone-support/error-prone-support?color=blue
 [maven-central-search]: https://search.maven.org/artifact/tech.picnic.error-prone-support/error-prone-support
 [maven]: https://maven.apache.org
-[picnic-blog]: https://blog.picnic.nl
+[openssf-best-practices-badge]: https://bestpractices.coreinfrastructure.org/projects/7199/badge
+[openssf-best-practices-checklist]: https://bestpractices.coreinfrastructure.org/projects/7199
+[openssf-scorecard-badge]: https://img.shields.io/ossf-scorecard/github.com/PicnicSupermarket/error-prone-support?label=openssf%20scorecard
+[openssf-scorecard-report]: https://securityscorecards.dev/viewer/?uri=github.com/PicnicSupermarket/error-prone-support
 [picnic-blog-ep-post]: https://blog.picnic.nl/picnic-loves-error-prone-producing-high-quality-and-consistent-java-code-b8a566be6886
+[picnic-blog]: https://blog.picnic.nl
+[pitest-badge]: https://img.shields.io/badge/-Mutation%20tested%20with%20PIT-blue.svg
 [pitest]: https://pitest.org
 [pitest-maven]: https://pitest.org/quickstart/maven
 [pr-badge]: https://img.shields.io/badge/PRs-welcome-brightgreen.svg
@@ -257,3 +298,22 @@ guidelines][contributing].
 [refaster-rules]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/
 [reproducible-builds-badge]: https://img.shields.io/badge/Reproducible_Builds-ok-success?labelColor=1e5b96
 [reproducible-builds-report]: https://github.com/jvm-repo-rebuild/reproducible-central/blob/master/content/tech/picnic/error-prone-support/error-prone-support/README.md
+[script-apply-error-prone-suggestions]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/apply-error-prone-suggestions.sh
+[script-run-branch-mutation-tests]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/run-branch-mutation-tests.sh
+[script-run-full-build]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/run-full-build.sh
+[script-run-mutation-tests]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/run-mutation-tests.sh
+[security]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/SECURITY.md
+[sonarcloud-coverage-badge]: https://sonarcloud.io/api/project_badges/measure?project=PicnicSupermarket_error-prone-support&metric=coverage
+[sonarcloud-coverage-master]: https://sonarcloud.io/component_measures?id=PicnicSupermarket_error-prone-support&metric=coverage
+[sonarcloud-duplication-badge]: https://sonarcloud.io/api/project_badges/measure?project=PicnicSupermarket_error-prone-support&metric=duplicated_lines_density
+[sonarcloud-duplication-master]: https://sonarcloud.io/component_measures?id=PicnicSupermarket_error-prone-support&metric=duplicated_lines_density
+[sonarcloud-maintainability-badge]: https://sonarcloud.io/api/project_badges/measure?project=PicnicSupermarket_error-prone-support&metric=sqale_rating
+[sonarcloud-maintainability-master]: https://sonarcloud.io/component_measures?id=PicnicSupermarket_error-prone-support&metric=sqale_rating
+[sonarcloud-quality-badge]: https://sonarcloud.io/api/project_badges/measure?project=PicnicSupermarket_error-prone-support&metric=alert_status
+[sonarcloud-quality-master]: https://sonarcloud.io/summary/new_code?id=PicnicSupermarket_error-prone-support
+[sonarcloud-reliability-badge]: https://sonarcloud.io/api/project_badges/measure?project=PicnicSupermarket_error-prone-support&metric=reliability_rating
+[sonarcloud-reliability-master]: https://sonarcloud.io/component_measures?id=PicnicSupermarket_error-prone-support&metric=reliability_rating
+[sonarcloud-security-badge]: https://sonarcloud.io/api/project_badges/measure?project=PicnicSupermarket_error-prone-support&metric=security_rating
+[sonarcloud-security-master]: https://sonarcloud.io/component_measures?id=PicnicSupermarket_error-prone-support&metric=security_rating
+[sonarcloud-technical-debt-badge]: https://sonarcloud.io/api/project_badges/measure?project=PicnicSupermarket_error-prone-support&metric=sqale_index
+[sonarcloud-technical-debt-master]: https://sonarcloud.io/component_measures?id=PicnicSupermarket_error-prone-support&metric=sqale_index

SECURITY.md

@@ -0,0 +1,23 @@
+# Security policy
+
+We take security seriously. We are mindful of Error Prone Support's place in
+the software supply chain, and the risks and responsibilities that come with
+this.
+
+## Supported versions
+
+This project uses [semantic versioning][semantic-versioning]. In general, only
+the latest version of this software is supported. That said, if users have a
+compelling reason to ask for patch release of an older major release, then we
+will seriously consider such a request. We do urge users to stay up-to-date and
+use the latest release where feasible.
+
+## Reporting a vulnerability
+
+To report a vulnerability, please visit the [security
+advisories][security-advisories] page and click _Report a vulnerability_. We
+will take such reports seriously and work with you to resolve the issue in a
+timely manner.
+
+[security-advisories]: https://github.com/PicnicSupermarket/error-prone-support/security/advisories
+[semantic-versioning]: https://semver.org

documentation-support/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.8.1-SNAPSHOT</version>
+        <version>0.13.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>documentation-support</artifactId>
@@ -83,5 +83,10 @@
             <artifactId>junit-jupiter-params</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <scope>provided</scope>
+        </dependency>
     </dependencies>
 </project>

documentation-support/src/main/java/tech/picnic/errorprone/documentation/ExtractorType.java

@@ -25,6 +25,7 @@ enum ExtractorType {
     return identifier;
   }
 
+  @SuppressWarnings("java:S1452" /* The extractor returns data of an unspecified type. */)
   Extractor<?> getExtractor() {
     return extractor;
   }

documentation-support/src/main/java/tech/picnic/errorprone/documentation/LombokCanary.java.decide-what-to-do-with-this

@@ -0,0 +1,13 @@
+package tech.picnic.errorprone.documentation;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import lombok.Data;
+import org.jspecify.annotations.Nullable;
+
+// XXX: Rename all this stuff.
+@Data
+@SuppressWarnings("EqualsMissingNullable") // XXX: Drop after EP upgrade.
+final class LombokCanary {
+  @JsonProperty("custom_field_name")
+  private @Nullable String field;
+}

documentation-support/src/test/java/tech/picnic/errorprone/documentation/BugPatternExtractorTest.java

@@ -14,7 +14,6 @@ import com.google.errorprone.bugpatterns.BugChecker.ClassTreeMatcher;
 import com.google.errorprone.matchers.Description;
 import com.sun.source.tree.ClassTree;
 import java.io.IOException;
-import java.nio.file.Files;
 import java.nio.file.Path;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
@@ -120,7 +119,8 @@ final class BugPatternExtractorTest {
 
   private static void verifyFileMatchesResource(
       Path outputDirectory, String fileName, String resourceName) throws IOException {
-    assertThat(Files.readString(outputDirectory.resolve(fileName)))
+    assertThat(outputDirectory.resolve(fileName))
+        .content(UTF_8)
         .isEqualToIgnoringWhitespace(getResource(resourceName));
   }
 

documentation-support/src/test/java/tech/picnic/errorprone/documentation/DocumentationGeneratorTaskListenerTest.java

@@ -67,10 +67,11 @@ final class DocumentationGeneratorTaskListenerTest {
 
   @Test
   void excessArguments(@TempDir Path outputDirectory) {
+    String actualOutputDirectory = outputDirectory.toAbsolutePath() + " extra-arg";
     assertThatThrownBy(
             () ->
                 Compilation.compileWithDocumentationGenerator(
-                    outputDirectory.toAbsolutePath() + " extra-arg", "A.java", "package pkg;"))
+                    actualOutputDirectory, "A.java", "package pkg;"))
         .isInstanceOf(IllegalArgumentException.class)
         .hasMessage("Precisely one path must be provided");
   }

error-prone-contrib/README.md

@@ -24,7 +24,6 @@ project:
 
 - Document how to apply patches.
 - Document each of the checks.
-- Add [SonarQube][sonarcloud] and [Codecov][codecov] integrations.
 - Add non-Java file formatting support, like we have internally at Picnic.
   (I.e., somehow open-source that stuff.)
 - Auto-generate a website listing each of the checks, just like the Error Prone
@@ -273,7 +272,6 @@ Refaster's expressiveness:
 [autorefactor]: https://autorefactor.org
 [bettercodehub]: https://bettercodehub.com
 [checkstyle-external-project-tests]: https://github.com/checkstyle/checkstyle/blob/master/wercker.yml
-[codecov]: https://codecov.io
 [error-prone-bug-patterns]: https://errorprone.info/bugpatterns
 [error-prone]: https://errorprone.info
 [error-prone-repo]: https://github.com/google/error-prone
@@ -283,4 +281,3 @@ Refaster's expressiveness:
 [main-contributing]: ../CONTRIBUTING.md
 [main-readme]: ../README.md
 [modernizer-maven-plugin]: https://github.com/gaul/modernizer-maven-plugin
-[sonarcloud]: https://sonarcloud.io

error-prone-contrib/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.8.1-SNAPSHOT</version>
+        <version>0.13.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>error-prone-contrib</artifactId>
@@ -37,7 +37,7 @@
         <dependency>
             <groupId>${groupId.error-prone}</groupId>
             <artifactId>error_prone_test_helpers</artifactId>
-            <scope>test</scope>
+            <scope>provided</scope>
         </dependency>
         <dependency>
             <groupId>${project.groupId}</groupId>
@@ -126,6 +126,11 @@
             <artifactId>jakarta.servlet-api</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>javax.inject</groupId>
+            <artifactId>javax.inject</artifactId>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>javax.xml.bind</groupId>
             <artifactId>jaxb-api</artifactId>
@@ -171,6 +176,16 @@
             <artifactId>mockito-core</artifactId>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>org.mongodb</groupId>
+            <artifactId>mongodb-driver-core</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.reactivestreams</groupId>
             <artifactId>reactive-streams</artifactId>

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/AssociativeMethodInvocation.java

@@ -0,0 +1,103 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
+import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
+import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
+import static com.google.errorprone.matchers.Matchers.allOf;
+import static com.google.errorprone.matchers.Matchers.not;
+import static com.google.errorprone.matchers.Matchers.staticMethod;
+import static com.google.errorprone.matchers.Matchers.toType;
+import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+
+import com.google.auto.service.AutoService;
+import com.google.common.collect.ImmutableSet;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
+import com.google.errorprone.fixes.SuggestedFix;
+import com.google.errorprone.fixes.SuggestedFixes;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
+import com.google.errorprone.matchers.Matchers;
+import com.google.errorprone.refaster.Refaster;
+import com.google.errorprone.suppliers.Supplier;
+import com.google.errorprone.suppliers.Suppliers;
+import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.MethodInvocationTree;
+import com.sun.tools.javac.code.Type;
+import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+
+/**
+ * A {@link BugChecker} that flags unnecessarily nested usage of methods that implement an
+ * associative operation.
+ *
+ * <p>The arguments to such methods can be flattened without affecting semantics, while making the
+ * code more readable.
+ */
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary =
+        "This method implements an associative operation, so the list of operands can be flattened",
+    link = BUG_PATTERNS_BASE_URL + "AssociativeMethodInvocation",
+    linkType = CUSTOM,
+    severity = SUGGESTION,
+    tags = SIMPLIFICATION)
+public final class AssociativeMethodInvocation extends BugChecker
+    implements MethodInvocationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Supplier<Type> ITERABLE = Suppliers.typeFromClass(Iterable.class);
+  private static final ImmutableSet<Matcher<ExpressionTree>> ASSOCIATIVE_OPERATIONS =
+      ImmutableSet.of(
+          allOf(
+              staticMethod().onClass(Suppliers.typeFromClass(Matchers.class)).named("allOf"),
+              toType(MethodInvocationTree.class, not(hasArgumentOfType(ITERABLE)))),
+          allOf(
+              staticMethod().onClass(Suppliers.typeFromClass(Matchers.class)).named("anyOf"),
+              toType(MethodInvocationTree.class, not(hasArgumentOfType(ITERABLE)))),
+          staticMethod().onClass(Suppliers.typeFromClass(Refaster.class)).named("anyOf"));
+
+  /** Instantiates a new {@link AssociativeMethodInvocation} instance. */
+  public AssociativeMethodInvocation() {}
+
+  @Override
+  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+    if (tree.getArguments().isEmpty()) {
+      /* Absent any arguments, there is nothing to simplify. */
+      return Description.NO_MATCH;
+    }
+
+    for (Matcher<ExpressionTree> matcher : ASSOCIATIVE_OPERATIONS) {
+      if (matcher.matches(tree, state)) {
+        SuggestedFix fix = processMatchingArguments(tree, matcher, state);
+        return fix.isEmpty() ? Description.NO_MATCH : describeMatch(tree, fix);
+      }
+    }
+
+    return Description.NO_MATCH;
+  }
+
+  private static SuggestedFix processMatchingArguments(
+      MethodInvocationTree tree, Matcher<ExpressionTree> matcher, VisitorState state) {
+    SuggestedFix.Builder fix = SuggestedFix.builder();
+
+    for (ExpressionTree arg : tree.getArguments()) {
+      if (matcher.matches(arg, state)) {
+        MethodInvocationTree invocation = (MethodInvocationTree) arg;
+        fix.merge(
+            invocation.getArguments().isEmpty()
+                ? SuggestedFixes.removeElement(invocation, tree.getArguments(), state)
+                : SourceCode.unwrapMethodInvocation(invocation, state));
+      }
+    }
+
+    return fix.build();
+  }
+
+  private static Matcher<MethodInvocationTree> hasArgumentOfType(Supplier<Type> type) {
+    return (tree, state) ->
+        tree.getArguments().stream()
+            .anyMatch(arg -> ASTHelpers.isSubtype(ASTHelpers.getType(arg), type.get(state), state));
+  }
+}

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/AutowiredConstructor.java

@@ -58,8 +58,8 @@ public final class AutowiredConstructor extends BugChecker implements ClassTreeM
 
     /*
      * This is the only `@Autowired` constructor: suggest that it be removed. Note that this likely
-     * means that the associated import can be removed as well. Rather than adding code for this case we
-     * leave flagging the unused import to Error Prone's `RemoveUnusedImports` check.
+     * means that the associated import can be removed as well. Rather than adding code for this
+     * case we leave flagging the unused import to Error Prone's `RemoveUnusedImports` check.
      */
     AnnotationTree annotation = Iterables.getOnlyElement(annotations);
     return describeMatch(annotation, SourceCode.deleteWithTrailingWhitespace(annotation, state));

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/CanonicalAnnotationSyntax.java

@@ -51,6 +51,11 @@ public final class CanonicalAnnotationSyntax extends BugChecker implements Annot
 
   @Override
   public Description matchAnnotation(AnnotationTree tree, VisitorState state) {
+    //    if (!isSourceAccurateCodeAvailable(tree, state)) {
+    //      /* Without the source code there's not much we can do. */
+    //      return Description.NO_MATCH;
+    //    }
+
     return FIX_FACTORIES.stream()
         .map(op -> op.apply(tree, state))
         .flatMap(Optional::stream)
@@ -59,6 +64,14 @@ public final class CanonicalAnnotationSyntax extends BugChecker implements Annot
         .orElse(Description.NO_MATCH);
   }
 
+  // XXX: Explain, link to Lombok issue.
+  //  private static boolean isSourceAccurateCodeAvailable(AnnotationTree tree, VisitorState state)
+  // {
+  //    String source = state.getSourceForNode(tree);
+  //    String parentSource = state.getSourceForNode(state.getPath().getParentPath().getLeaf());
+  //    return source != null && parentSource != null && parentSource.contains(source);
+  //  }
+
   private static Optional<Fix> dropRedundantParentheses(AnnotationTree tree, VisitorState state) {
     if (!tree.getArguments().isEmpty()) {
       /* Parentheses are necessary. */
@@ -91,15 +104,15 @@ public final class CanonicalAnnotationSyntax extends BugChecker implements Annot
     ExpressionTree arg = args.get(0);
     if (state.getSourceForNode(arg) == null) {
       /*
-       * The annotation argument isn't doesn't have a source representation, e.g. because `value`
-       * isn't assigned to explicitly.
+       * The annotation argument doesn't have a source representation, e.g. because `value` isn't
+       * assigned explicitly.
        */
       return Optional.empty();
     }
 
     ExpressionTree expr = AnnotationMatcherUtils.getArgument(tree, "value");
-    if (expr == null) {
-      /* This is not an explicit assignment to the `value` attribute. */
+    if (expr == null || !SourceCode.isAccurateSourceLikelyAvailable(state)) {
+      /* This is (probably) not an explicit assignment to the `value` attribute. */
       return Optional.empty();
     }
 

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/CollectorMutability.java

@@ -30,7 +30,7 @@ import tech.picnic.errorprone.bugpatterns.util.ThirdPartyLibrary;
 @AutoService(BugChecker.class)
 @BugPattern(
     summary =
-        "Avoid `Collectors.to{List,Map,Set}` in favour of alternatives that emphasize (im)mutability",
+        "Avoid `Collectors.to{List,Map,Set}` in favor of collectors that emphasize (im)mutability",
     link = BUG_PATTERNS_BASE_URL + "CollectorMutability",
     linkType = CUSTOM,
     severity = WARNING,

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/DirectReturn.java

@@ -0,0 +1,175 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
+import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
+import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
+import static com.google.errorprone.matchers.Matchers.allOf;
+import static com.google.errorprone.matchers.Matchers.argument;
+import static com.google.errorprone.matchers.Matchers.isSameType;
+import static com.google.errorprone.matchers.Matchers.isVariable;
+import static com.google.errorprone.matchers.Matchers.not;
+import static com.google.errorprone.matchers.Matchers.returnStatement;
+import static com.google.errorprone.matchers.Matchers.staticMethod;
+import static com.google.errorprone.matchers.Matchers.toType;
+import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+
+import com.google.auto.service.AutoService;
+import com.google.common.collect.Streams;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.BlockTreeMatcher;
+import com.google.errorprone.fixes.SuggestedFix;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
+import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.AssignmentTree;
+import com.sun.source.tree.BlockTree;
+import com.sun.source.tree.ExpressionStatementTree;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.IdentifierTree;
+import com.sun.source.tree.MethodInvocationTree;
+import com.sun.source.tree.ReturnTree;
+import com.sun.source.tree.StatementTree;
+import com.sun.source.tree.Tree;
+import com.sun.source.tree.TryTree;
+import com.sun.source.tree.VariableTree;
+import com.sun.source.util.TreeScanner;
+import com.sun.tools.javac.code.Symbol;
+import java.util.List;
+import java.util.Optional;
+import org.jspecify.annotations.Nullable;
+import tech.picnic.errorprone.bugpatterns.util.MoreASTHelpers;
+import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+
+/**
+ * A {@link BugChecker} that flags unnecessary local variable assignments preceding a return
+ * statement.
+ */
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary = "Variable assignment is redundant; value can be returned directly",
+    link = BUG_PATTERNS_BASE_URL + "DirectReturn",
+    linkType = CUSTOM,
+    severity = SUGGESTION,
+    tags = SIMPLIFICATION)
+public final class DirectReturn extends BugChecker implements BlockTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Matcher<StatementTree> VARIABLE_RETURN = returnStatement(isVariable());
+  private static final Matcher<ExpressionTree> MOCKITO_MOCK_OR_SPY_WITH_IMPLICIT_TYPE =
+      allOf(
+          not(toType(MethodInvocationTree.class, argument(0, isSameType(Class.class.getName())))),
+          staticMethod().onClass("org.mockito.Mockito").namedAnyOf("mock", "spy"));
+
+  /** Instantiates a new {@link DirectReturn} instance. */
+  public DirectReturn() {}
+
+  @Override
+  public Description matchBlock(BlockTree tree, VisitorState state) {
+    List<? extends StatementTree> statements = tree.getStatements();
+    if (statements.size() < 2) {
+      return Description.NO_MATCH;
+    }
+
+    StatementTree finalStatement = statements.get(statements.size() - 1);
+    if (!VARIABLE_RETURN.matches(finalStatement, state)) {
+      return Description.NO_MATCH;
+    }
+
+    Symbol variableSymbol = ASTHelpers.getSymbol(((ReturnTree) finalStatement).getExpression());
+    StatementTree precedingStatement = statements.get(statements.size() - 2);
+
+    return tryMatchAssignment(variableSymbol, precedingStatement)
+        .filter(
+            resultExpr ->
+                canInlineToReturnStatement(resultExpr, state)
+                    && !isIdentifierSymbolReferencedInAssociatedFinallyBlock(variableSymbol, state))
+        .map(
+            resultExpr ->
+                describeMatch(
+                    precedingStatement,
+                    SuggestedFix.builder()
+                        .replace(
+                            precedingStatement,
+                            String.format("return %s;", SourceCode.treeToString(resultExpr, state)))
+                        .delete(finalStatement)
+                        .build()))
+        .orElse(Description.NO_MATCH);
+  }
+
+  private static Optional<ExpressionTree> tryMatchAssignment(Symbol targetSymbol, Tree tree) {
+    if (tree instanceof ExpressionStatementTree) {
+      return tryMatchAssignment(targetSymbol, ((ExpressionStatementTree) tree).getExpression());
+    }
+
+    if (tree instanceof AssignmentTree) {
+      AssignmentTree assignment = (AssignmentTree) tree;
+      return targetSymbol.equals(ASTHelpers.getSymbol(assignment.getVariable()))
+          ? Optional.of(assignment.getExpression())
+          : Optional.empty();
+    }
+
+    if (tree instanceof VariableTree) {
+      VariableTree declaration = (VariableTree) tree;
+      return declaration.getModifiers().getAnnotations().isEmpty()
+              && targetSymbol.equals(ASTHelpers.getSymbol(declaration))
+          ? Optional.ofNullable(declaration.getInitializer())
+          : Optional.empty();
+    }
+
+    return Optional.empty();
+  }
+
+  /**
+   * Tells whether inlining the given expression to the associated return statement can likely be
+   * done without changing the expression's return type.
+   *
+   * <p>Inlining an expression generally does not change its return type, but in rare cases the
+   * operation may have a functional impact. The sole case considered here is the inlining of a
+   * Mockito mock or spy construction without an explicit type. In such a case the type created
+   * depends on context, such as the method's return type.
+   */
+  private static boolean canInlineToReturnStatement(
+      ExpressionTree expressionTree, VisitorState state) {
+    return !MOCKITO_MOCK_OR_SPY_WITH_IMPLICIT_TYPE.matches(expressionTree, state)
+        || MoreASTHelpers.findMethodExitedOnReturn(state)
+            .filter(m -> MoreASTHelpers.areSameType(expressionTree, m.getReturnType(), state))
+            .isPresent();
+  }
+
+  /**
+   * Tells whether the given identifier {@link Symbol} is referenced in a {@code finally} block that
+   * is executed <em>after</em> control flow returns from the {@link VisitorState#getPath() current
+   * location}.
+   */
+  private static boolean isIdentifierSymbolReferencedInAssociatedFinallyBlock(
+      Symbol symbol, VisitorState state) {
+    return Streams.zip(
+            Streams.stream(state.getPath()).skip(1),
+            Streams.stream(state.getPath()),
+            (tree, child) -> {
+              if (!(tree instanceof TryTree)) {
+                return null;
+              }
+
+              BlockTree finallyBlock = ((TryTree) tree).getFinallyBlock();
+              return !child.equals(finallyBlock) ? finallyBlock : null;
+            })
+        .anyMatch(finallyBlock -> referencesIdentifierSymbol(symbol, finallyBlock));
+  }
+
+  private static boolean referencesIdentifierSymbol(Symbol symbol, @Nullable BlockTree tree) {
+    return Boolean.TRUE.equals(
+        new TreeScanner<Boolean, @Nullable Void>() {
+          @Override
+          public Boolean visitIdentifier(IdentifierTree node, @Nullable Void unused) {
+            return symbol.equals(ASTHelpers.getSymbol(node));
+          }
+
+          @Override
+          public Boolean reduce(Boolean r1, Boolean r2) {
+            return Boolean.TRUE.equals(r1) || Boolean.TRUE.equals(r2);
+          }
+        }.scan(tree, null));
+  }
+}

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/EmptyMethod.java

@@ -42,6 +42,7 @@ public final class EmptyMethod extends BugChecker implements MethodTreeMatcher {
   public EmptyMethod() {}
 
   @Override
+  @SuppressWarnings("java:S1067" /* Chaining disjunctions like this does not impact readability. */)
   public Description matchMethod(MethodTree tree, VisitorState state) {
     if (tree.getBody() == null
         || !tree.getBody().getStatements().isEmpty()

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/ErrorProneTestHelperSourceFormat.java

@@ -104,7 +104,9 @@ public final class ErrorProneTestHelperSourceFormat extends BugChecker
     String formatted;
     try {
       formatted = formatSourceCode(source, retainUnusedImports).trim();
-    } catch (FormatterException e) {
+    } catch (
+        @SuppressWarnings("java:S1166" /* Stack trace not relevant. */)
+        FormatterException e) {
       return buildDescription(methodInvocation)
           .setMessage(String.format("Source code is malformed: %s", e.getMessage()))
           .build();
@@ -131,7 +133,7 @@ public final class ErrorProneTestHelperSourceFormat extends BugChecker
         SuggestedFix.replace(
             startPos,
             endPos,
-            Splitter.on('\n')
+            Splitter.on(System.lineSeparator())
                 .splitToStream(formatted)
                 .map(state::getConstantExpression)
                 .collect(joining(", "))));
@@ -157,7 +159,7 @@ public final class ErrorProneTestHelperSourceFormat extends BugChecker
         return Optional.empty();
       }
 
-      source.append(value).append('\n');
+      source.append(value).append(System.lineSeparator());
     }
 
     return Optional.of(source.toString());

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/FluxFlatMapUsage.java

@@ -82,10 +82,8 @@ public final class FluxFlatMapUsage extends BugChecker
 
     SuggestedFix serializationFix = SuggestedFixes.renameMethodInvocation(tree, "concatMap", state);
     SuggestedFix concurrencyCapFix =
-        SuggestedFix.builder()
-            .postfixWith(
-                Iterables.getOnlyElement(tree.getArguments()), ", " + MAX_CONCURRENCY_ARG_NAME)
-            .build();
+        SuggestedFix.postfixWith(
+            Iterables.getOnlyElement(tree.getArguments()), ", " + MAX_CONCURRENCY_ARG_NAME);
 
     Description.Builder description = buildDescription(tree);
 

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/FluxImplicitBlock.java

@@ -0,0 +1,100 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.common.base.Preconditions.checkState;
+import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
+import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
+import static com.google.errorprone.BugPattern.StandardTags.CONCURRENCY;
+import static com.google.errorprone.BugPattern.StandardTags.PERFORMANCE;
+import static com.google.errorprone.matchers.method.MethodMatchers.instanceMethod;
+import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+
+import com.google.auto.service.AutoService;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
+import com.google.errorprone.fixes.SuggestedFix;
+import com.google.errorprone.fixes.SuggestedFixes;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
+import com.google.errorprone.suppliers.Supplier;
+import com.google.errorprone.suppliers.Suppliers;
+import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.MethodInvocationTree;
+import com.sun.tools.javac.code.Type;
+import com.sun.tools.javac.util.Position;
+import java.util.stream.Stream;
+import tech.picnic.errorprone.bugpatterns.util.ThirdPartyLibrary;
+
+/**
+ * A {@link BugChecker} that flags {@link reactor.core.publisher.Flux} operator usages that may
+ * implicitly cause the calling thread to be blocked.
+ *
+ * <p>Note that the methods flagged here are not themselves blocking, but iterating over the
+ * resulting {@link Iterable} or {@link Stream} may be.
+ */
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary = "Avoid iterating over `Flux`es in an implicitly blocking manner",
+    link = BUG_PATTERNS_BASE_URL + "FluxImplicitBlock",
+    linkType = CUSTOM,
+    severity = WARNING,
+    tags = {CONCURRENCY, PERFORMANCE})
+public final class FluxImplicitBlock extends BugChecker implements MethodInvocationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Matcher<ExpressionTree> FLUX_WITH_IMPLICIT_BLOCK =
+      instanceMethod()
+          .onDescendantOf("reactor.core.publisher.Flux")
+          .namedAnyOf("toIterable", "toStream")
+          .withNoParameters();
+  private static final Supplier<Type> STREAM = Suppliers.typeFromString(Stream.class.getName());
+
+  /** Instantiates a new {@link FluxImplicitBlock} instance. */
+  public FluxImplicitBlock() {}
+
+  @Override
+  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+    if (!FLUX_WITH_IMPLICIT_BLOCK.matches(tree, state)) {
+      return Description.NO_MATCH;
+    }
+
+    Description.Builder description =
+        buildDescription(tree).addFix(SuggestedFixes.addSuppressWarnings(state, canonicalName()));
+    if (ThirdPartyLibrary.GUAVA.isIntroductionAllowed(state)) {
+      description.addFix(
+          suggestBlockingElementCollection(
+              tree, "com.google.common.collect.ImmutableList.toImmutableList", state));
+    }
+    description.addFix(
+        suggestBlockingElementCollection(tree, "java.util.stream.Collectors.toList", state));
+
+    return description.build();
+  }
+
+  private static SuggestedFix suggestBlockingElementCollection(
+      MethodInvocationTree tree, String fullyQualifiedCollectorMethod, VisitorState state) {
+    SuggestedFix.Builder importSuggestion = SuggestedFix.builder();
+    String replacementMethodInvocation =
+        SuggestedFixes.qualifyStaticImport(fullyQualifiedCollectorMethod, importSuggestion, state);
+
+    boolean isStream =
+        ASTHelpers.isSubtype(ASTHelpers.getResultType(tree), STREAM.get(state), state);
+    String replacement =
+        String.format(
+            ".collect(%s()).block()%s", replacementMethodInvocation, isStream ? ".stream()" : "");
+    return importSuggestion.merge(replaceMethodInvocation(tree, replacement, state)).build();
+  }
+
+  private static SuggestedFix.Builder replaceMethodInvocation(
+      MethodInvocationTree tree, String replacement, VisitorState state) {
+    int startPosition = state.getEndPosition(ASTHelpers.getReceiver(tree));
+    int endPosition = state.getEndPosition(tree);
+
+    checkState(
+        startPosition != Position.NOPOS && endPosition != Position.NOPOS,
+        "Cannot locate method to be replaced in source code");
+
+    return SuggestedFix.builder().replace(startPosition, endPosition, replacement);
+  }
+}

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/IdentityConversion.java

@@ -35,6 +35,8 @@ import tech.picnic.errorprone.bugpatterns.util.SourceCode;
 // XXX: Consider detecting cases where a flagged expression is passed to a method, and where removal
 // of the identity conversion would cause a different method overload to be selected. Depending on
 // the target method such a modification may change the code's semantics or performance.
+// XXX: Also flag `Stream#map`, `Mono#map` and `Flux#map` invocations where the given transformation
+// is effectively the identity operation.
 @AutoService(BugChecker.class)
 @BugPattern(
     summary = "Avoid or clarify identity conversions",

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/JUnitValueSource.java

@@ -0,0 +1,307 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
+import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
+import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
+import static com.google.errorprone.matchers.ChildMultiMatcher.MatchType.ALL;
+import static com.google.errorprone.matchers.ChildMultiMatcher.MatchType.AT_LEAST_ONE;
+import static com.google.errorprone.matchers.Matchers.allOf;
+import static com.google.errorprone.matchers.Matchers.anyOf;
+import static com.google.errorprone.matchers.Matchers.anything;
+import static com.google.errorprone.matchers.Matchers.argument;
+import static com.google.errorprone.matchers.Matchers.argumentCount;
+import static com.google.errorprone.matchers.Matchers.classLiteral;
+import static com.google.errorprone.matchers.Matchers.hasArguments;
+import static com.google.errorprone.matchers.Matchers.isPrimitiveOrBoxedPrimitiveType;
+import static com.google.errorprone.matchers.Matchers.isSameType;
+import static com.google.errorprone.matchers.Matchers.methodHasParameters;
+import static com.google.errorprone.matchers.Matchers.staticMethod;
+import static com.google.errorprone.matchers.Matchers.toType;
+import static java.util.function.Predicate.not;
+import static java.util.stream.Collectors.joining;
+import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.bugpatterns.util.MoreJUnitMatchers.HAS_METHOD_SOURCE;
+import static tech.picnic.errorprone.bugpatterns.util.MoreJUnitMatchers.getMethodSourceFactoryNames;
+
+import com.google.auto.service.AutoService;
+import com.google.common.collect.Iterables;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.MethodTreeMatcher;
+import com.google.errorprone.fixes.SuggestedFix;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
+import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.AnnotationTree;
+import com.sun.source.tree.ClassTree;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.LambdaExpressionTree;
+import com.sun.source.tree.MethodInvocationTree;
+import com.sun.source.tree.MethodTree;
+import com.sun.source.tree.NewArrayTree;
+import com.sun.source.tree.ReturnTree;
+import com.sun.source.util.TreeScanner;
+import com.sun.tools.javac.code.Type;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Locale;
+import java.util.Optional;
+import java.util.Set;
+import java.util.function.Predicate;
+import java.util.stream.DoubleStream;
+import java.util.stream.IntStream;
+import java.util.stream.LongStream;
+import java.util.stream.Stream;
+import org.jspecify.annotations.Nullable;
+import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+
+/**
+ * A {@link BugChecker} that flags JUnit tests with a {@link
+ * org.junit.jupiter.params.provider.MethodSource} annotation that can be replaced with an
+ * equivalent {@link org.junit.jupiter.params.provider.ValueSource} annotation.
+ */
+// XXX: Where applicable, also flag `@MethodSource` annotations that reference multiple value
+// factory methods (or that repeat the same value factory method multiple times).
+// XXX: Support inlining of overloaded value factory methods.
+// XXX: Support inlining of value factory methods referenced by multiple `@MethodSource`
+// annotations.
+// XXX: Support value factory return expressions of the form `Stream.of(a, b,
+// c).map(Arguments::argument)`.
+// XXX: Support simplification of test methods that accept additional injected parameters such as
+// `TestInfo`; such parameters should be ignored for the purpose of this check.
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary = "Prefer `@ValueSource` over a `@MethodSource` where possible and reasonable",
+    linkType = CUSTOM,
+    link = BUG_PATTERNS_BASE_URL + "JUnitValueSource",
+    severity = SUGGESTION,
+    tags = SIMPLIFICATION)
+public final class JUnitValueSource extends BugChecker implements MethodTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Matcher<ExpressionTree> SUPPORTED_VALUE_FACTORY_VALUES =
+      anyOf(
+          isArrayArgumentValueCandidate(),
+          toType(
+              MethodInvocationTree.class,
+              allOf(
+                  staticMethod()
+                      .onClass("org.junit.jupiter.params.provider.Arguments")
+                      .namedAnyOf("arguments", "of"),
+                  argumentCount(1),
+                  argument(0, isArrayArgumentValueCandidate()))));
+  private static final Matcher<ExpressionTree> ARRAY_OF_SUPPORTED_SINGLE_VALUE_ARGUMENTS =
+      isSingleDimensionArrayCreationWithAllElementsMatching(SUPPORTED_VALUE_FACTORY_VALUES);
+  private static final Matcher<ExpressionTree> ENUMERATION_OF_SUPPORTED_SINGLE_VALUE_ARGUMENTS =
+      toType(
+          MethodInvocationTree.class,
+          allOf(
+              staticMethod()
+                  .onClassAny(
+                      Stream.class.getName(),
+                      IntStream.class.getName(),
+                      LongStream.class.getName(),
+                      DoubleStream.class.getName(),
+                      List.class.getName(),
+                      Set.class.getName(),
+                      "com.google.common.collect.ImmutableList",
+                      "com.google.common.collect.ImmutableSet")
+                  .named("of"),
+              hasArguments(AT_LEAST_ONE, anything()),
+              hasArguments(ALL, SUPPORTED_VALUE_FACTORY_VALUES)));
+  private static final Matcher<MethodTree> IS_UNARY_METHOD_WITH_SUPPORTED_PARAMETER =
+      methodHasParameters(
+          anyOf(
+              isPrimitiveOrBoxedPrimitiveType(),
+              isSameType(String.class),
+              isSameType(state -> state.getSymtab().classType)));
+
+  /** Instantiates a new {@link JUnitValueSource} instance. */
+  public JUnitValueSource() {}
+
+  @Override
+  public Description matchMethod(MethodTree tree, VisitorState state) {
+    if (!IS_UNARY_METHOD_WITH_SUPPORTED_PARAMETER.matches(tree, state)) {
+      return Description.NO_MATCH;
+    }
+
+    Type parameterType = ASTHelpers.getType(Iterables.getOnlyElement(tree.getParameters()));
+
+    return findMethodSourceAnnotation(tree, state)
+        .flatMap(
+            methodSourceAnnotation ->
+                getSoleLocalFactoryName(methodSourceAnnotation, tree)
+                    .filter(factory -> !hasSiblingReferencingValueFactory(tree, factory, state))
+                    .flatMap(factory -> findSiblingWithName(tree, factory, state))
+                    .flatMap(
+                        factoryMethod ->
+                            tryConstructValueSourceFix(
+                                parameterType, methodSourceAnnotation, factoryMethod, state))
+                    .map(fix -> describeMatch(methodSourceAnnotation, fix)))
+        .orElse(Description.NO_MATCH);
+  }
+
+  /**
+   * Returns the name of the value factory method pointed to by the given {@code @MethodSource}
+   * annotation, if it (a) is the only one and (b) is a method in the same class as the annotated
+   * method.
+   */
+  private static Optional<String> getSoleLocalFactoryName(
+      AnnotationTree methodSourceAnnotation, MethodTree method) {
+    return getElementIfSingleton(getMethodSourceFactoryNames(methodSourceAnnotation, method))
+        .filter(name -> name.indexOf('#') < 0);
+  }
+
+  /**
+   * Tells whether the given method has a sibling method in the same class that depends on the
+   * specified value factory method.
+   */
+  private static boolean hasSiblingReferencingValueFactory(
+      MethodTree tree, String valueFactory, VisitorState state) {
+    return findMatchingSibling(tree, m -> hasValueFactory(m, valueFactory, state), state)
+        .isPresent();
+  }
+
+  private static Optional<MethodTree> findSiblingWithName(
+      MethodTree tree, String methodName, VisitorState state) {
+    return findMatchingSibling(tree, m -> m.getName().contentEquals(methodName), state);
+  }
+
+  private static Optional<MethodTree> findMatchingSibling(
+      MethodTree tree, Predicate<? super MethodTree> predicate, VisitorState state) {
+    return state.findEnclosing(ClassTree.class).getMembers().stream()
+        .filter(MethodTree.class::isInstance)
+        .map(MethodTree.class::cast)
+        .filter(not(tree::equals))
+        .filter(predicate)
+        .findFirst();
+  }
+
+  private static boolean hasValueFactory(
+      MethodTree tree, String valueFactoryMethodName, VisitorState state) {
+    return findMethodSourceAnnotation(tree, state).stream()
+        .anyMatch(
+            annotation ->
+                getMethodSourceFactoryNames(annotation, tree).contains(valueFactoryMethodName));
+  }
+
+  private static Optional<AnnotationTree> findMethodSourceAnnotation(
+      MethodTree tree, VisitorState state) {
+    return HAS_METHOD_SOURCE.multiMatchResult(tree, state).matchingNodes().stream().findFirst();
+  }
+
+  private static Optional<SuggestedFix> tryConstructValueSourceFix(
+      Type parameterType,
+      AnnotationTree methodSourceAnnotation,
+      MethodTree valueFactoryMethod,
+      VisitorState state) {
+    return getSingleReturnExpression(valueFactoryMethod)
+        .flatMap(expression -> tryExtractValueSourceAttributeValue(expression, state))
+        .map(
+            valueSourceAttributeValue ->
+                SuggestedFix.builder()
+                    .addImport("org.junit.jupiter.params.provider.ValueSource")
+                    .replace(
+                        methodSourceAnnotation,
+                        String.format(
+                            "@ValueSource(%s = %s)",
+                            toValueSourceAttributeName(parameterType), valueSourceAttributeValue))
+                    .delete(valueFactoryMethod)
+                    .build());
+  }
+
+  // XXX: This pattern also occurs a few times inside Error Prone; contribute upstream.
+  private static Optional<ExpressionTree> getSingleReturnExpression(MethodTree methodTree) {
+    List<ExpressionTree> returnExpressions = new ArrayList<>();
+    new TreeScanner<@Nullable Void, @Nullable Void>() {
+      @Override
+      public @Nullable Void visitClass(ClassTree node, @Nullable Void unused) {
+        /* Ignore `return` statements inside anonymous/local classes. */
+        return null;
+      }
+
+      @Override
+      public @Nullable Void visitReturn(ReturnTree node, @Nullable Void unused) {
+        returnExpressions.add(node.getExpression());
+        return super.visitReturn(node, unused);
+      }
+
+      @Override
+      public @Nullable Void visitLambdaExpression(
+          LambdaExpressionTree node, @Nullable Void unused) {
+        /* Ignore `return` statements inside lambda expressions. */
+        return null;
+      }
+    }.scan(methodTree, null);
+
+    return getElementIfSingleton(returnExpressions);
+  }
+
+  private static Optional<String> tryExtractValueSourceAttributeValue(
+      ExpressionTree tree, VisitorState state) {
+    List<? extends ExpressionTree> arguments;
+    if (ENUMERATION_OF_SUPPORTED_SINGLE_VALUE_ARGUMENTS.matches(tree, state)) {
+      arguments = ((MethodInvocationTree) tree).getArguments();
+    } else if (ARRAY_OF_SUPPORTED_SINGLE_VALUE_ARGUMENTS.matches(tree, state)) {
+      arguments = ((NewArrayTree) tree).getInitializers();
+    } else {
+      return Optional.empty();
+    }
+
+    /*
+     * Join the values into a comma-separated string, unwrapping `Arguments` factory method
+     * invocations if applicable.
+     */
+    return Optional.of(
+            arguments.stream()
+                .map(
+                    arg ->
+                        arg instanceof MethodInvocationTree
+                            ? Iterables.getOnlyElement(((MethodInvocationTree) arg).getArguments())
+                            : arg)
+                .map(argument -> SourceCode.treeToString(argument, state))
+                .collect(joining(", ")))
+        .map(value -> arguments.size() > 1 ? String.format("{%s}", value) : value);
+  }
+
+  private static String toValueSourceAttributeName(Type type) {
+    String typeString = type.tsym.name.toString();
+
+    switch (typeString) {
+      case "Class":
+        return "classes";
+      case "Character":
+        return "chars";
+      case "Integer":
+        return "ints";
+      default:
+        return typeString.toLowerCase(Locale.ROOT) + 's';
+    }
+  }
+
+  private static <T> Optional<T> getElementIfSingleton(Collection<T> collection) {
+    return Optional.of(collection)
+        .filter(elements -> elements.size() == 1)
+        .map(Iterables::getOnlyElement);
+  }
+
+  private static Matcher<ExpressionTree> isSingleDimensionArrayCreationWithAllElementsMatching(
+      Matcher<? super ExpressionTree> elementMatcher) {
+    return (tree, state) -> {
+      if (!(tree instanceof NewArrayTree)) {
+        return false;
+      }
+
+      NewArrayTree newArray = (NewArrayTree) tree;
+      return newArray.getDimensions().isEmpty()
+          && !newArray.getInitializers().isEmpty()
+          && newArray.getInitializers().stream()
+              .allMatch(element -> elementMatcher.matches(element, state));
+    };
+  }
+
+  private static Matcher<ExpressionTree> isArrayArgumentValueCandidate() {
+    return anyOf(classLiteral(anything()), (tree, state) -> ASTHelpers.constValue(tree) != null);
+  }
+}

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/LexicographicalAnnotationAttributeListing.java

@@ -40,6 +40,7 @@ import java.util.List;
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Stream;
+import javax.inject.Inject;
 import org.jspecify.annotations.Nullable;
 import tech.picnic.errorprone.bugpatterns.util.AnnotationAttributeMatcher;
 import tech.picnic.errorprone.bugpatterns.util.Flags;
@@ -58,6 +59,7 @@ import tech.picnic.errorprone.bugpatterns.util.SourceCode;
     linkType = CUSTOM,
     severity = SUGGESTION,
     tags = STYLE)
+@SuppressWarnings("java:S2160" /* Super class equality definition suffices. */)
 public final class LexicographicalAnnotationAttributeListing extends BugChecker
     implements AnnotationTreeMatcher {
   private static final long serialVersionUID = 1L;
@@ -93,7 +95,8 @@ public final class LexicographicalAnnotationAttributeListing extends BugChecker
    *
    * @param flags Any provided command line flags.
    */
-  public LexicographicalAnnotationAttributeListing(ErrorProneFlags flags) {
+  @Inject
+  LexicographicalAnnotationAttributeListing(ErrorProneFlags flags) {
     matcher = createAnnotationAttributeMatcher(flags);
   }
 

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/LexicographicalAnnotationListing.java

@@ -46,9 +46,19 @@ import tech.picnic.errorprone.bugpatterns.util.SourceCode;
 public final class LexicographicalAnnotationListing extends BugChecker
     implements MethodTreeMatcher {
   private static final long serialVersionUID = 1L;
+  /**
+   * A comparator that minimally reorders {@link AnnotationType}s, such that declaration annotations
+   * are placed before type annotations.
+   */
+  @SuppressWarnings({
+    "java:S1067",
+    "java:S3358"
+  } /* Avoiding the nested ternary operator hurts readability. */)
   private static final Comparator<@Nullable AnnotationType> BY_ANNOTATION_TYPE =
       (a, b) ->
-          (a == null || a == DECLARATION) && b == TYPE ? -1 : a == TYPE && b == DECLARATION ? 1 : 0;
+          (a == null || a == DECLARATION) && b == TYPE
+              ? -1
+              : (a == TYPE && b == DECLARATION ? 1 : 0);
 
   /** Instantiates a new {@link LexicographicalAnnotationListing} instance. */
   public LexicographicalAnnotationListing() {}

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/MethodReferenceUsage.java

@@ -118,6 +118,8 @@ public final class MethodReferenceUsage extends BugChecker implements LambdaExpr
         .flatMap(expectedInstance -> constructMethodRef(lambdaExpr, subTree, expectedInstance));
   }
 
+  @SuppressWarnings(
+      "java:S1151" /* Extracting `IDENTIFIER` case block to separate method does not improve readability. */)
   private static Optional<SuggestedFix.Builder> constructMethodRef(
       LambdaExpressionTree lambdaExpr,
       MethodInvocationTree subTree,
@@ -130,10 +132,9 @@ public final class MethodReferenceUsage extends BugChecker implements LambdaExpr
           return Optional.empty();
         }
         Symbol sym = ASTHelpers.getSymbol(methodSelect);
-        if (!ASTHelpers.isStatic(sym)) {
-          return constructFix(lambdaExpr, "this", methodSelect);
-        }
-        return constructFix(lambdaExpr, sym.owner, methodSelect);
+        return ASTHelpers.isStatic(sym)
+            ? constructFix(lambdaExpr, sym.owner, methodSelect)
+            : constructFix(lambdaExpr, "this", methodSelect);
       case MEMBER_SELECT:
         return constructMethodRef(lambdaExpr, (MemberSelectTree) methodSelect, expectedInstance);
       default:

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/MissingRefasterAnnotation.java

@@ -1,59 +0,0 @@
-package tech.picnic.errorprone.bugpatterns;
-
-import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
-import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
-import static com.google.errorprone.BugPattern.StandardTags.LIKELY_ERROR;
-import static com.google.errorprone.matchers.ChildMultiMatcher.MatchType.AT_LEAST_ONE;
-import static com.google.errorprone.matchers.Matchers.annotations;
-import static com.google.errorprone.matchers.Matchers.anyOf;
-import static com.google.errorprone.matchers.Matchers.isType;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
-
-import com.google.auto.service.AutoService;
-import com.google.errorprone.BugPattern;
-import com.google.errorprone.VisitorState;
-import com.google.errorprone.bugpatterns.BugChecker;
-import com.google.errorprone.bugpatterns.BugChecker.ClassTreeMatcher;
-import com.google.errorprone.matchers.Description;
-import com.google.errorprone.matchers.MultiMatcher;
-import com.google.errorprone.util.ASTHelpers;
-import com.sun.source.tree.AnnotationTree;
-import com.sun.source.tree.ClassTree;
-import com.sun.source.tree.MethodTree;
-import com.sun.source.tree.Tree;
-
-/** A {@link BugChecker} that flags likely missing Refaster annotations. */
-@AutoService(BugChecker.class)
-@BugPattern(
-    summary = "The Refaster rule contains a method without any Refaster annotations",
-    link = BUG_PATTERNS_BASE_URL + "MissingRefasterAnnotation",
-    linkType = CUSTOM,
-    severity = WARNING,
-    tags = LIKELY_ERROR)
-public final class MissingRefasterAnnotation extends BugChecker implements ClassTreeMatcher {
-  private static final long serialVersionUID = 1L;
-  private static final MultiMatcher<Tree, AnnotationTree> REFASTER_ANNOTATION =
-      annotations(
-          AT_LEAST_ONE,
-          anyOf(
-              isType("com.google.errorprone.refaster.annotation.Placeholder"),
-              isType("com.google.errorprone.refaster.annotation.BeforeTemplate"),
-              isType("com.google.errorprone.refaster.annotation.AfterTemplate")));
-
-  /** Instantiates a new {@link MissingRefasterAnnotation} instance. */
-  public MissingRefasterAnnotation() {}
-
-  @Override
-  public Description matchClass(ClassTree tree, VisitorState state) {
-    long methodTypes =
-        tree.getMembers().stream()
-            .filter(member -> member.getKind() == Tree.Kind.METHOD)
-            .map(MethodTree.class::cast)
-            .filter(method -> !ASTHelpers.isGeneratedConstructor(method))
-            .map(method -> REFASTER_ANNOTATION.matches(method, state))
-            .distinct()
-            .count();
-
-    return methodTypes < 2 ? Description.NO_MATCH : buildDescription(tree).build();
-  }
-}

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/MockitoMockClassReference.java

@@ -0,0 +1,86 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
+import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
+import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
+import static com.google.errorprone.matchers.Matchers.allOf;
+import static com.google.errorprone.matchers.Matchers.argument;
+import static com.google.errorprone.matchers.Matchers.isSameType;
+import static com.google.errorprone.matchers.Matchers.isVariable;
+import static com.google.errorprone.matchers.Matchers.not;
+import static com.google.errorprone.matchers.Matchers.staticMethod;
+import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+
+import com.google.auto.service.AutoService;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
+import com.google.errorprone.fixes.SuggestedFixes;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
+import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.MethodInvocationTree;
+import com.sun.source.tree.Tree;
+import com.sun.source.tree.VariableTree;
+import java.util.List;
+import tech.picnic.errorprone.bugpatterns.util.MoreASTHelpers;
+
+/**
+ * A {@link BugChecker} that flags the use of {@link org.mockito.Mockito#mock(Class)} and {@link
+ * org.mockito.Mockito#spy(Class)} where instead the type to be mocked or spied can be derived from
+ * context.
+ */
+// XXX: This check currently does not flag method invocation arguments. When adding support for
+// this, consider that in some cases the type to be mocked or spied must be specified explicitly so
+// as to disambiguate between method overloads.
+// XXX: This check currently does not flag (implicit or explicit) lambda return expressions.
+// XXX: This check currently does not drop suppressions that become obsolete after the
+// suggested fix is applied; consider adding support for this.
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary = "Don't unnecessarily pass a type to Mockito's `mock(Class)` and `spy(Class)` methods",
+    link = BUG_PATTERNS_BASE_URL + "MockitoMockClassReference",
+    linkType = CUSTOM,
+    severity = SUGGESTION,
+    tags = SIMPLIFICATION)
+public final class MockitoMockClassReference extends BugChecker
+    implements MethodInvocationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Matcher<MethodInvocationTree> MOCKITO_MOCK_OR_SPY_WITH_HARDCODED_TYPE =
+      allOf(
+          argument(0, allOf(isSameType(Class.class.getName()), not(isVariable()))),
+          staticMethod().onClass("org.mockito.Mockito").namedAnyOf("mock", "spy"));
+
+  /** Instantiates a new {@link MockitoMockClassReference} instance. */
+  public MockitoMockClassReference() {}
+
+  @Override
+  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+    if (!MOCKITO_MOCK_OR_SPY_WITH_HARDCODED_TYPE.matches(tree, state)
+        || !isTypeDerivableFromContext(tree, state)) {
+      return Description.NO_MATCH;
+    }
+
+    List<? extends ExpressionTree> arguments = tree.getArguments();
+    return describeMatch(tree, SuggestedFixes.removeElement(arguments.get(0), arguments, state));
+  }
+
+  private static boolean isTypeDerivableFromContext(MethodInvocationTree tree, VisitorState state) {
+    Tree parent = state.getPath().getParentPath().getLeaf();
+    switch (parent.getKind()) {
+      case VARIABLE:
+        return !ASTHelpers.hasNoExplicitType((VariableTree) parent, state)
+            && MoreASTHelpers.areSameType(tree, parent, state);
+      case ASSIGNMENT:
+        return MoreASTHelpers.areSameType(tree, parent, state);
+      case RETURN:
+        return MoreASTHelpers.findMethodExitedOnReturn(state)
+            .filter(m -> MoreASTHelpers.areSameType(tree, m.getReturnType(), state))
+            .isPresent();
+      default:
+        return false;
+    }
+  }
+}

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/MongoDBTextFilterUsage.java

@@ -0,0 +1,47 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
+import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
+import static com.google.errorprone.BugPattern.StandardTags.PERFORMANCE;
+import static com.google.errorprone.matchers.method.MethodMatchers.staticMethod;
+import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+
+import com.google.auto.service.AutoService;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.MethodInvocationTree;
+
+/**
+ * A {@link BugChecker} that flags usages of MongoDB {@code $text} filter usages.
+ *
+ * @see <a href="https://www.mongodb.com/docs/manual/text-search/">MongoDB Text Search</a>
+ */
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary =
+        "Avoid MongoDB's `$text` filter operator, as it can trigger heavy queries and even cause the server to run out of memory",
+    link = BUG_PATTERNS_BASE_URL + "MongoDBTextFilterUsage",
+    linkType = CUSTOM,
+    severity = SUGGESTION,
+    tags = PERFORMANCE)
+public final class MongoDBTextFilterUsage extends BugChecker
+    implements MethodInvocationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Matcher<ExpressionTree> MONGO_FILTERS_TEXT_METHOD =
+      staticMethod().onClass("com.mongodb.client.model.Filters").named("text");
+
+  /** Instantiates a new {@link MongoDBTextFilterUsage} instance. */
+  public MongoDBTextFilterUsage() {}
+
+  @Override
+  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+    return MONGO_FILTERS_TEXT_METHOD.matches(tree, state)
+        ? describeMatch(tree)
+        : Description.NO_MATCH;
+  }
+}

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/NestedOptionals.java

@@ -4,6 +4,7 @@ import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
 import static com.google.errorprone.BugPattern.StandardTags.FRAGILE_CODE;
 import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.bugpatterns.util.MoreMatchers.isSubTypeOf;
 import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.generic;
 import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.raw;
 import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.subOf;
@@ -14,14 +15,19 @@ import com.google.errorprone.VisitorState;
 import com.google.errorprone.bugpatterns.BugChecker;
 import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
 import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
 import com.google.errorprone.suppliers.Supplier;
 import com.google.errorprone.suppliers.Suppliers;
-import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.MethodInvocationTree;
+import com.sun.source.tree.Tree;
 import com.sun.tools.javac.code.Type;
 import java.util.Optional;
 
 /** A {@link BugChecker} that flags nesting of {@link Optional Optionals}. */
+// XXX: Extend this checker to also flag method return types and variable/field types.
+// XXX: Consider generalizing this checker and `NestedPublishers` to a single `NestedMonad` check,
+// which e.g. also flags nested `Stream`s. Alternatively, combine these and other checkers into an
+// even more generic `ConfusingType` checker.
 @AutoService(BugChecker.class)
 @BugPattern(
     summary =
@@ -33,19 +39,16 @@ import java.util.Optional;
 public final class NestedOptionals extends BugChecker implements MethodInvocationTreeMatcher {
   private static final long serialVersionUID = 1L;
   private static final Supplier<Type> OPTIONAL = Suppliers.typeFromClass(Optional.class);
-  private static final Supplier<Type> OPTIONAL_OF_OPTIONAL =
-      VisitorState.memoize(generic(OPTIONAL, subOf(raw(OPTIONAL))));
+  private static final Matcher<Tree> IS_OPTIONAL_OF_OPTIONAL =
+      isSubTypeOf(VisitorState.memoize(generic(OPTIONAL, subOf(raw(OPTIONAL)))));
 
   /** Instantiates a new {@link NestedOptionals} instance. */
   public NestedOptionals() {}
 
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
-    Type type = OPTIONAL_OF_OPTIONAL.get(state);
-    if (type == null || !state.getTypes().isSubtype(ASTHelpers.getType(tree), type)) {
-      return Description.NO_MATCH;
-    }
-
-    return describeMatch(tree);
+    return IS_OPTIONAL_OF_OPTIONAL.matches(tree, state)
+        ? describeMatch(tree)
+        : Description.NO_MATCH;
   }
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/NestedPublishers.java

@@ -0,0 +1,63 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
+import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
+import static com.google.errorprone.BugPattern.StandardTags.FRAGILE_CODE;
+import static com.google.errorprone.matchers.Matchers.typePredicateMatcher;
+import static com.google.errorprone.predicates.TypePredicates.allOf;
+import static com.google.errorprone.predicates.TypePredicates.not;
+import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.bugpatterns.util.MoreTypePredicates.hasTypeParameter;
+import static tech.picnic.errorprone.bugpatterns.util.MoreTypePredicates.isSubTypeOf;
+import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.generic;
+import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.raw;
+import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.subOf;
+import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.type;
+
+import com.google.auto.service.AutoService;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
+import com.google.errorprone.suppliers.Supplier;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.MethodInvocationTree;
+import com.sun.tools.javac.code.Type;
+
+/**
+ * A {@link BugChecker} that flags {@code Publisher<? extends Publisher>} instances, unless the
+ * nested {@link org.reactivestreams.Publisher} is a {@link reactor.core.publisher.GroupedFlux}.
+ */
+// XXX: See the `NestedOptionals` check for some ideas on how to generalize this kind of checker.
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary =
+        "Avoid `Publisher`s that emit other `Publishers`s; "
+            + "the resultant code is hard to reason about",
+    link = BUG_PATTERNS_BASE_URL + "NestedPublishers",
+    linkType = CUSTOM,
+    severity = WARNING,
+    tags = FRAGILE_CODE)
+public final class NestedPublishers extends BugChecker implements MethodInvocationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Supplier<Type> PUBLISHER = type("org.reactivestreams.Publisher");
+  private static final Matcher<ExpressionTree> IS_NON_GROUPED_PUBLISHER_OF_PUBLISHERS =
+      typePredicateMatcher(
+          allOf(
+              isSubTypeOf(generic(PUBLISHER, subOf(raw(PUBLISHER)))),
+              not(
+                  hasTypeParameter(
+                      0, isSubTypeOf(raw(type("reactor.core.publisher.GroupedFlux")))))));
+
+  /** Instantiates a new {@link NestedPublishers} instance. */
+  public NestedPublishers() {}
+
+  @Override
+  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+    return IS_NON_GROUPED_PUBLISHER_OF_PUBLISHERS.matches(tree, state)
+        ? describeMatch(tree)
+        : Description.NO_MATCH;
+  }
+}

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/NonEmptyMono.java

@@ -43,6 +43,7 @@ import tech.picnic.errorprone.bugpatterns.util.SourceCode;
 // emitting a value (e.g. `Mono.empty()`, `someFlux.then()`, ...), or known not to complete normally
 // (`Mono.never()`, `someFlux.repeat()`, `Mono.error(...)`, ...). The latter category could
 // potentially be split out further.
+@SuppressWarnings("java:S1192" /* Factoring out repeated method names impacts readability. */)
 public final class NonEmptyMono extends BugChecker implements MethodInvocationTreeMatcher {
   private static final long serialVersionUID = 1L;
   private static final Matcher<ExpressionTree> MONO_SIZE_CHECK =

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/PrimitiveComparison.java

@@ -49,6 +49,7 @@ import tech.picnic.errorprone.bugpatterns.util.SourceCode;
     linkType = CUSTOM,
     severity = WARNING,
     tags = PERFORMANCE)
+@SuppressWarnings("java:S1192" /* Factoring out repeated method names impacts readability. */)
 public final class PrimitiveComparison extends BugChecker implements MethodInvocationTreeMatcher {
   private static final long serialVersionUID = 1L;
   private static final Matcher<ExpressionTree> STATIC_COMPARISON_METHOD =

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RedundantStringConversion.java

@@ -7,6 +7,7 @@ import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
 import static com.google.errorprone.matchers.Matchers.allOf;
 import static com.google.errorprone.matchers.Matchers.anyMethod;
 import static com.google.errorprone.matchers.Matchers.anyOf;
+import static com.google.errorprone.matchers.Matchers.anything;
 import static com.google.errorprone.matchers.Matchers.argumentCount;
 import static com.google.errorprone.matchers.Matchers.isNonNullUsingDataflow;
 import static com.google.errorprone.matchers.Matchers.isSameType;
@@ -49,6 +50,7 @@ import java.util.Locale;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Stream;
+import javax.inject.Inject;
 import tech.picnic.errorprone.bugpatterns.util.Flags;
 import tech.picnic.errorprone.bugpatterns.util.MethodMatcherFactory;
 import tech.picnic.errorprone.bugpatterns.util.SourceCode;
@@ -61,15 +63,18 @@ import tech.picnic.errorprone.bugpatterns.util.SourceCode;
     linkType = CUSTOM,
     severity = SUGGESTION,
     tags = SIMPLIFICATION)
+@SuppressWarnings({
+  "java:S1192" /* Factoring out repeated method names impacts readability. */,
+  "java:S2160" /* Super class equality definition suffices. */,
+  "key-to-resolve-AnnotationUseStyle-and-TrailingComment-check-conflict"
+})
 public final class RedundantStringConversion extends BugChecker
     implements BinaryTreeMatcher, CompoundAssignmentTreeMatcher, MethodInvocationTreeMatcher {
   private static final long serialVersionUID = 1L;
   private static final String EXTRA_STRING_CONVERSION_METHODS_FLAG =
       "RedundantStringConversion:ExtraConversionMethods";
 
-  @SuppressWarnings("UnnecessaryLambda")
-  private static final Matcher<ExpressionTree> ANY_EXPR = (t, s) -> true;
-
+  private static final Matcher<ExpressionTree> ANY_EXPR = anything();
   private static final Matcher<ExpressionTree> LOCALE = isSameType(Locale.class);
   private static final Matcher<ExpressionTree> MARKER = isSubtypeOf("org.slf4j.Marker");
   private static final Matcher<ExpressionTree> STRING = isSameType(String.class);
@@ -151,7 +156,8 @@ public final class RedundantStringConversion extends BugChecker
    *
    * @param flags Any provided command line flags.
    */
-  public RedundantStringConversion(ErrorProneFlags flags) {
+  @Inject
+  RedundantStringConversion(ErrorProneFlags flags) {
     conversionMethodMatcher = createConversionMethodMatcher(flags);
   }
 
@@ -164,7 +170,7 @@ public final class RedundantStringConversion extends BugChecker
     ExpressionTree lhs = tree.getLeftOperand();
     ExpressionTree rhs = tree.getRightOperand();
     if (!STRING.matches(lhs, state)) {
-      return finalize(tree, tryFix(rhs, state, STRING));
+      return createDescription(tree, tryFix(rhs, state, STRING));
     }
 
     List<SuggestedFix.Builder> fixes = new ArrayList<>();
@@ -178,7 +184,7 @@ public final class RedundantStringConversion extends BugChecker
     }
     tryFix(rhs, state, ANY_EXPR).ifPresent(fixes::add);
 
-    return finalize(tree, fixes.stream().reduce(SuggestedFix.Builder::merge));
+    return createDescription(tree, fixes.stream().reduce(SuggestedFix.Builder::merge));
   }
 
   @Override
@@ -187,36 +193,36 @@ public final class RedundantStringConversion extends BugChecker
       return Description.NO_MATCH;
     }
 
-    return finalize(tree, tryFix(tree.getExpression(), state, ANY_EXPR));
+    return createDescription(tree, tryFix(tree.getExpression(), state, ANY_EXPR));
   }
 
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     if (STRINGBUILDER_APPEND_INVOCATION.matches(tree, state)) {
-      return finalize(tree, tryFixPositionalConverter(tree.getArguments(), state, 0));
+      return createDescription(tree, tryFixPositionalConverter(tree.getArguments(), state, 0));
     }
 
     if (STRINGBUILDER_INSERT_INVOCATION.matches(tree, state)) {
-      return finalize(tree, tryFixPositionalConverter(tree.getArguments(), state, 1));
+      return createDescription(tree, tryFixPositionalConverter(tree.getArguments(), state, 1));
     }
 
     if (FORMATTER_INVOCATION.matches(tree, state)) {
-      return finalize(tree, tryFixFormatter(tree.getArguments(), state));
+      return createDescription(tree, tryFixFormatter(tree.getArguments(), state));
     }
 
     if (GUAVA_GUARD_INVOCATION.matches(tree, state)) {
-      return finalize(tree, tryFixGuavaGuard(tree.getArguments(), state));
+      return createDescription(tree, tryFixGuavaGuard(tree.getArguments(), state));
     }
 
     if (SLF4J_LOGGER_INVOCATION.matches(tree, state)) {
-      return finalize(tree, tryFixSlf4jLogger(tree.getArguments(), state));
+      return createDescription(tree, tryFixSlf4jLogger(tree.getArguments(), state));
     }
 
     if (instanceMethod().matches(tree, state)) {
-      return finalize(tree, tryFix(tree, state, STRING));
+      return createDescription(tree, tryFix(tree, state, STRING));
     }
 
-    return finalize(tree, tryFix(tree, state, NON_NULL_STRING));
+    return createDescription(tree, tryFix(tree, state, NON_NULL_STRING));
   }
 
   private Optional<SuggestedFix.Builder> tryFixPositionalConverter(
@@ -299,7 +305,7 @@ public final class RedundantStringConversion extends BugChecker
 
     /* Simplify the values to be plugged into the format pattern, if possible. */
     return arguments.stream()
-        .skip(patternIndex + 1)
+        .skip(patternIndex + 1L)
         .map(arg -> tryFix(arg, state, remainingArgFilter))
         .flatMap(Optional::stream)
         .reduce(SuggestedFix.Builder::merge);
@@ -363,7 +369,7 @@ public final class RedundantStringConversion extends BugChecker
     return Optional.of(Iterables.getOnlyElement(methodInvocation.getArguments()));
   }
 
-  private Description finalize(Tree tree, Optional<SuggestedFix.Builder> fixes) {
+  private Description createDescription(Tree tree, Optional<SuggestedFix.Builder> fixes) {
     return fixes
         .map(SuggestedFix.Builder::build)
         .map(fix -> describeMatch(tree, fix))

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RequestMappingAnnotation.java

@@ -74,9 +74,13 @@ public final class RequestMappingAnnotation extends BugChecker implements Method
                   isSameType("java.time.ZoneId"),
                   isSameType("java.util.Locale"),
                   isSameType("java.util.TimeZone"),
+                  isSameType("jakarta.servlet.http.HttpServletRequest"),
+                  isSameType("jakarta.servlet.http.HttpServletResponse"),
                   isSameType("javax.servlet.http.HttpServletRequest"),
                   isSameType("javax.servlet.http.HttpServletResponse"),
                   isSameType("org.springframework.http.HttpMethod"),
+                  isSameType("org.springframework.ui.Model"),
+                  isSameType("org.springframework.validation.BindingResult"),
                   isSameType("org.springframework.web.context.request.NativeWebRequest"),
                   isSameType("org.springframework.web.context.request.WebRequest"),
                   isSameType("org.springframework.web.server.ServerWebExchange"),
@@ -95,8 +99,9 @@ public final class RequestMappingAnnotation extends BugChecker implements Method
             && LACKS_PARAMETER_ANNOTATION.matches(tree, state)
         ? buildDescription(tree)
             .setMessage(
-                "Not all parameters of this request mapping method are annotated; this may be a mistake. "
-                    + "If the unannotated parameters represent query string parameters, annotate them with `@RequestParam`.")
+                "Not all parameters of this request mapping method are annotated; this may be a "
+                    + "mistake. If the unannotated parameters represent query string parameters, "
+                    + "annotate them with `@RequestParam`.")
             .build()
         : Description.NO_MATCH;
   }

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RequestParamType.java

@@ -27,6 +27,7 @@ import com.google.errorprone.matchers.Matcher;
 import com.google.errorprone.suppliers.Suppliers;
 import com.sun.source.tree.Tree;
 import com.sun.source.tree.VariableTree;
+import javax.inject.Inject;
 import tech.picnic.errorprone.bugpatterns.util.Flags;
 
 /** A {@link BugChecker} that flags {@code @RequestParam} parameters with an unsupported type. */
@@ -38,6 +39,7 @@ import tech.picnic.errorprone.bugpatterns.util.Flags;
     linkType = CUSTOM,
     severity = ERROR,
     tags = LIKELY_ERROR)
+@SuppressWarnings("java:S2160" /* Super class equality definition suffices. */)
 public final class RequestParamType extends BugChecker implements VariableTreeMatcher {
   private static final long serialVersionUID = 1L;
   private static final String SUPPORTED_CUSTOM_TYPES_FLAG = "RequestParamType:SupportedCustomTypes";
@@ -54,7 +56,8 @@ public final class RequestParamType extends BugChecker implements VariableTreeMa
    *
    * @param flags Any provided command line flags.
    */
-  public RequestParamType(ErrorProneFlags flags) {
+  @Inject
+  RequestParamType(ErrorProneFlags flags) {
     hasUnsupportedRequestParamType = hasUnsupportedRequestParamType(flags);
   }
 

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/SourceCodeAvailability.java

@@ -0,0 +1,84 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.common.base.Verify.verify;
+import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
+import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
+import static java.util.stream.Collectors.joining;
+import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+
+import com.google.auto.service.AutoService;
+import com.google.common.collect.ImmutableSet;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.CompilationUnitTreeMatcher;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.CompilationUnitTree;
+import com.sun.source.tree.Tree;
+import com.sun.source.util.TreePath;
+import com.sun.source.util.TreeScanner;
+import java.util.ArrayDeque;
+import java.util.Deque;
+import java.util.LinkedHashSet;
+import java.util.Set;
+import org.jspecify.annotations.Nullable;
+import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+
+/** A {@link BugChecker} that files for which no accurate source code appears to be available. */
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary = "This type's source code is unavailable or inaccurate",
+    link = BUG_PATTERNS_BASE_URL + "SourceCodeAvailability",
+    linkType = CUSTOM,
+    severity = SUGGESTION)
+public final class SourceCodeAvailability extends BugChecker implements CompilationUnitTreeMatcher {
+  private static final long serialVersionUID = 1L;
+
+  /** Instantiates a new {@link SourceCodeAvailability} instance. */
+  public SourceCodeAvailability() {}
+
+  @Override
+  public Description matchCompilationUnit(CompilationUnitTree tree, VisitorState state) {
+    Deque<Boolean> seenAccurateSource = new ArrayDeque<>();
+    Set<Tree> maximalAccurateSubtrees = new LinkedHashSet<>();
+    new TreeScanner<@Nullable Void, TreePath>() {
+      @Override
+      public @Nullable Void scan(Tree node, TreePath treePath) {
+        if (node == null) {
+          return null;
+        }
+
+        TreePath path = new TreePath(treePath, node);
+        boolean isAccurate = SourceCode.isAccurateSourceLikelyAvailable(state.withPath(path));
+        if (!isAccurate) {
+          verify(!Boolean.TRUE.equals(seenAccurateSource.peek()));
+        } else if (!Boolean.TRUE.equals(seenAccurateSource.peek())) {
+          maximalAccurateSubtrees.add(node);
+        }
+
+        seenAccurateSource.push(isAccurate);
+        try {
+          return super.scan(node, path);
+        } finally {
+          seenAccurateSource.pop();
+        }
+      }
+    }.scan(tree, state.getPath());
+
+    if (maximalAccurateSubtrees.equals(ImmutableSet.of(tree))) {
+      return Description.NO_MATCH;
+    }
+
+    String accurateSubtrees =
+        maximalAccurateSubtrees.stream()
+            .map(
+                t ->
+                    String.format(
+                        "%s tree at position %s:\n%s",
+                        t.getKind(), ASTHelpers.getStartPosition(t), state.getSourceForNode(t)))
+            .collect(joining("\n\n", "Maximally accurate subtrees found:\n\n", ""));
+
+    return buildDescription(tree).setMessage(accurateSubtrees).build();
+  }
+}

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/StringCaseLocaleUsage.java

@@ -1,89 +0,0 @@
-package tech.picnic.errorprone.bugpatterns;
-
-import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
-import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
-import static com.google.errorprone.BugPattern.StandardTags.FRAGILE_CODE;
-import static com.google.errorprone.matchers.method.MethodMatchers.instanceMethod;
-import static com.sun.tools.javac.parser.Tokens.TokenKind.RPAREN;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
-
-import com.google.auto.service.AutoService;
-import com.google.common.collect.Streams;
-import com.google.errorprone.BugPattern;
-import com.google.errorprone.VisitorState;
-import com.google.errorprone.bugpatterns.BugChecker;
-import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
-import com.google.errorprone.fixes.Fix;
-import com.google.errorprone.fixes.SuggestedFix;
-import com.google.errorprone.matchers.Description;
-import com.google.errorprone.matchers.Matcher;
-import com.google.errorprone.util.ASTHelpers;
-import com.google.errorprone.util.ErrorProneTokens;
-import com.sun.source.tree.ExpressionTree;
-import com.sun.source.tree.MethodInvocationTree;
-import com.sun.tools.javac.util.Position;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
-
-/**
- * A {@link BugChecker} that flags calls to {@link String#toLowerCase()} and {@link
- * String#toUpperCase()}, as these methods implicitly rely on the environment's default locale.
- */
-// XXX: Also flag `String::toLowerCase` and `String::toUpperCase` method references. For these cases
-// the suggested fix should introduce a lambda expression with a parameter of which the name does
-// not coincide with the name of an existing variable name. Such functionality should likely be
-// introduced in a utility class.
-@AutoService(BugChecker.class)
-@BugPattern(
-    summary = "Specify a `Locale` when calling `String#to{Lower,Upper}Case`",
-    link = BUG_PATTERNS_BASE_URL + "StringCaseLocaleUsage",
-    linkType = CUSTOM,
-    severity = WARNING,
-    tags = FRAGILE_CODE)
-public final class StringCaseLocaleUsage extends BugChecker implements MethodInvocationTreeMatcher {
-  private static final long serialVersionUID = 1L;
-  private static final Matcher<ExpressionTree> DEFAULT_LOCALE_CASE_CONVERSION =
-      instanceMethod()
-          .onExactClass(String.class.getName())
-          .namedAnyOf("toLowerCase", "toUpperCase")
-          .withNoParameters();
-
-  /** Instantiates a new {@link StringCaseLocaleUsage} instance. */
-  public StringCaseLocaleUsage() {}
-
-  @Override
-  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
-    if (!DEFAULT_LOCALE_CASE_CONVERSION.matches(tree, state)) {
-      return Description.NO_MATCH;
-    }
-
-    int closingParenPosition = getClosingParenPosition(tree, state);
-    if (closingParenPosition == Position.NOPOS) {
-      return describeMatch(tree);
-    }
-
-    return buildDescription(tree)
-        .addFix(suggestLocale(closingParenPosition, "Locale.ROOT"))
-        .addFix(suggestLocale(closingParenPosition, "Locale.getDefault()"))
-        .build();
-  }
-
-  private static Fix suggestLocale(int insertPosition, String locale) {
-    return SuggestedFix.builder()
-        .addImport("java.util.Locale")
-        .replace(insertPosition, insertPosition, locale)
-        .build();
-  }
-
-  private static int getClosingParenPosition(MethodInvocationTree tree, VisitorState state) {
-    int startPosition = ASTHelpers.getStartPosition(tree);
-    if (startPosition == Position.NOPOS) {
-      return Position.NOPOS;
-    }
-
-    return Streams.findLast(
-            ErrorProneTokens.getTokens(SourceCode.treeToString(tree, state), state.context).stream()
-                .filter(t -> t.kind() == RPAREN))
-        .map(token -> startPosition + token.pos())
-        .orElse(Position.NOPOS);
-  }
-}

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/AnnotationAttributeMatcher.java

@@ -103,7 +103,7 @@ public final class AnnotationAttributeMatcher implements Serializable {
    * @param tree The annotation AST node to be inspected.
    * @return Any matching annotation arguments.
    */
-  public Stream<? extends ExpressionTree> extractMatchingArguments(AnnotationTree tree) {
+  public Stream<ExpressionTree> extractMatchingArguments(AnnotationTree tree) {
     Type type = ASTHelpers.getType(tree.getAnnotationType());
     if (type == null) {
       return Stream.empty();
@@ -111,6 +111,7 @@ public final class AnnotationAttributeMatcher implements Serializable {
 
     String annotationType = type.toString();
     return tree.getArguments().stream()
+        .map(ExpressionTree.class::cast)
         .filter(a -> matches(annotationType, extractAttributeName(a)));
   }
 

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/JavaKeywords.java

@@ -114,6 +114,7 @@ public final class JavaKeywords {
    * @see <a href="https://docs.oracle.com/javase/specs/jls/se17/html/jls-3.html#jls-3.8">JDK 17 JLS
    *     section 3.8: Identifiers</a>
    */
+  @SuppressWarnings("java:S1067" /* Chaining conjunctions like this does not impact readability. */)
   public static boolean isValidIdentifier(String str) {
     return !str.isEmpty()
         && !isReservedKeyword(str)

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/MethodMatcherFactory.java

@@ -18,6 +18,9 @@ import java.util.regex.Pattern;
 public final class MethodMatcherFactory {
   private static final Splitter ARGUMENT_TYPE_SPLITTER =
       Splitter.on(',').trimResults().omitEmptyStrings();
+  // XXX: Check whether we can use a parser for "standard" Java signatures here. Maybe
+  // `sun.reflect.generics.parser.SignatureParser`?
+  @SuppressWarnings("java:S5998" /* In practice there will be only modest recursion. */)
   private static final Pattern METHOD_SIGNATURE =
       Pattern.compile("([^\\s#(,)]+)#([^\\s#(,)]+)\\(((?:[^\\s#(,)]+(?:,[^\\s#(,)]+)*)?)\\)");
 

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/MoreASTHelpers.java

@@ -5,8 +5,12 @@ import static com.google.common.collect.ImmutableList.toImmutableList;
 
 import com.google.common.collect.ImmutableList;
 import com.google.errorprone.VisitorState;
+import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.ClassTree;
+import com.sun.source.tree.LambdaExpressionTree;
 import com.sun.source.tree.MethodTree;
+import com.sun.source.tree.Tree;
+import java.util.Optional;
 
 /**
  * A collection of helper methods for working with the AST.
@@ -46,4 +50,33 @@ public final class MoreASTHelpers {
   public static boolean methodExistsInEnclosingClass(CharSequence methodName, VisitorState state) {
     return !findMethods(methodName, state).isEmpty();
   }
+
+  /**
+   * Returns the {@link MethodTree} from which control flow would exit if there would be a {@code
+   * return} statement at the given {@link VisitorState}'s current {@link VisitorState#getPath()
+   * path}.
+   *
+   * @param state The {@link VisitorState} from which to derive the AST location of interest.
+   * @return A {@link MethodTree}, unless the {@link VisitorState}'s path does not point to an AST
+   *     node located inside a method, or if the (hypothetical) {@code return} statement would exit
+   *     a lambda expression instead.
+   */
+  public static Optional<MethodTree> findMethodExitedOnReturn(VisitorState state) {
+    return Optional.ofNullable(state.findEnclosing(LambdaExpressionTree.class, MethodTree.class))
+        .filter(MethodTree.class::isInstance)
+        .map(MethodTree.class::cast);
+  }
+
+  /**
+   * Tells whether the given trees are of the same type, after type erasure.
+   *
+   * @param treeA The first tree of interest.
+   * @param treeB The second tree of interest.
+   * @param state The {@link VisitorState} describing the context in which the given trees were
+   *     found.
+   * @return Whether the specified trees have the same erased types.
+   */
+  public static boolean areSameType(Tree treeA, Tree treeB, VisitorState state) {
+    return ASTHelpers.isSameType(ASTHelpers.getType(treeA), ASTHelpers.getType(treeB), state);
+  }
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/MoreJUnitMatchers.java

@@ -1,6 +1,6 @@
 package tech.picnic.errorprone.bugpatterns.util;
 
-import static com.google.common.collect.ImmutableSet.toImmutableSet;
+import static com.google.common.collect.ImmutableList.toImmutableList;
 import static com.google.errorprone.matchers.ChildMultiMatcher.MatchType.AT_LEAST_ONE;
 import static com.google.errorprone.matchers.Matchers.annotations;
 import static com.google.errorprone.matchers.Matchers.anyOf;
@@ -9,7 +9,7 @@ import static java.util.Objects.requireNonNullElse;
 import static tech.picnic.errorprone.bugpatterns.util.MoreMatchers.hasMetaAnnotation;
 
 import com.google.common.base.Strings;
-import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableList;
 import com.google.errorprone.matchers.AnnotationMatcherUtils;
 import com.google.errorprone.matchers.Matcher;
 import com.google.errorprone.matchers.MultiMatcher;
@@ -55,25 +55,59 @@ public final class MoreJUnitMatchers {
    * Returns the names of the JUnit value factory methods specified by the given {@link
    * org.junit.jupiter.params.provider.MethodSource} annotation.
    *
+   * <p>This method differs from {@link #getMethodSourceFactoryDescriptors(AnnotationTree,
+   * MethodTree)} in that it drops any parenthesized method parameter type enumerations. That is,
+   * method descriptors such as {@code factoryMethod()} and {@code factoryMethod(java.lang.String)}
+   * are both simplified to just {@code factoryMethod}. This also means that the returned method
+   * names may not unambiguously reference a single value factory method; in such a case JUnit will
+   * throw an error at runtime.
+   *
    * @param methodSourceAnnotation The annotation from which to extract value factory method names.
-   * @return One or more value factory names.
+   * @param method The method on which the annotation is located.
+   * @return One or more value factory descriptors, in the order defined.
+   * @see #getMethodSourceFactoryDescriptors(AnnotationTree, MethodTree)
    */
-  static ImmutableSet<String> getMethodSourceFactoryNames(
+  // XXX: Drop this method in favour of `#getMethodSourceFactoryDescriptors`. That will require
+  // callers to either explicitly drop information, or perform a more advanced analysis.
+  public static ImmutableList<String> getMethodSourceFactoryNames(
+      AnnotationTree methodSourceAnnotation, MethodTree method) {
+    return getMethodSourceFactoryDescriptors(methodSourceAnnotation, method).stream()
+        .map(
+            descriptor -> {
+              int index = descriptor.indexOf('(');
+              return index < 0 ? descriptor : descriptor.substring(0, index);
+            })
+        .collect(toImmutableList());
+  }
+
+  /**
+   * Returns the descriptors of the JUnit value factory methods specified by the given {@link
+   * org.junit.jupiter.params.provider.MethodSource} annotation.
+   *
+   * @param methodSourceAnnotation The annotation from which to extract value factory method
+   *     descriptors.
+   * @param method The method on which the annotation is located.
+   * @return One or more value factory descriptors, in the order defined.
+   * @see #getMethodSourceFactoryNames(AnnotationTree, MethodTree)
+   */
+  // XXX: Rather than strings, have this method return instances of a value type capable of
+  // resolving the value factory method pointed to.
+  public static ImmutableList<String> getMethodSourceFactoryDescriptors(
       AnnotationTree methodSourceAnnotation, MethodTree method) {
     String methodName = method.getName().toString();
     ExpressionTree value = AnnotationMatcherUtils.getArgument(methodSourceAnnotation, "value");
 
     if (!(value instanceof NewArrayTree)) {
-      return ImmutableSet.of(toMethodSourceFactoryName(value, methodName));
+      return ImmutableList.of(toMethodSourceFactoryDescriptor(value, methodName));
     }
 
     return ((NewArrayTree) value)
         .getInitializers().stream()
-            .map(name -> toMethodSourceFactoryName(name, methodName))
-            .collect(toImmutableSet());
+            .map(name -> toMethodSourceFactoryDescriptor(name, methodName))
+            .collect(toImmutableList());
   }
 
-  private static String toMethodSourceFactoryName(
+  private static String toMethodSourceFactoryDescriptor(
       @Nullable ExpressionTree tree, String annotatedMethodName) {
     return requireNonNullElse(
         Strings.emptyToNull(ASTHelpers.constValue(tree, String.class)), annotatedMethodName);

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/MoreMatchers.java

@@ -1,11 +1,14 @@
 package tech.picnic.errorprone.bugpatterns.util;
 
+import static com.google.errorprone.matchers.Matchers.typePredicateMatcher;
+import static tech.picnic.errorprone.bugpatterns.util.MoreTypePredicates.hasAnnotation;
+
 import com.google.errorprone.matchers.Matcher;
 import com.google.errorprone.matchers.Matchers;
-import com.google.errorprone.predicates.TypePredicate;
-import com.google.errorprone.util.ASTHelpers;
+import com.google.errorprone.suppliers.Supplier;
 import com.sun.source.tree.AnnotationTree;
-import com.sun.tools.javac.code.Symbol;
+import com.sun.source.tree.Tree;
+import com.sun.tools.javac.code.Type;
 
 /**
  * A collection of general-purpose {@link Matcher}s.
@@ -25,15 +28,21 @@ public final class MoreMatchers {
    * @return A {@link Matcher} that matches trees with the specified meta-annotation.
    */
   public static <T extends AnnotationTree> Matcher<T> hasMetaAnnotation(String annotationType) {
-    TypePredicate typePredicate = hasAnnotation(annotationType);
-    return (tree, state) -> {
-      Symbol sym = ASTHelpers.getSymbol(tree);
-      return sym != null && typePredicate.apply(sym.type, state);
-    };
+    return typePredicateMatcher(hasAnnotation(annotationType));
   }
 
-  // XXX: Consider moving to a `MoreTypePredicates` utility class.
-  private static TypePredicate hasAnnotation(String annotationClassName) {
-    return (type, state) -> ASTHelpers.hasAnnotation(type.tsym, annotationClassName, state);
+  /**
+   * Returns a {@link Matcher} that determines whether the type of a given {@link Tree} is a subtype
+   * of the type returned by the specified {@link Supplier}.
+   *
+   * <p>This method differs from {@link Matchers#isSubtypeOf(Supplier)} in that it does not perform
+   * type erasure.
+   *
+   * @param <T> The type of tree to match against.
+   * @param type The {@link Supplier} that returns the type to match against.
+   * @return A {@link Matcher} that matches trees with the specified type.
+   */
+  public static <T extends Tree> Matcher<T> isSubTypeOf(Supplier<Type> type) {
+    return typePredicateMatcher(MoreTypePredicates.isSubTypeOf(type));
   }
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/MoreTypePredicates.java

@@ -0,0 +1,63 @@
+package tech.picnic.errorprone.bugpatterns.util;
+
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.predicates.TypePredicate;
+import com.google.errorprone.predicates.TypePredicates;
+import com.google.errorprone.suppliers.Supplier;
+import com.google.errorprone.util.ASTHelpers;
+import com.sun.tools.javac.code.Type;
+import com.sun.tools.javac.util.List;
+
+/**
+ * A collection of general-purpose {@link TypePredicate}s.
+ *
+ * <p>These methods are additions to the ones found in {@link TypePredicates}.
+ */
+// XXX: The methods in this class are tested only indirectly. Consider adding a dedicated test
+// class, or make sure that each method is explicitly covered by a tested analog in `MoreMatchers`.
+public final class MoreTypePredicates {
+  private MoreTypePredicates() {}
+
+  /**
+   * Returns a {@link TypePredicate} that matches types that are annotated with the indicated
+   * annotation type.
+   *
+   * @param annotationType The fully-qualified name of the annotation type.
+   * @return A {@link TypePredicate} that matches appropriate types.
+   */
+  public static TypePredicate hasAnnotation(String annotationType) {
+    return (type, state) -> ASTHelpers.hasAnnotation(type.tsym, annotationType, state);
+  }
+
+  /**
+   * Returns a {@link TypePredicate} that matches subtypes of the type returned by the specified
+   * {@link Supplier}.
+   *
+   * @implNote This method does not use {@link ASTHelpers#isSubtype(Type, Type, VisitorState)}, as
+   *     that method performs type erasure.
+   * @param bound The {@link Supplier} that returns the type to match against.
+   * @return A {@link TypePredicate} that matches appropriate subtypes.
+   */
+  public static TypePredicate isSubTypeOf(Supplier<Type> bound) {
+    Supplier<Type> memoizedType = VisitorState.memoize(bound);
+    return (type, state) -> {
+      Type boundType = memoizedType.get(state);
+      return boundType != null && state.getTypes().isSubtype(type, boundType);
+    };
+  }
+
+  /**
+   * Returns a {@link TypePredicate} that matches generic types with a type parameter that matches
+   * the specified {@link TypePredicate} at the indicated index.
+   *
+   * @param index The index of the type parameter to match against.
+   * @param predicate The {@link TypePredicate} to match against the type parameter.
+   * @return A {@link TypePredicate} that matches appropriate generic types.
+   */
+  public static TypePredicate hasTypeParameter(int index, TypePredicate predicate) {
+    return (type, state) -> {
+      List<Type> typeArguments = type.getTypeArguments();
+      return typeArguments.size() > index && predicate.apply(typeArguments.get(index), state);
+    };
+  }
+}

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/SourceCode.java

@@ -1,12 +1,40 @@
 package tech.picnic.errorprone.bugpatterns.util;
 
-import static com.sun.tools.javac.util.Position.NOPOS;
+import static com.sun.source.tree.Tree.Kind.*;
+import static com.sun.tools.javac.parser.Tokens.TokenKind.RPAREN;
+import static java.util.stream.Collectors.joining;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.CharMatcher;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Range;
+import com.google.common.collect.Sets;
+import com.google.common.collect.Streams;
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.fixes.SuggestedFix;
+import com.google.errorprone.util.ASTHelpers;
+import com.google.errorprone.util.ErrorProneToken;
+import com.google.errorprone.util.ErrorProneTokens;
+import com.sun.source.tree.AnnotationTree;
+import com.sun.source.tree.AssignmentTree;
+import com.sun.source.tree.ExpressionStatementTree;
+import com.sun.source.tree.IdentifierTree;
+import com.sun.source.tree.MethodInvocationTree;
+import com.sun.source.tree.MethodTree;
+import com.sun.source.tree.ModifiersTree;
 import com.sun.source.tree.Tree;
+import com.sun.source.util.TreePath;
+import com.sun.source.util.TreeScanner;
+import com.sun.tools.javac.code.Kinds;
+import com.sun.tools.javac.code.Symbol;
 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
+import com.sun.tools.javac.util.Position;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.function.Predicate;
+import java.util.stream.Stream;
+import org.jspecify.annotations.Nullable;
 
 /**
  * A collection of Error Prone utility methods for dealing with the source code representation of
@@ -16,8 +44,136 @@ public final class SourceCode {
   /** The complement of {@link CharMatcher#whitespace()}. */
   private static final CharMatcher NON_WHITESPACE_MATCHER = CharMatcher.whitespace().negate();
 
+  // XXX: Document.
+  // XXX: Once we raise the baseline to JDK 17+, review whether `BINDING_PATTERN` and
+  // `GUARDED_PATTERN` should be added.
+  // XXX: Review which JDK >17 tree kinds should be added.
+  private static final ImmutableSet<Tree.Kind> TREE_KINDS_WITHOUT_EXPLICIT_SYNTAX =
+      Sets.immutableEnumSet(COMPILATION_UNIT, MODIFIERS, ERRONEOUS, OTHER);
+
   private SourceCode() {}
 
+  // XXX: Document that that the test is relative to the state's current path.
+  public static boolean isAccurateSourceLikelyAvailable(VisitorState state) {
+    return new IsAccurateSourceLikelyAvailable().test(state);
+  }
+
+  // XXX: Move this class down or to a separate file.
+  // XXX: Cache data in `VisitorState.config`.
+  private static final class IsAccurateSourceLikelyAvailable
+      extends TreeScanner<@Nullable Boolean, VisitorState> implements Predicate<VisitorState> {
+    @Override
+    public boolean test(VisitorState state) {
+      return isValidAncestorSourceContainment(state) && isValidDescendantSourceContainment(state);
+    }
+
+    @Override
+    public @Nullable Boolean scan(@Nullable Tree tree, VisitorState parentState) {
+      if (tree == null) {
+        return Boolean.TRUE;
+      }
+
+      VisitorState childState = parentState.withPath(new TreePath(parentState.getPath(), tree));
+      return isValidSourceContainment(childState) ? super.scan(tree, childState) : Boolean.FALSE;
+    }
+
+    @Override
+    public @Nullable Boolean reduce(@Nullable Boolean a, @Nullable Boolean b) {
+      return !(Boolean.FALSE.equals(a) || Boolean.FALSE.equals(b));
+    }
+
+    private boolean isValidDescendantSourceContainment(VisitorState state) {
+      return !Boolean.FALSE.equals(super.scan(state.getPath().getLeaf(), state));
+    }
+
+    private static boolean isValidAncestorSourceContainment(VisitorState state) {
+      return Stream.iterate(state.getPath(), Objects::nonNull, TreePath::getParentPath)
+          .allMatch(path -> isValidSourceContainment(state.withPath(path)));
+    }
+
+    private static boolean isValidSourceContainment(VisitorState state) {
+      Tree tree = state.getPath().getLeaf();
+      TreePath parentPath = state.getPath().getParentPath();
+      if (parentPath == null) {
+        return getSourceRange(tree, state) != null;
+      }
+
+      Tree enclosingTree = parentPath.getLeaf();
+      @Nullable Range<Integer> enclosingSourceRange = getSourceRange(enclosingTree, state);
+      @Nullable Range<Integer> sourceRange = getSourceRange(tree, state);
+      if (enclosingSourceRange == null) {
+        return sourceRange == null || mayBeImplicit(enclosingTree, state);
+        // XXX: Test code; drop.
+        //        return  sourceRange == null && mayBeImplicit(enclosingTree, state);
+        //        (sourceRange == null || mayBeImplicit(enclosingTree, state)) != (sourceRange ==
+        // null && mayBeImplicit(enclosingTree, state))
+      }
+
+      if (sourceRange == null) {
+        return mayBeImplicit(tree, state);
+      }
+
+      return enclosingSourceRange.encloses(sourceRange)
+          && (TREE_KINDS_WITHOUT_EXPLICIT_SYNTAX.contains(enclosingTree.getKind())
+              || !enclosingSourceRange.equals(sourceRange));
+    }
+
+    private static boolean mayBeImplicit(Tree tree, VisitorState state) {
+      if (tree instanceof ModifiersTree) {
+        ModifiersTree modifiers = (ModifiersTree) tree;
+        return modifiers.getAnnotations().isEmpty() && modifiers.getFlags().isEmpty();
+      }
+
+      // XXX: We could even *require* the generated constructor subtree to not have any associated
+      // source.
+      if (ASTHelpers.isGeneratedConstructor(state.findEnclosing(MethodTree.class))) {
+        return true;
+      }
+
+      AnnotationTree annotation = state.findEnclosing(AnnotationTree.class);
+      if (annotation != null && annotation.getArguments().size() == 1) {
+        // XXX: The `IdentifierTree` check here has no impact because its parent will in practice be
+        // `null`, which prevents `mayBeImplicit` being called review how we can be stricter.
+        Symbol symbol =
+            tree instanceof AssignmentTree
+                ? ASTHelpers.getSymbol(((AssignmentTree) tree).getVariable())
+                : tree instanceof IdentifierTree ? ASTHelpers.getSymbol(tree) : null;
+
+        /* The `value` attribute may be omitted from single-argument annotation declarations. */
+        return symbol != null
+            && symbol.kind == Kinds.Kind.MTH
+            && symbol.name.contentEquals("value");
+      }
+
+      // XXX: Many branches aren't covered yet.
+      return isSuperInvocation(tree)
+          || (tree instanceof IdentifierTree
+              && isSuperInvocation(state.getPath().getParentPath().getLeaf()));
+    }
+
+    private static boolean isSuperInvocation(Tree tree) {
+      if (tree instanceof ExpressionStatementTree) {
+        return isSuperInvocation(((ExpressionStatementTree) tree).getExpression());
+      }
+
+      if (!(tree instanceof MethodInvocationTree)) {
+        return false;
+      }
+
+      MethodInvocationTree invocation = (MethodInvocationTree) tree;
+      return invocation.getArguments().isEmpty()
+          && ASTHelpers.isSuper(invocation.getMethodSelect());
+    }
+
+    private static @Nullable Range<Integer> getSourceRange(Tree tree, VisitorState state) {
+      int startPosition = ASTHelpers.getStartPosition(tree);
+      int endPosition = state.getEndPosition(tree);
+      return startPosition == Position.NOPOS || endPosition == Position.NOPOS
+          ? null
+          : Range.closedOpen(startPosition, endPosition);
+    }
+  }
+
   /**
    * Returns a string representation of the given {@link Tree}, preferring the original source code
    * (if available) over its prettified representation.
@@ -48,7 +204,7 @@ public final class SourceCode {
   public static SuggestedFix deleteWithTrailingWhitespace(Tree tree, VisitorState state) {
     CharSequence sourceCode = state.getSourceCode();
     int endPos = state.getEndPosition(tree);
-    if (sourceCode == null || endPos == NOPOS) {
+    if (sourceCode == null || endPos == Position.NOPOS) {
       /* We can't identify the trailing whitespace; delete just the tree. */
       return SuggestedFix.delete(tree);
     }
@@ -59,4 +215,57 @@ public final class SourceCode {
         whitespaceEndPos == -1 ? sourceCode.length() : whitespaceEndPos,
         "");
   }
+
+  /**
+   * Creates a {@link SuggestedFix} for the replacement of the given {@link MethodInvocationTree}
+   * with just the arguments to the method invocation, effectively "unwrapping" the method
+   * invocation.
+   *
+   * <p>For example, given the method invocation {@code foo.bar(1, 2, 3)}, this method will return a
+   * {@link SuggestedFix} that replaces the method invocation with {@code 1, 2, 3}.
+   *
+   * <p>This method aims to preserve the original formatting of the method invocation, including
+   * whitespace and comments.
+   *
+   * @param tree The AST node to be unwrapped.
+   * @param state A {@link VisitorState} describing the context in which the given {@link
+   *     MethodInvocationTree} is found.
+   * @return A non-{@code null} {@link SuggestedFix}.
+   */
+  public static SuggestedFix unwrapMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+    CharSequence sourceCode = state.getSourceCode();
+    int startPosition = state.getEndPosition(tree.getMethodSelect());
+    int endPosition = state.getEndPosition(tree);
+
+    if (sourceCode == null || startPosition == Position.NOPOS || endPosition == Position.NOPOS) {
+      return unwrapMethodInvocationDroppingWhitespaceAndComments(tree, state);
+    }
+
+    ImmutableList<ErrorProneToken> tokens =
+        ErrorProneTokens.getTokens(
+            sourceCode.subSequence(startPosition, endPosition).toString(), state.context);
+
+    Optional<Integer> leftParenPosition =
+        tokens.stream().findFirst().map(t -> startPosition + t.endPos());
+    Optional<Integer> rightParenPosition =
+        Streams.findLast(tokens.stream().filter(t -> t.kind() == RPAREN))
+            .map(t -> startPosition + t.pos());
+    if (leftParenPosition.isEmpty() || rightParenPosition.isEmpty()) {
+      return unwrapMethodInvocationDroppingWhitespaceAndComments(tree, state);
+    }
+
+    return SuggestedFix.replace(
+        tree,
+        sourceCode
+            .subSequence(leftParenPosition.orElseThrow(), rightParenPosition.orElseThrow())
+            .toString());
+  }
+
+  @VisibleForTesting
+  static SuggestedFix unwrapMethodInvocationDroppingWhitespaceAndComments(
+      MethodInvocationTree tree, VisitorState state) {
+    return SuggestedFix.replace(
+        tree,
+        tree.getArguments().stream().map(arg -> treeToString(arg, state)).collect(joining(", ")));
+  }
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/ThirdPartyLibrary.java

@@ -4,7 +4,10 @@ import com.google.errorprone.VisitorState;
 import com.google.errorprone.bugpatterns.BugChecker;
 import com.google.errorprone.suppliers.Supplier;
 import com.sun.tools.javac.code.ClassFinder;
+import com.sun.tools.javac.code.Source;
 import com.sun.tools.javac.code.Symbol.CompletionFailure;
+import com.sun.tools.javac.code.Symbol.ModuleSymbol;
+import com.sun.tools.javac.code.Symtab;
 import com.sun.tools.javac.util.Name;
 
 /**
@@ -86,11 +89,19 @@ public enum ThirdPartyLibrary {
 
   private static boolean canLoadClass(String className, VisitorState state) {
     ClassFinder classFinder = ClassFinder.instance(state.context);
+    Symtab symtab = state.getSymtab();
+    // XXX: Drop support for targeting Java 8 once the oldest supported JDK drops such support.
+    ModuleSymbol module =
+        Source.instance(state.context).compareTo(Source.JDK9) < 0
+            ? symtab.noModule
+            : symtab.unnamedModule;
     Name binaryName = state.binaryNameFromClassname(className);
     try {
-      classFinder.loadClass(state.getSymtab().unnamedModule, binaryName);
+      classFinder.loadClass(module, binaryName);
       return true;
-    } catch (CompletionFailure e) {
+    } catch (
+        @SuppressWarnings("java:S1166" /* Not exceptional. */)
+        CompletionFailure e) {
       return false;
     }
   }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJMapRules.java

@@ -16,15 +16,18 @@ import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
 import com.google.errorprone.refaster.annotation.UseImportPolicy;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.Map;
+import java.util.Set;
 import java.util.TreeMap;
 import java.util.TreeSet;
 import org.assertj.core.api.AbstractAssert;
 import org.assertj.core.api.AbstractBooleanAssert;
+import org.assertj.core.api.AbstractCollectionAssert;
 import org.assertj.core.api.AbstractMapAssert;
 import org.assertj.core.api.MapAssert;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
@@ -220,6 +223,19 @@ final class AssertJMapRules {
     }
   }
 
+  static final class AssertThatMapContainsOnlyKeys<K, V> {
+    @BeforeTemplate
+    AbstractCollectionAssert<?, Collection<? extends K>, K, ?> before(Map<K, V> map, Set<K> keys) {
+      return assertThat(map.keySet()).hasSameElementsAs(keys);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    MapAssert<K, V> after(Map<K, V> map, Set<K> keys) {
+      return assertThat(map).containsOnlyKeys(keys);
+    }
+  }
+
   static final class AssertThatMapContainsValue<K, V> {
     @BeforeTemplate
     AbstractBooleanAssert<?> before(Map<K, V> map, V value) {

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJPrimitiveRules.java

@@ -23,6 +23,8 @@ final class AssertJPrimitiveRules {
     }
 
     @BeforeTemplate
+    @SuppressWarnings(
+        "java:S1244" /* The (in)equality checks are fragile, but may be seen in the wild. */)
     AbstractBooleanAssert<?> before(double actual, double expected) {
       return Refaster.anyOf(
           assertThat(actual == expected).isTrue(), assertThat(actual != expected).isFalse());
@@ -43,6 +45,8 @@ final class AssertJPrimitiveRules {
     }
 
     @BeforeTemplate
+    @SuppressWarnings(
+        "java:S1244" /* The (in)equality checks are fragile, but may be seen in the wild. */)
     AbstractBooleanAssert<?> before(double actual, double expected) {
       return Refaster.anyOf(
           assertThat(actual != expected).isTrue(), assertThat(actual == expected).isFalse());

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJRules.java

@@ -2024,8 +2024,8 @@ final class AssertJRules {
   ////////////////////////////////////////////////////////////////////////////
   // Above: Generated code.
 
-  ///////////////////////////////////////////////////////////////////////////////////////////////////////
-  ///////////////////////////////////////////////////////////////////////////////////////////////////////
+  ////////////////////////////////////////////////////////////////////////////
+  ////////////////////////////////////////////////////////////////////////////
   // Organize the code below.
 
   // XXX: Do the "single Comparable" match shown below.

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJStringRules.java

@@ -1,11 +1,16 @@
 package tech.picnic.errorprone.refasterrules;
 
 import static com.google.errorprone.refaster.ImportPolicy.STATIC_IMPORT_ALWAYS;
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.assertj.core.api.Assertions.assertThat;
 
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
 import com.google.errorprone.refaster.annotation.UseImportPolicy;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import org.assertj.core.api.AbstractAssert;
 import org.assertj.core.api.AbstractStringAssert;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
@@ -89,4 +94,30 @@ final class AssertJStringRules {
       return assertThat(string).doesNotMatch(regex);
     }
   }
+
+  static final class AssertThatPathContent {
+    @BeforeTemplate
+    AbstractStringAssert<?> before(Path path, Charset charset) throws IOException {
+      return assertThat(Files.readString(path, charset));
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    AbstractStringAssert<?> after(Path path, Charset charset) {
+      return assertThat(path).content(charset);
+    }
+  }
+
+  static final class AssertThatPathContentUtf8 {
+    @BeforeTemplate
+    AbstractStringAssert<?> before(Path path) throws IOException {
+      return assertThat(Files.readString(path));
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    AbstractStringAssert<?> after(Path path) {
+      return assertThat(path).content(UTF_8);
+    }
+  }
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJThrowingCallableRules.java

@@ -47,7 +47,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByIllegalArgumentExceptionHasMessage {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByIllegalArgumentException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByIllegalArgumentException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
       return assertThatIllegalArgumentException().isThrownBy(throwingCallable).withMessage(message);
     }
@@ -64,7 +64,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByIllegalArgumentExceptionHasMessageParameters {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByIllegalArgumentException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByIllegalArgumentException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(
         ThrowingCallable throwingCallable, String message, @Repeated Object parameters) {
       return assertThatIllegalArgumentException()
@@ -85,7 +85,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByIllegalArgumentExceptionHasMessageStartingWith {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByIllegalArgumentException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByIllegalArgumentException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
       return assertThatIllegalArgumentException()
           .isThrownBy(throwingCallable)
@@ -104,7 +104,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByIllegalArgumentExceptionHasMessageContaining {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByIllegalArgumentException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByIllegalArgumentException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
       return assertThatIllegalArgumentException()
           .isThrownBy(throwingCallable)
@@ -123,7 +123,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByIllegalArgumentExceptionHasMessageNotContainingAny {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByIllegalArgumentException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByIllegalArgumentException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(
         ThrowingCallable throwingCallable, @Repeated CharSequence values) {
       return assertThatIllegalArgumentException()
@@ -157,7 +157,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByIllegalStateExceptionHasMessage {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByIllegalStateException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByIllegalStateException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
       return assertThatIllegalStateException().isThrownBy(throwingCallable).withMessage(message);
     }
@@ -174,7 +174,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByIllegalStateExceptionHasMessageParameters {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByIllegalStateException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByIllegalStateException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(
         ThrowingCallable throwingCallable, String message, @Repeated Object parameters) {
       return assertThatIllegalStateException()
@@ -195,7 +195,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByIllegalStateExceptionHasMessageStartingWith {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByIllegalStateException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByIllegalStateException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
       return assertThatIllegalStateException()
           .isThrownBy(throwingCallable)
@@ -214,7 +214,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByIllegalStateExceptionHasMessageContaining {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByIllegalStateException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByIllegalStateException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
       return assertThatIllegalStateException()
           .isThrownBy(throwingCallable)
@@ -233,7 +233,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByIllegalStateExceptionHasMessageNotContaining {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByIllegalStateException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByIllegalStateException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
       return assertThatIllegalStateException()
           .isThrownBy(throwingCallable)
@@ -265,7 +265,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByNullPointerExceptionHasMessage {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByNullPointerException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByNullPointerException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
       return assertThatNullPointerException().isThrownBy(throwingCallable).withMessage(message);
     }
@@ -282,7 +282,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByNullPointerExceptionHasMessageParameters {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByNullPointerException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByNullPointerException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(
         ThrowingCallable throwingCallable, String message, @Repeated Object parameters) {
       return assertThatNullPointerException()
@@ -303,7 +303,7 @@ final class AssertJThrowingCallableRules {
   static final class AssertThatThrownByNullPointerExceptionHasMessageStartingWith {
     @BeforeTemplate
     @SuppressWarnings(
-        "AssertThatThrownByNullPointerException" /* Matches strictly more specific expressions. */)
+        "AssertThatThrownByNullPointerException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
       return assertThatNullPointerException()
           .isThrownBy(throwingCallable)
@@ -319,6 +319,44 @@ final class AssertJThrowingCallableRules {
     }
   }
 
+  static final class AssertThatThrownByNullPointerExceptionHasMessageContaining {
+    @BeforeTemplate
+    @SuppressWarnings(
+        "AssertThatThrownByNullPointerException" /* This is a more specific template. */)
+    AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
+      return assertThatNullPointerException()
+          .isThrownBy(throwingCallable)
+          .withMessageContaining(message);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    AbstractObjectAssert<?, ?> after(ThrowingCallable throwingCallable, String message) {
+      return assertThatThrownBy(throwingCallable)
+          .isInstanceOf(NullPointerException.class)
+          .hasMessageContaining(message);
+    }
+  }
+
+  static final class AssertThatThrownByNullPointerExceptionHasMessageNotContaining {
+    @BeforeTemplate
+    @SuppressWarnings(
+        "AssertThatThrownByNullPointerException" /* This is a more specific template. */)
+    AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
+      return assertThatNullPointerException()
+          .isThrownBy(throwingCallable)
+          .withMessageNotContaining(message);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    AbstractObjectAssert<?, ?> after(ThrowingCallable throwingCallable, String message) {
+      return assertThatThrownBy(throwingCallable)
+          .isInstanceOf(NullPointerException.class)
+          .hasMessageNotContaining(message);
+    }
+  }
+
   static final class AssertThatThrownByIOException {
     @BeforeTemplate
     AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable) {
@@ -334,8 +372,7 @@ final class AssertJThrowingCallableRules {
 
   static final class AssertThatThrownByIOExceptionHasMessage {
     @BeforeTemplate
-    @SuppressWarnings(
-        "AssertThatThrownByIOException" /* Matches strictly more specific expressions. */)
+    @SuppressWarnings("AssertThatThrownByIOException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
       return assertThatIOException().isThrownBy(throwingCallable).withMessage(message);
     }
@@ -351,8 +388,7 @@ final class AssertJThrowingCallableRules {
 
   static final class AssertThatThrownByIOExceptionHasMessageParameters {
     @BeforeTemplate
-    @SuppressWarnings(
-        "AssertThatThrownByIOException" /* Matches strictly more specific expressions. */)
+    @SuppressWarnings("AssertThatThrownByIOException" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(
         ThrowingCallable throwingCallable, String message, @Repeated Object parameters) {
       return assertThatIOException().isThrownBy(throwingCallable).withMessage(message, parameters);
@@ -368,6 +404,54 @@ final class AssertJThrowingCallableRules {
     }
   }
 
+  static final class AssertThatThrownByIOExceptionHasMessageStartingWith {
+    @BeforeTemplate
+    @SuppressWarnings("AssertThatThrownByIOException" /* This is a more specific template. */)
+    AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
+      return assertThatIOException().isThrownBy(throwingCallable).withMessageStartingWith(message);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    AbstractObjectAssert<?, ?> after(ThrowingCallable throwingCallable, String message) {
+      return assertThatThrownBy(throwingCallable)
+          .isInstanceOf(IOException.class)
+          .hasMessageStartingWith(message);
+    }
+  }
+
+  static final class AssertThatThrownByIOExceptionHasMessageContaining {
+    @BeforeTemplate
+    @SuppressWarnings("AssertThatThrownByIOException" /* This is a more specific template. */)
+    AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
+      return assertThatIOException().isThrownBy(throwingCallable).withMessageContaining(message);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    AbstractObjectAssert<?, ?> after(ThrowingCallable throwingCallable, String message) {
+      return assertThatThrownBy(throwingCallable)
+          .isInstanceOf(IOException.class)
+          .hasMessageContaining(message);
+    }
+  }
+
+  static final class AssertThatThrownByIOExceptionHasMessageNotContaining {
+    @BeforeTemplate
+    @SuppressWarnings("AssertThatThrownByIOException" /* This is a more specific template. */)
+    AbstractObjectAssert<?, ?> before(ThrowingCallable throwingCallable, String message) {
+      return assertThatIOException().isThrownBy(throwingCallable).withMessageNotContaining(message);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    AbstractObjectAssert<?, ?> after(ThrowingCallable throwingCallable, String message) {
+      return assertThatThrownBy(throwingCallable)
+          .isInstanceOf(IOException.class)
+          .hasMessageNotContaining(message);
+    }
+  }
+
   static final class AssertThatThrownBy {
     @BeforeTemplate
     AbstractObjectAssert<?, ?> before(
@@ -385,7 +469,7 @@ final class AssertJThrowingCallableRules {
 
   static final class AssertThatThrownByHasMessage {
     @BeforeTemplate
-    @SuppressWarnings("AssertThatThrownBy" /* Matches strictly more specific expressions. */)
+    @SuppressWarnings("AssertThatThrownBy" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(
         Class<? extends Throwable> exceptionType,
         ThrowingCallable throwingCallable,
@@ -407,7 +491,7 @@ final class AssertJThrowingCallableRules {
 
   static final class AssertThatThrownByHasMessageParameters {
     @BeforeTemplate
-    @SuppressWarnings("AssertThatThrownBy" /* Matches strictly more specific expressions. */)
+    @SuppressWarnings("AssertThatThrownBy" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(
         Class<? extends Throwable> exceptionType,
         ThrowingCallable throwingCallable,
@@ -431,6 +515,78 @@ final class AssertJThrowingCallableRules {
     }
   }
 
+  static final class AssertThatThrownByHasMessageStartingWith {
+    @BeforeTemplate
+    @SuppressWarnings("AssertThatThrownBy" /* This is a more specific template. */)
+    AbstractObjectAssert<?, ?> before(
+        Class<? extends Throwable> exceptionType,
+        ThrowingCallable throwingCallable,
+        String message) {
+      return assertThatExceptionOfType(exceptionType)
+          .isThrownBy(throwingCallable)
+          .withMessageStartingWith(message);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    AbstractObjectAssert<?, ?> after(
+        Class<? extends Throwable> exceptionType,
+        ThrowingCallable throwingCallable,
+        String message) {
+      return assertThatThrownBy(throwingCallable)
+          .isInstanceOf(exceptionType)
+          .hasMessageStartingWith(message);
+    }
+  }
+
+  static final class AssertThatThrownByHasMessageContaining {
+    @BeforeTemplate
+    @SuppressWarnings("AssertThatThrownBy" /* This is a more specific template. */)
+    AbstractObjectAssert<?, ?> before(
+        Class<? extends Throwable> exceptionType,
+        ThrowingCallable throwingCallable,
+        String message) {
+      return assertThatExceptionOfType(exceptionType)
+          .isThrownBy(throwingCallable)
+          .withMessageContaining(message);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    AbstractObjectAssert<?, ?> after(
+        Class<? extends Throwable> exceptionType,
+        ThrowingCallable throwingCallable,
+        String message) {
+      return assertThatThrownBy(throwingCallable)
+          .isInstanceOf(exceptionType)
+          .hasMessageContaining(message);
+    }
+  }
+
+  static final class AssertThatThrownByHasMessageNotContaining {
+    @BeforeTemplate
+    @SuppressWarnings("AssertThatThrownBy" /* This is a more specific template. */)
+    AbstractObjectAssert<?, ?> before(
+        Class<? extends Throwable> exceptionType,
+        ThrowingCallable throwingCallable,
+        String message) {
+      return assertThatExceptionOfType(exceptionType)
+          .isThrownBy(throwingCallable)
+          .withMessageNotContaining(message);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    AbstractObjectAssert<?, ?> after(
+        Class<? extends Throwable> exceptionType,
+        ThrowingCallable throwingCallable,
+        String message) {
+      return assertThatThrownBy(throwingCallable)
+          .isInstanceOf(exceptionType)
+          .hasMessageNotContaining(message);
+    }
+  }
+
   // XXX: Drop this rule in favour of a generic Error Prone check that flags `String.format(...)`
   // arguments to a wide range of format methods.
   static final class AbstractThrowableAssertHasMessage {

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssortedRules.java

@@ -115,6 +115,7 @@ final class AssortedRules {
   // intelligently.
   static final class LogicalImplication {
     @BeforeTemplate
+    @SuppressWarnings("java:S2589" /* This violation will be rewritten. */)
     boolean before(boolean firstTest, boolean secondTest) {
       return firstTest || (!firstTest && secondTest);
     }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/BigDecimalRules.java

@@ -56,6 +56,7 @@ final class BigDecimalRules {
   // `BugChecker`.
   static final class BigDecimalValueOf {
     @BeforeTemplate
+    @SuppressWarnings("java:S2111" /* This violation will be rewritten. */)
     BigDecimal before(double value) {
       return new BigDecimal(value);
     }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/BugCheckerRules.java

@@ -0,0 +1,55 @@
+package tech.picnic.errorprone.refasterrules;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.FixChooser;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.FixChoosers;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
+import com.google.errorprone.refaster.Refaster;
+import com.google.errorprone.refaster.annotation.AfterTemplate;
+import com.google.errorprone.refaster.annotation.BeforeTemplate;
+import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
+
+/** Refaster rules related to {@link com.google.errorprone.bugpatterns.BugChecker} classes. */
+@OnlineDocumentation
+final class BugCheckerRules {
+  private BugCheckerRules() {}
+
+  /**
+   * Avoid calling {@link BugCheckerRefactoringTestHelper#setFixChooser(FixChooser)} or {@link
+   * BugCheckerRefactoringTestHelper#setImportOrder(String)} with their respective default values.
+   */
+  static final class BugCheckerRefactoringTestHelperIdentity {
+    @BeforeTemplate
+    BugCheckerRefactoringTestHelper before(BugCheckerRefactoringTestHelper helper) {
+      return Refaster.anyOf(
+          helper.setFixChooser(FixChoosers.FIRST), helper.setImportOrder("static-first"));
+    }
+
+    @AfterTemplate
+    @CanIgnoreReturnValue
+    BugCheckerRefactoringTestHelper after(BugCheckerRefactoringTestHelper helper) {
+      return helper;
+    }
+  }
+
+  /**
+   * Prefer {@link BugCheckerRefactoringTestHelper.ExpectOutput#expectUnchanged()} over repeating
+   * the input.
+   */
+  // XXX: This rule assumes that the full source code is specified as a single string, e.g. using a
+  // text block. Support for multi-line source code input would require a `BugChecker`
+  // implementation instead.
+  static final class BugCheckerRefactoringTestHelperAddInputLinesExpectUnchanged {
+    @BeforeTemplate
+    BugCheckerRefactoringTestHelper before(
+        BugCheckerRefactoringTestHelper helper, String path, String source) {
+      return helper.addInputLines(path, source).addOutputLines(path, source);
+    }
+
+    @AfterTemplate
+    BugCheckerRefactoringTestHelper after(
+        BugCheckerRefactoringTestHelper helper, String path, String source) {
+      return helper.addInputLines(path, source).expectUnchanged();
+    }
+  }
+}

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/CollectionRules.java

@@ -35,6 +35,7 @@ final class CollectionRules {
    */
   static final class CollectionIsEmpty<T> {
     @BeforeTemplate
+    @SuppressWarnings("java:S1155" /* This violation will be rewritten. */)
     boolean before(Collection<T> collection) {
       return Refaster.anyOf(
           collection.size() == 0,
@@ -73,6 +74,19 @@ final class CollectionRules {
     }
   }
 
+  /** Prefer {@link Collection#contains(Object)} over more contrived alternatives. */
+  static final class CollectionContains<T, S> {
+    @BeforeTemplate
+    boolean before(Collection<T> collection, S value) {
+      return collection.stream().anyMatch(value::equals);
+    }
+
+    @AfterTemplate
+    boolean after(Collection<T> collection, S value) {
+      return collection.contains(value);
+    }
+  }
+
   /**
    * Don't call {@link Iterables#addAll(Collection, Iterable)} when the elements to be added are
    * already part of a {@link Collection}.
@@ -163,6 +177,8 @@ final class CollectionRules {
   }
 
   /** Prefer {@link ArrayList#ArrayList(Collection)} over the Guava alternative. */
+  @SuppressWarnings(
+      "NonApiType" /* Matching against `List` would unnecessarily constrain the rule. */)
   static final class NewArrayListFromCollection<T> {
     @BeforeTemplate
     ArrayList<T> before(Collection<T> collection) {

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ComparatorRules.java

@@ -12,6 +12,7 @@ import static java.util.function.Function.identity;
 import com.google.common.collect.Comparators;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.refaster.Refaster;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
@@ -78,6 +79,7 @@ final class ComparatorRules {
     }
 
     @AfterTemplate
+    @CanIgnoreReturnValue
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     Comparator<T> after(Comparator<T> cmp) {
       return cmp;
@@ -219,7 +221,6 @@ final class ComparatorRules {
    */
   static final class MinOfVarargs<T> {
     @BeforeTemplate
-    @SuppressWarnings("StreamOfArray" /* In practice individual values are provided. */)
     T before(@Repeated T value, Comparator<T> cmp) {
       return Stream.of(Refaster.asVarargs(value)).min(cmp).orElseThrow();
     }
@@ -233,6 +234,7 @@ final class ComparatorRules {
   /** Prefer {@link Comparators#min(Comparable, Comparable)}} over more verbose alternatives. */
   static final class MinOfPairNaturalOrder<T extends Comparable<? super T>> {
     @BeforeTemplate
+    @SuppressWarnings("java:S1067" /* The conditional operators are independent. */)
     T before(T value1, T value2) {
       return Refaster.anyOf(
           value1.compareTo(value2) <= 0 ? value1 : value2,
@@ -259,6 +261,7 @@ final class ComparatorRules {
    */
   static final class MinOfPairCustomOrder<T> {
     @BeforeTemplate
+    @SuppressWarnings("java:S1067" /* The conditional operators are independent. */)
     T before(T value1, T value2, Comparator<T> cmp) {
       return Refaster.anyOf(
           cmp.compare(value1, value2) <= 0 ? value1 : value2,
@@ -285,7 +288,6 @@ final class ComparatorRules {
    */
   static final class MaxOfVarargs<T> {
     @BeforeTemplate
-    @SuppressWarnings("StreamOfArray" /* In practice individual values are provided. */)
     T before(@Repeated T value, Comparator<T> cmp) {
       return Stream.of(Refaster.asVarargs(value)).max(cmp).orElseThrow();
     }
@@ -299,6 +301,7 @@ final class ComparatorRules {
   /** Prefer {@link Comparators#max(Comparable, Comparable)}} over more verbose alternatives. */
   static final class MaxOfPairNaturalOrder<T extends Comparable<? super T>> {
     @BeforeTemplate
+    @SuppressWarnings("java:S1067" /* The conditional operators are independent. */)
     T before(T value1, T value2) {
       return Refaster.anyOf(
           value1.compareTo(value2) >= 0 ? value1 : value2,
@@ -325,6 +328,7 @@ final class ComparatorRules {
    */
   static final class MaxOfPairCustomOrder<T> {
     @BeforeTemplate
+    @SuppressWarnings("java:S1067" /* The conditional operators are independent. */)
     T before(T value1, T value2, Comparator<T> cmp) {
       return Refaster.anyOf(
           cmp.compare(value1, value2) >= 0 ? value1 : value2,

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/DoubleStreamRules.java

@@ -1,6 +1,7 @@
 package tech.picnic.errorprone.refasterrules;
 
 import com.google.common.collect.Streams;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.refaster.Refaster;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
@@ -27,6 +28,7 @@ final class DoubleStreamRules {
     }
 
     @AfterTemplate
+    @CanIgnoreReturnValue
     DoubleStream after(DoubleStream stream) {
       return stream;
     }
@@ -237,6 +239,7 @@ final class DoubleStreamRules {
   /** Prefer {@link DoubleStream#anyMatch(DoublePredicate)} over more contrived alternatives. */
   static final class DoubleStreamAnyMatch {
     @BeforeTemplate
+    @SuppressWarnings("java:S4034" /* This violation will be rewritten. */)
     boolean before(DoubleStream stream, DoublePredicate predicate) {
       return Refaster.anyOf(
           !stream.noneMatch(predicate), stream.filter(predicate).findAny().isPresent());
@@ -274,4 +277,16 @@ final class DoubleStreamRules {
       return stream.allMatch(e -> test(e));
     }
   }
+
+  static final class DoubleStreamTakeWhile {
+    @BeforeTemplate
+    DoubleStream before(DoubleStream stream, DoublePredicate predicate) {
+      return stream.takeWhile(predicate).filter(predicate);
+    }
+
+    @AfterTemplate
+    DoubleStream after(DoubleStream stream, DoublePredicate predicate) {
+      return stream.takeWhile(predicate);
+    }
+  }
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/EqualityRules.java

@@ -1,10 +1,16 @@
 package tech.picnic.errorprone.refasterrules;
 
+import static java.util.function.Predicate.not;
+
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.refaster.Refaster;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.AlsoNegation;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
+import com.google.errorprone.refaster.annotation.MayOptionallyUse;
+import com.google.errorprone.refaster.annotation.Placeholder;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Predicate;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 
@@ -30,6 +36,7 @@ final class EqualityRules {
 
     @AfterTemplate
     @AlsoNegation
+    @SuppressWarnings("java:S1698" /* Reference comparison is valid for enums. */)
     boolean after(T a, T b) {
       return a == b;
     }
@@ -56,11 +63,13 @@ final class EqualityRules {
   /** Avoid double negations; this is not Javascript. */
   static final class DoubleNegation {
     @BeforeTemplate
+    @SuppressWarnings("java:S2761" /* This violation will be rewritten. */)
     boolean before(boolean b) {
       return !!b;
     }
 
     @AfterTemplate
+    @CanIgnoreReturnValue
     boolean after(boolean b) {
       return b;
     }
@@ -72,6 +81,7 @@ final class EqualityRules {
    */
   // XXX: Replacing `a ? !b : b` with `a != b` changes semantics if both `a` and `b` are boxed
   // booleans.
+  @SuppressWarnings("java:S1940" /* This violation will be rewritten. */)
   static final class Negation {
     @BeforeTemplate
     boolean before(boolean a, boolean b) {
@@ -79,6 +89,8 @@ final class EqualityRules {
     }
 
     @BeforeTemplate
+    @SuppressWarnings(
+        "java:S1244" /* The equality check is fragile, but may be seen in the wild. */)
     boolean before(double a, double b) {
       return !(a == b);
     }
@@ -100,6 +112,7 @@ final class EqualityRules {
    */
   // XXX: Replacing `a ? b : !b` with `a == b` changes semantics if both `a` and `b` are boxed
   // booleans.
+  @SuppressWarnings("java:S1940" /* This violation will be rewritten. */)
   static final class IndirectDoubleNegation {
     @BeforeTemplate
     boolean before(boolean a, boolean b) {
@@ -107,6 +120,8 @@ final class EqualityRules {
     }
 
     @BeforeTemplate
+    @SuppressWarnings(
+        "java:S1244" /* The inequality check is fragile, but may be seen in the wild. */)
     boolean before(double a, double b) {
       return !(a != b);
     }
@@ -121,4 +136,62 @@ final class EqualityRules {
       return a == b;
     }
   }
+
+  /**
+   * Don't pass a lambda expression to {@link Predicate#not(Predicate)}; instead push the negation
+   * into the lambda expression.
+   */
+  abstract static class PredicateLambda<T> {
+    @Placeholder(allowsIdentity = true)
+    abstract boolean predicate(@MayOptionallyUse T value);
+
+    @BeforeTemplate
+    Predicate<T> before() {
+      return not(v -> predicate(v));
+    }
+
+    @AfterTemplate
+    Predicate<T> after() {
+      return v -> !predicate(v);
+    }
+  }
+
+  /** Avoid contrived ways of handling {@code null} values during equality testing. */
+  static final class EqualsLhsNullable<T, S> {
+    @BeforeTemplate
+    boolean before(T value1, S value2) {
+      return Optional.ofNullable(value1).equals(Optional.of(value2));
+    }
+
+    @AfterTemplate
+    boolean after(T value1, S value2) {
+      return value2.equals(value1);
+    }
+  }
+
+  /** Avoid contrived ways of handling {@code null} values during equality testing. */
+  static final class EqualsRhsNullable<T, S> {
+    @BeforeTemplate
+    boolean before(T value1, S value2) {
+      return Optional.of(value1).equals(Optional.ofNullable(value2));
+    }
+
+    @AfterTemplate
+    boolean after(T value1, S value2) {
+      return value1.equals(value2);
+    }
+  }
+
+  /** Avoid contrived ways of handling {@code null} values during equality testing. */
+  static final class EqualsLhsAndRhsNullable<T, S> {
+    @BeforeTemplate
+    boolean before(T value1, S value2) {
+      return Optional.ofNullable(value1).equals(Optional.ofNullable(value2));
+    }
+
+    @AfterTemplate
+    boolean after(T value1, S value2) {
+      return Objects.equals(value1, value2);
+    }
+  }
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/FileRules.java

@@ -0,0 +1,43 @@
+package tech.picnic.errorprone.refasterrules;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import com.google.errorprone.refaster.annotation.AfterTemplate;
+import com.google.errorprone.refaster.annotation.BeforeTemplate;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
+
+/** Refaster rules related to expressions dealing with files. */
+@OnlineDocumentation
+final class FileRules {
+  private FileRules() {}
+
+  /** Prefer {@link Files#readString(Path, Charset)} over more contrived alternatives. */
+  static final class FilesReadStringWithCharset {
+    @BeforeTemplate
+    String before(Path path, Charset charset) throws IOException {
+      return new String(Files.readAllBytes(path), charset);
+    }
+
+    @AfterTemplate
+    String after(Path path, Charset charset) throws IOException {
+      return Files.readString(path, charset);
+    }
+  }
+
+  /** Prefer {@link Files#readString(Path)} over more verbose alternatives. */
+  static final class FilesReadString {
+    @BeforeTemplate
+    String before(Path path) throws IOException {
+      return Files.readString(path, UTF_8);
+    }
+
+    @AfterTemplate
+    String after(Path path) throws IOException {
+      return Files.readString(path);
+    }
+  }
+}

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ImmutableMapRules.java

@@ -6,6 +6,7 @@ import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonMap;
 import static java.util.function.Function.identity;
 
+import com.google.common.base.Predicate;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Streams;
@@ -126,8 +127,8 @@ final class ImmutableMapRules {
   }
 
   /**
-   * Don't map a a stream's elements to map entries, only to subsequently collect them into an
-   * {@link ImmutableMap}. The collection can be performed directly.
+   * Don't map a stream's elements to map entries, only to subsequently collect them into an {@link
+   * ImmutableMap}. The collection can be performed directly.
    */
   abstract static class StreamOfMapEntriesToImmutableMap<E, K, V> {
     @Placeholder(allowsIdentity = true)
@@ -249,7 +250,8 @@ final class ImmutableMapRules {
    * Prefer {@link ImmutableMap#of(Object, Object, Object, Object)} over alternatives that don't
    * communicate the immutability of the resulting map at the type level.
    */
-  // XXX: Also rewrite the `ImmutableMap.builder()` variant?
+  // XXX: Consider introducing a `BugChecker` to replace these `ImmutableMapOfX` rules. That will
+  // also make it easier to rewrite various `ImmutableMap.builder()` variants.
   static final class ImmutableMapOf2<K, V> {
     @BeforeTemplate
     Map<K, V> before(K k1, V v1, K k2, V v2) {
@@ -266,7 +268,8 @@ final class ImmutableMapRules {
    * Prefer {@link ImmutableMap#of(Object, Object, Object, Object, Object, Object)} over
    * alternatives that don't communicate the immutability of the resulting map at the type level.
    */
-  // XXX: Also rewrite the `ImmutableMap.builder()` variant?
+  // XXX: Consider introducing a `BugChecker` to replace these `ImmutableMapOfX` rules. That will
+  // also make it easier to rewrite various `ImmutableMap.builder()` variants.
   static final class ImmutableMapOf3<K, V> {
     @BeforeTemplate
     Map<K, V> before(K k1, V v1, K k2, V v2, K k3, V v3) {
@@ -284,7 +287,9 @@ final class ImmutableMapRules {
    * over alternatives that don't communicate the immutability of the resulting map at the type
    * level.
    */
-  // XXX: Also rewrite the `ImmutableMap.builder()` variant?
+  // XXX: Consider introducing a `BugChecker` to replace these `ImmutableMapOfX` rules. That will
+  // also make it easier to rewrite various `ImmutableMap.builder()` variants.
+  @SuppressWarnings("java:S107" /* Can't avoid many method parameters here. */)
   static final class ImmutableMapOf4<K, V> {
     @BeforeTemplate
     Map<K, V> before(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
@@ -302,7 +307,9 @@ final class ImmutableMapRules {
    * Object, Object)} over alternatives that don't communicate the immutability of the resulting map
    * at the type level.
    */
-  // XXX: Also rewrite the `ImmutableMap.builder()` variant?
+  // XXX: Consider introducing a `BugChecker` to replace these `ImmutableMapOfX` rules. That will
+  // also make it easier to rewrite various `ImmutableMap.builder()` variants.
+  @SuppressWarnings("java:S107" /* Can't avoid many method parameters here. */)
   static final class ImmutableMapOf5<K, V> {
     @BeforeTemplate
     Map<K, V> before(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
@@ -315,6 +322,48 @@ final class ImmutableMapRules {
     }
   }
 
+  /**
+   * Prefer creation of an immutable submap using {@link Maps#filterKeys(Map, Predicate)} over more
+   * contrived alternatives.
+   */
+  abstract static class ImmutableMapCopyOfMapsFilterKeys<K, V> {
+    @Placeholder(allowsIdentity = true)
+    abstract boolean keyFilter(@MayOptionallyUse K key);
+
+    @BeforeTemplate
+    ImmutableMap<K, V> before(ImmutableMap<K, V> map) {
+      return map.entrySet().stream()
+          .filter(e -> keyFilter(e.getKey()))
+          .collect(toImmutableMap(Map.Entry::getKey, Map.Entry::getValue));
+    }
+
+    @AfterTemplate
+    ImmutableMap<K, V> after(ImmutableMap<K, V> map) {
+      return ImmutableMap.copyOf(Maps.filterKeys(map, k -> keyFilter(k)));
+    }
+  }
+
+  /**
+   * Prefer creation of an immutable submap using {@link Maps#filterValues(Map, Predicate)} over
+   * more contrived alternatives.
+   */
+  abstract static class ImmutableMapCopyOfMapsFilterValues<K, V> {
+    @Placeholder(allowsIdentity = true)
+    abstract boolean valueFilter(@MayOptionallyUse V value);
+
+    @BeforeTemplate
+    ImmutableMap<K, V> before(ImmutableMap<K, V> map) {
+      return map.entrySet().stream()
+          .filter(e -> valueFilter(e.getValue()))
+          .collect(toImmutableMap(Map.Entry::getKey, Map.Entry::getValue));
+    }
+
+    @AfterTemplate
+    ImmutableMap<K, V> after(ImmutableMap<K, V> map) {
+      return ImmutableMap.copyOf(Maps.filterValues(map, v -> valueFilter(v)));
+    }
+  }
+
   // XXX: Add a rule for this:
   // Maps.transformValues(streamOfEntries.collect(groupBy(fun)), ImmutableMap::copyOf)
   // ->
@@ -323,9 +372,4 @@ final class ImmutableMapRules {
   // map.entrySet().stream().filter(keyPred).forEach(mapBuilder::put)
   // ->
   // mapBuilder.putAll(Maps.filterKeys(map, pred))
-  //
-  // map.entrySet().stream().filter(entry ->
-  // pred(entry.getKey())).collect(toImmutableMap(Map.Entry::getKey, Map.Entry::getValue))
-  // ->
-  // ImmutableMap.copyOf(Maps.filterKeys(map, pred))
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ImmutableSetRules.java

@@ -4,8 +4,11 @@ import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static com.google.errorprone.refaster.ImportPolicy.STATIC_IMPORT_ALWAYS;
 import static java.util.Collections.emptySet;
 import static java.util.Collections.singleton;
+import static java.util.function.Predicate.not;
 
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.Sets;
 import com.google.common.collect.Sets.SetView;
 import com.google.common.collect.Streams;
 import com.google.errorprone.refaster.Refaster;
@@ -15,6 +18,7 @@ import com.google.errorprone.refaster.annotation.UseImportPolicy;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Iterator;
+import java.util.Map;
 import java.util.Set;
 import java.util.stream.Stream;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
@@ -211,4 +215,116 @@ final class ImmutableSetRules {
       return ImmutableSet.of(e1, e2, e3, e4, e5);
     }
   }
+
+  /**
+   * Prefer an immutable copy of {@link Sets#difference(Set, Set)} over more contrived alternatives.
+   */
+  static final class SetsDifference<S, T> {
+    @BeforeTemplate
+    ImmutableSet<S> before(Set<S> set1, Set<T> set2) {
+      return set1.stream()
+          .filter(Refaster.anyOf(not(set2::contains), e -> !set2.contains(e)))
+          .collect(toImmutableSet());
+    }
+
+    @AfterTemplate
+    ImmutableSet<S> after(Set<S> set1, Set<T> set2) {
+      return Sets.difference(set1, set2).immutableCopy();
+    }
+  }
+
+  /**
+   * Prefer an immutable copy of {@link Sets#difference(Set, Set)} over more contrived alternatives.
+   */
+  static final class SetsDifferenceMap<T, K, V> {
+    @BeforeTemplate
+    ImmutableSet<T> before(Set<T> set, Map<K, V> map) {
+      return set.stream()
+          .filter(Refaster.anyOf(not(map::containsKey), e -> !map.containsKey(e)))
+          .collect(toImmutableSet());
+    }
+
+    @AfterTemplate
+    ImmutableSet<K> after(Set<K> set, Map<K, V> map) {
+      return Sets.difference(set, map.keySet()).immutableCopy();
+    }
+  }
+
+  /**
+   * Prefer an immutable copy of {@link Sets#difference(Set, Set)} over more contrived alternatives.
+   */
+  static final class SetsDifferenceMultimap<T, K, V> {
+    @BeforeTemplate
+    ImmutableSet<T> before(Set<T> set, Multimap<K, V> multimap) {
+      return set.stream()
+          .filter(Refaster.anyOf(not(multimap::containsKey), e -> !multimap.containsKey(e)))
+          .collect(toImmutableSet());
+    }
+
+    @AfterTemplate
+    ImmutableSet<T> after(Set<T> set, Multimap<K, V> multimap) {
+      return Sets.difference(set, multimap.keySet()).immutableCopy();
+    }
+  }
+
+  /**
+   * Prefer an immutable copy of {@link Sets#intersection(Set, Set)} over more contrived
+   * alternatives.
+   */
+  static final class SetsIntersection<S, T> {
+    @BeforeTemplate
+    ImmutableSet<S> before(Set<S> set1, Set<T> set2) {
+      return set1.stream().filter(set2::contains).collect(toImmutableSet());
+    }
+
+    @AfterTemplate
+    ImmutableSet<S> after(Set<S> set1, Set<T> set2) {
+      return Sets.intersection(set1, set2).immutableCopy();
+    }
+  }
+
+  /**
+   * Prefer an immutable copy of {@link Sets#intersection(Set, Set)} over more contrived
+   * alternatives.
+   */
+  static final class SetsIntersectionMap<T, K, V> {
+    @BeforeTemplate
+    ImmutableSet<T> before(Set<T> set, Map<K, V> map) {
+      return set.stream().filter(map::containsKey).collect(toImmutableSet());
+    }
+
+    @AfterTemplate
+    ImmutableSet<T> after(Set<T> set, Map<K, V> map) {
+      return Sets.intersection(set, map.keySet()).immutableCopy();
+    }
+  }
+
+  /**
+   * Prefer an immutable copy of {@link Sets#intersection(Set, Set)} over more contrived
+   * alternatives.
+   */
+  static final class SetsIntersectionMultimap<T, K, V> {
+    @BeforeTemplate
+    ImmutableSet<T> before(Set<T> set, Multimap<K, V> multimap) {
+      return set.stream().filter(multimap::containsKey).collect(toImmutableSet());
+    }
+
+    @AfterTemplate
+    ImmutableSet<T> after(Set<T> set, Multimap<K, V> multimap) {
+      return Sets.intersection(set, multimap.keySet()).immutableCopy();
+    }
+  }
+
+  /** Prefer an immutable copy of {@link Sets#union(Set, Set)} over more contrived alternatives. */
+  static final class SetsUnion<S, T extends S, U extends S> {
+    @BeforeTemplate
+    ImmutableSet<S> before(Set<T> set1, Set<U> set2) {
+      return Stream.concat(set1.stream(), set2.stream()).collect(toImmutableSet());
+    }
+
+    @AfterTemplate
+    ImmutableSet<S> after(Set<T> set1, Set<U> set2) {
+      return Sets.union(set1, set2).immutableCopy();
+    }
+  }
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/IntStreamRules.java

@@ -1,6 +1,7 @@
 package tech.picnic.errorprone.refasterrules;
 
 import com.google.common.collect.Streams;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.refaster.Refaster;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
@@ -40,6 +41,7 @@ final class IntStreamRules {
     }
 
     @AfterTemplate
+    @CanIgnoreReturnValue
     IntStream after(IntStream stream) {
       return stream;
     }
@@ -250,6 +252,7 @@ final class IntStreamRules {
   /** Prefer {@link IntStream#anyMatch(IntPredicate)} over more contrived alternatives. */
   static final class IntStreamAnyMatch {
     @BeforeTemplate
+    @SuppressWarnings("java:S4034" /* This violation will be rewritten. */)
     boolean before(IntStream stream, IntPredicate predicate) {
       return Refaster.anyOf(
           !stream.noneMatch(predicate), stream.filter(predicate).findAny().isPresent());
@@ -287,4 +290,16 @@ final class IntStreamRules {
       return stream.allMatch(e -> test(e));
     }
   }
+
+  static final class IntStreamTakeWhile {
+    @BeforeTemplate
+    IntStream before(IntStream stream, IntPredicate predicate) {
+      return stream.takeWhile(predicate).filter(predicate);
+    }
+
+    @AfterTemplate
+    IntStream after(IntStream stream, IntPredicate predicate) {
+      return stream.takeWhile(predicate);
+    }
+  }
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/JUnitToAssertJRules.java

@@ -34,8 +34,7 @@ import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
  * <p>Note that, while both libraries throw an {@link AssertionError} in case of an assertion
  * failure, the exact subtype used generally differs.
  */
-// XXX: Not all `org.assertj.core.api.Assertions` methods have an associated Refaster rule yet;
-// expand this class.
+// XXX: Not all JUnit `Assertions` methods have an associated Refaster rule yet; expand this class.
 // XXX: Introduce a `@Matcher` on `Executable` and `ThrowingSupplier` expressions, such that they
 // are only matched if they are also compatible with the `ThrowingCallable` functional interface.
 // When implementing such a matcher, note that expressions with a non-void return type such as
@@ -45,7 +44,7 @@ import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 final class JUnitToAssertJRules {
   private JUnitToAssertJRules() {}
 
-  public ImmutableSet<?> elidedTypesAndStaticImports() {
+  public ImmutableSet<Object> elidedTypesAndStaticImports() {
     return ImmutableSet.of(
         Assertions.class,
         assertDoesNotThrow(() -> null),

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/LongStreamRules.java

@@ -1,6 +1,7 @@
 package tech.picnic.errorprone.refasterrules;
 
 import com.google.common.collect.Streams;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.refaster.Refaster;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
@@ -40,6 +41,7 @@ final class LongStreamRules {
     }
 
     @AfterTemplate
+    @CanIgnoreReturnValue
     LongStream after(LongStream stream) {
       return stream;
     }
@@ -250,6 +252,7 @@ final class LongStreamRules {
   /** Prefer {@link LongStream#anyMatch(LongPredicate)} over more contrived alternatives. */
   static final class LongStreamAnyMatch {
     @BeforeTemplate
+    @SuppressWarnings("java:S4034" /* This violation will be rewritten. */)
     boolean before(LongStream stream, LongPredicate predicate) {
       return Refaster.anyOf(
           !stream.noneMatch(predicate), stream.filter(predicate).findAny().isPresent());
@@ -287,4 +290,16 @@ final class LongStreamRules {
       return stream.allMatch(e -> test(e));
     }
   }
+
+  static final class LongStreamTakeWhile {
+    @BeforeTemplate
+    LongStream before(LongStream stream, LongPredicate predicate) {
+      return stream.takeWhile(predicate).filter(predicate);
+    }
+
+    @AfterTemplate
+    LongStream after(LongStream stream, LongPredicate predicate) {
+      return stream.takeWhile(predicate);
+    }
+  }
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/NullRules.java

@@ -21,11 +21,14 @@ import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 final class NullRules {
   private NullRules() {}
 
-  /** Prefer the {@code ==} operator over {@link Objects#isNull(Object)}. */
+  /**
+   * Prefer the {@code ==} operator (with {@code null} as the second operand) over {@link
+   * Objects#isNull(Object)}.
+   */
   static final class IsNull {
     @BeforeTemplate
     boolean before(@Nullable Object object) {
-      return Objects.isNull(object);
+      return Refaster.anyOf(null == object, Objects.isNull(object));
     }
 
     @AfterTemplate
@@ -34,11 +37,14 @@ final class NullRules {
     }
   }
 
-  /** Prefer the {@code !=} operator over {@link Objects#nonNull(Object)}. */
+  /**
+   * Prefer the {@code !=} operator (with {@code null} as the second operand) over {@link
+   * Objects#nonNull(Object)}.
+   */
   static final class IsNotNull {
     @BeforeTemplate
     boolean before(@Nullable Object object) {
-      return Objects.nonNull(object);
+      return Refaster.anyOf(null != object, Objects.nonNull(object));
     }
 
     @AfterTemplate

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/OptionalRules.java

@@ -3,10 +3,12 @@ package tech.picnic.errorprone.refasterrules;
 import static com.google.errorprone.refaster.ImportPolicy.STATIC_IMPORT_ALWAYS;
 
 import com.google.common.collect.Streams;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.refaster.Refaster;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
 import com.google.errorprone.refaster.annotation.MayOptionallyUse;
+import com.google.errorprone.refaster.annotation.NotMatches;
 import com.google.errorprone.refaster.annotation.Placeholder;
 import com.google.errorprone.refaster.annotation.UseImportPolicy;
 import java.util.Comparator;
@@ -18,6 +20,7 @@ import java.util.function.Supplier;
 import java.util.stream.Stream;
 import org.jspecify.annotations.Nullable;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
+import tech.picnic.errorprone.refaster.matchers.IsLikelyTrivialComputation;
 
 /** Refaster rules related to expressions dealing with {@link Optional}s. */
 @OnlineDocumentation
@@ -68,7 +71,10 @@ final class OptionalRules {
   /** Prefer {@link Optional#orElseThrow()} over the less explicit {@link Optional#get()}. */
   static final class OptionalOrElseThrow<T> {
     @BeforeTemplate
-    @SuppressWarnings("NullAway")
+    @SuppressWarnings({
+      "java:S3655" /* Matched expressions are in practice embedded in a larger context. */,
+      "NullAway"
+    })
     T before(Optional<T> optional) {
       return optional.get();
     }
@@ -94,6 +100,20 @@ final class OptionalRules {
     }
   }
 
+  /** Prefer {@link Optional#equals(Object)} over more contrived alternatives. */
+  static final class OptionalEqualsOptional<T, S> {
+    @BeforeTemplate
+    boolean before(Optional<T> optional, S value) {
+      return Refaster.anyOf(
+          optional.filter(value::equals).isPresent(), optional.stream().anyMatch(value::equals));
+    }
+
+    @AfterTemplate
+    boolean after(Optional<T> optional, S value) {
+      return optional.equals(Optional.of(value));
+    }
+  }
+
   /**
    * Don't use the ternary operator to extract the first element of a possibly-empty {@link
    * Iterator} as an {@link Optional}.
@@ -114,7 +134,7 @@ final class OptionalRules {
   /** Prefer {@link Optional#filter(Predicate)} over usage of the ternary operator. */
   // XXX: This rule may introduce a compilation error: the `test` expression may reference a
   // non-effectively final variable, which is not allowed in the replacement lambda expression.
-  // Maybe our `Refaster` checker should test `compilesWithFix`?
+  // Review whether a `@Matcher` can be used to avoid this.
   abstract static class TernaryOperatorOptionalPositiveFiltering<T> {
     @Placeholder
     abstract boolean test(T value);
@@ -134,7 +154,7 @@ final class OptionalRules {
   /** Prefer {@link Optional#filter(Predicate)} over usage of the ternary operator. */
   // XXX: This rule may introduce a compilation error: the `test` expression may reference a
   // non-effectively final variable, which is not allowed in the replacement lambda expression.
-  // Maybe our `Refaster` checker should test `compilesWithFix`?
+  // Review whether a `@Matcher` can be used to avoid this.
   abstract static class TernaryOperatorOptionalNegativeFiltering<T> {
     @Placeholder
     abstract boolean test(T value);
@@ -157,6 +177,7 @@ final class OptionalRules {
    */
   static final class MapOptionalToBoolean<T> {
     @BeforeTemplate
+    @SuppressWarnings("OptionalOrElseGet" /* Rule is confused by `Refaster#anyOf` usage. */)
     boolean before(Optional<T> optional, Function<? super T, Boolean> predicate) {
       return optional.map(predicate).orElse(Refaster.anyOf(false, Boolean.FALSE));
     }
@@ -220,6 +241,28 @@ final class OptionalRules {
     }
   }
 
+  /**
+   * Prefer {@link Optional#orElseGet(Supplier)} over {@link Optional#orElse(Object)} if the
+   * fallback value is not the result of a trivial computation.
+   */
+  // XXX: This rule may introduce a compilation error: the `value` expression may reference a
+  // non-effectively final variable, which is not allowed in the replacement lambda expression.
+  // Review whether a `@Matcher` can be used to avoid this.
+  // XXX: Once `MethodReferenceUsage` is "production ready", replace
+  // `@NotMatches(IsLikelyTrivialComputation.class)` with `@Matches(RequiresComputation.class)` (and
+  // reimplement the matcher accordingly).
+  static final class OptionalOrElseGet<T> {
+    @BeforeTemplate
+    T before(Optional<T> optional, @NotMatches(IsLikelyTrivialComputation.class) T value) {
+      return optional.orElse(value);
+    }
+
+    @AfterTemplate
+    T after(Optional<T> optional, T value) {
+      return optional.orElseGet(() -> value);
+    }
+  }
+
   /**
    * Flatten a stream of {@link Optional}s using {@link Optional#stream()}, rather than using one of
    * the more verbose alternatives.
@@ -304,14 +347,12 @@ final class OptionalRules {
     abstract Optional<S> toOptionalFunction(@MayOptionallyUse T element);
 
     @BeforeTemplate
-    Optional<R> before(
-        Optional<T> optional, Function<? super S, ? extends Optional<? extends R>> function) {
+    Optional<R> before(Optional<T> optional, Function<? super S, Optional<? extends R>> function) {
       return optional.flatMap(v -> toOptionalFunction(v).flatMap(function));
     }
 
     @AfterTemplate
-    Optional<R> after(
-        Optional<T> optional, Function<? super S, ? extends Optional<? extends R>> function) {
+    Optional<R> after(Optional<T> optional, Function<? super S, Optional<? extends R>> function) {
       return optional.flatMap(v -> toOptionalFunction(v)).flatMap(function);
     }
   }
@@ -323,10 +364,14 @@ final class OptionalRules {
     Optional<T> before(Optional<T> optional1, Optional<T> optional2) {
       // XXX: Note that rewriting the first and third variant will change the code's behavior if
       // `optional2` has side-effects.
+      // XXX: Note that rewriting the first, third and fourth variant will introduce a compilation
+      // error if `optional2` is not effectively final. Review whether a `@Matcher` can be used to
+      // avoid this.
       return Refaster.anyOf(
           optional1.map(Optional::of).orElse(optional2),
           optional1.map(Optional::of).orElseGet(() -> optional2),
-          Stream.of(optional1, optional2).flatMap(Optional::stream).findFirst());
+          Stream.of(optional1, optional2).flatMap(Optional::stream).findFirst(),
+          optional1.isPresent() ? optional1 : optional2);
     }
 
     @AfterTemplate
@@ -350,6 +395,7 @@ final class OptionalRules {
     }
 
     @AfterTemplate
+    @CanIgnoreReturnValue
     Optional<T> after(Optional<T> optional) {
       return optional;
     }
@@ -391,12 +437,22 @@ final class OptionalRules {
     }
   }
 
-  // XXX: Add a rule for:
-  // `optional.flatMap(x -> pred(x) ? Optional.empty() : Optional.of(x))` and variants.
-  // (Maybe canonicalize the inner expression. Maybe we rewrite already.)
+  /** Prefer {@link Optional#stream()} over more contrived alternatives. */
+  static final class OptionalStream<T> {
+    @BeforeTemplate
+    Stream<T> before(Optional<T> optional) {
+      return Refaster.anyOf(
+          optional.map(Stream::of).orElse(Stream.empty()),
+          optional.map(Stream::of).orElseGet(Stream::empty));
+    }
+
+    @AfterTemplate
+    Stream<T> after(Optional<T> optional) {
+      return optional.stream();
+    }
+  }
 
   // XXX: Add a rule for:
-  // `optional.map(Stream::of).orElse(Stream.empty())`
-  // `optional.map(Stream::of).orElseGet(Stream::empty)`
-  // -> `optional.stream()`
+  // `optional.flatMap(x -> pred(x) ? Optional.empty() : Optional.of(x))` and variants.
+  // (Maybe canonicalize the inner expression. Maybe we rewrite it already.)
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/PreconditionsRules.java

@@ -6,11 +6,13 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkPositionIndex;
 import static com.google.common.base.Preconditions.checkState;
 import static com.google.errorprone.refaster.ImportPolicy.STATIC_IMPORT_ALWAYS;
+import static java.util.Objects.requireNonNull;
 
 import com.google.common.base.Preconditions;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
 import com.google.errorprone.refaster.annotation.UseImportPolicy;
+import java.util.Objects;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 
 /** Refaster templates related to statements dealing with {@link Preconditions}. */
@@ -72,9 +74,24 @@ final class PreconditionsRules {
     }
   }
 
-  /** Prefer {@link Preconditions#checkNotNull(Object)} over more verbose alternatives. */
-  static final class CheckNotNull<T> {
+  /** Prefer {@link Objects#requireNonNull(Object)} over non-JDK alternatives. */
+  static final class RequireNonNull<T> {
     @BeforeTemplate
+    T before(T object) {
+      return checkNotNull(object);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    T after(T object) {
+      return requireNonNull(object);
+    }
+  }
+
+  /** Prefer {@link Objects#requireNonNull(Object)} over more verbose alternatives. */
+  static final class RequireNonNullStatement<T> {
+    @BeforeTemplate
+    @SuppressWarnings("java:S1695" /* This violation will be rewritten. */)
     void before(T object) {
       if (object == null) {
         throw new NullPointerException();
@@ -84,13 +101,28 @@ final class PreconditionsRules {
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     void after(T object) {
-      checkNotNull(object);
+      requireNonNull(object);
     }
   }
 
-  /** Prefer {@link Preconditions#checkNotNull(Object, Object)} over more verbose alternatives. */
-  static final class CheckNotNullWithMessage<T> {
+  /** Prefer {@link Objects#requireNonNull(Object, String)} over non-JDK alternatives. */
+  static final class RequireNonNullWithMessage<T> {
     @BeforeTemplate
+    T before(T object, String message) {
+      return checkNotNull(object, message);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    T after(T object, String message) {
+      return requireNonNull(object, message);
+    }
+  }
+
+  /** Prefer {@link Objects#requireNonNull(Object, String)} over more verbose alternatives. */
+  static final class RequireNonNullWithMessageStatement<T> {
+    @BeforeTemplate
+    @SuppressWarnings("java:S1695" /* This violation will be rewritten. */)
     void before(T object, String message) {
       if (object == null) {
         throw new NullPointerException(message);
@@ -100,7 +132,7 @@ final class PreconditionsRules {
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     void after(T object, String message) {
-      checkNotNull(object, message);
+      requireNonNull(object, message);
     }
   }
 

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/PrimitiveRules.java

@@ -1,6 +1,13 @@
 package tech.picnic.errorprone.refasterrules;
 
+import com.google.common.primitives.Booleans;
+import com.google.common.primitives.Bytes;
+import com.google.common.primitives.Chars;
+import com.google.common.primitives.Doubles;
+import com.google.common.primitives.Floats;
 import com.google.common.primitives.Ints;
+import com.google.common.primitives.Longs;
+import com.google.common.primitives.Shorts;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
@@ -13,12 +20,13 @@ final class PrimitiveRules {
   /** Avoid contrived ways of expressing the "less than" relationship. */
   static final class LessThan {
     @BeforeTemplate
+    @SuppressWarnings("java:S1940" /* This violation will be rewritten. */)
     boolean before(double a, double b) {
       return !(a >= b);
     }
 
     @AfterTemplate
-    boolean after(long a, long b) {
+    boolean after(double a, double b) {
       return a < b;
     }
   }
@@ -26,12 +34,13 @@ final class PrimitiveRules {
   /** Avoid contrived ways of expressing the "less than or equal to" relationship. */
   static final class LessThanOrEqualTo {
     @BeforeTemplate
+    @SuppressWarnings("java:S1940" /* This violation will be rewritten. */)
     boolean before(double a, double b) {
       return !(a > b);
     }
 
     @AfterTemplate
-    boolean after(long a, long b) {
+    boolean after(double a, double b) {
       return a <= b;
     }
   }
@@ -39,12 +48,13 @@ final class PrimitiveRules {
   /** Avoid contrived ways of expressing the "greater than" relationship. */
   static final class GreaterThan {
     @BeforeTemplate
+    @SuppressWarnings("java:S1940" /* This violation will be rewritten. */)
     boolean before(double a, double b) {
       return !(a <= b);
     }
 
     @AfterTemplate
-    boolean after(long a, long b) {
+    boolean after(double a, double b) {
       return a > b;
     }
   }
@@ -52,12 +62,13 @@ final class PrimitiveRules {
   /** Avoid contrived ways of expressing the "greater than or equal to" relationship. */
   static final class GreaterThanOrEqualTo {
     @BeforeTemplate
+    @SuppressWarnings("java:S1940" /* This violation will be rewritten. */)
     boolean before(double a, double b) {
       return !(a < b);
     }
 
     @AfterTemplate
-    boolean after(long a, long b) {
+    boolean after(double a, double b) {
       return a >= b;
     }
   }
@@ -65,13 +76,312 @@ final class PrimitiveRules {
   /** Prefer {@link Math#toIntExact(long)} over the Guava alternative. */
   static final class LongToIntExact {
     @BeforeTemplate
-    int before(long a) {
-      return Ints.checkedCast(a);
+    int before(long l) {
+      return Ints.checkedCast(l);
     }
 
     @AfterTemplate
-    int after(long a) {
-      return Math.toIntExact(a);
+    int after(long l) {
+      return Math.toIntExact(l);
+    }
+  }
+
+  /** Prefer {@link Boolean#hashCode(boolean)} over the Guava alternative. */
+  static final class BooleanHashCode {
+    @BeforeTemplate
+    int before(boolean b) {
+      return Booleans.hashCode(b);
+    }
+
+    @AfterTemplate
+    int after(boolean b) {
+      return Boolean.hashCode(b);
+    }
+  }
+
+  /** Prefer {@link Byte#hashCode(byte)} over the Guava alternative. */
+  static final class ByteHashCode {
+    @BeforeTemplate
+    int before(byte b) {
+      return Bytes.hashCode(b);
+    }
+
+    @AfterTemplate
+    int after(byte b) {
+      return Byte.hashCode(b);
+    }
+  }
+
+  /** Prefer {@link Character#hashCode(char)} over the Guava alternative. */
+  static final class CharacterHashCode {
+    @BeforeTemplate
+    int before(char c) {
+      return Chars.hashCode(c);
+    }
+
+    @AfterTemplate
+    int after(char c) {
+      return Character.hashCode(c);
+    }
+  }
+
+  /** Prefer {@link Short#hashCode(short)} over the Guava alternative. */
+  static final class ShortHashCode {
+    @BeforeTemplate
+    int before(short s) {
+      return Shorts.hashCode(s);
+    }
+
+    @AfterTemplate
+    int after(short s) {
+      return Short.hashCode(s);
+    }
+  }
+
+  /** Prefer {@link Integer#hashCode(int)} over the Guava alternative. */
+  static final class IntegerHashCode {
+    @BeforeTemplate
+    int before(int i) {
+      return Ints.hashCode(i);
+    }
+
+    @AfterTemplate
+    int after(int i) {
+      return Integer.hashCode(i);
+    }
+  }
+
+  /** Prefer {@link Long#hashCode(long)} over the Guava alternative. */
+  static final class LongHashCode {
+    @BeforeTemplate
+    int before(long l) {
+      return Longs.hashCode(l);
+    }
+
+    @AfterTemplate
+    int after(long l) {
+      return Long.hashCode(l);
+    }
+  }
+
+  /** Prefer {@link Float#hashCode(float)} over the Guava alternative. */
+  static final class FloatHashCode {
+    @BeforeTemplate
+    int before(float f) {
+      return Floats.hashCode(f);
+    }
+
+    @AfterTemplate
+    int after(float f) {
+      return Float.hashCode(f);
+    }
+  }
+
+  /** Prefer {@link Double#hashCode(double)} over the Guava alternative. */
+  static final class DoubleHashCode {
+    @BeforeTemplate
+    int before(double d) {
+      return Doubles.hashCode(d);
+    }
+
+    @AfterTemplate
+    int after(double d) {
+      return Double.hashCode(d);
+    }
+  }
+
+  /** Prefer {@link Boolean#compare(boolean, boolean)} over the Guava alternative. */
+  static final class BooleanCompare {
+    @BeforeTemplate
+    int before(boolean a, boolean b) {
+      return Booleans.compare(a, b);
+    }
+
+    @AfterTemplate
+    int after(boolean a, boolean b) {
+      return Boolean.compare(a, b);
+    }
+  }
+
+  /** Prefer {@link Character#compare(char, char)} over the Guava alternative. */
+  static final class CharacterCompare {
+    @BeforeTemplate
+    int before(char a, char b) {
+      return Chars.compare(a, b);
+    }
+
+    @AfterTemplate
+    int after(char a, char b) {
+      return Character.compare(a, b);
+    }
+  }
+
+  /** Prefer {@link Short#compare(short, short)} over the Guava alternative. */
+  static final class ShortCompare {
+    @BeforeTemplate
+    int before(short a, short b) {
+      return Shorts.compare(a, b);
+    }
+
+    @AfterTemplate
+    int after(short a, short b) {
+      return Short.compare(a, b);
+    }
+  }
+
+  /** Prefer {@link Integer#compare(int, int)} over the Guava alternative. */
+  static final class IntegerCompare {
+    @BeforeTemplate
+    int before(int a, int b) {
+      return Ints.compare(a, b);
+    }
+
+    @AfterTemplate
+    int after(int a, int b) {
+      return Integer.compare(a, b);
+    }
+  }
+
+  /** Prefer {@link Long#compare(long, long)} over the Guava alternative. */
+  static final class LongCompare {
+    @BeforeTemplate
+    int before(long a, long b) {
+      return Longs.compare(a, b);
+    }
+
+    @AfterTemplate
+    int after(long a, long b) {
+      return Long.compare(a, b);
+    }
+  }
+
+  /** Prefer {@link Float#compare(float, float)} over the Guava alternative. */
+  static final class FloatCompare {
+    @BeforeTemplate
+    int before(float a, float b) {
+      return Floats.compare(a, b);
+    }
+
+    @AfterTemplate
+    int after(float a, float b) {
+      return Float.compare(a, b);
+    }
+  }
+
+  /** Prefer {@link Double#compare(double, double)} over the Guava alternative. */
+  static final class DoubleCompare {
+    @BeforeTemplate
+    int before(double a, double b) {
+      return Doubles.compare(a, b);
+    }
+
+    @AfterTemplate
+    int after(double a, double b) {
+      return Double.compare(a, b);
+    }
+  }
+
+  /** Prefer {@link Character#BYTES} over the Guava alternative. */
+  static final class CharacterBytes {
+    @BeforeTemplate
+    int before() {
+      return Chars.BYTES;
+    }
+
+    @AfterTemplate
+    int after() {
+      return Character.BYTES;
+    }
+  }
+
+  /** Prefer {@link Short#BYTES} over the Guava alternative. */
+  static final class ShortBytes {
+    @BeforeTemplate
+    int before() {
+      return Shorts.BYTES;
+    }
+
+    @AfterTemplate
+    int after() {
+      return Short.BYTES;
+    }
+  }
+
+  /** Prefer {@link Integer#BYTES} over the Guava alternative. */
+  static final class IntegerBytes {
+    @BeforeTemplate
+    int before() {
+      return Ints.BYTES;
+    }
+
+    @AfterTemplate
+    int after() {
+      return Integer.BYTES;
+    }
+  }
+
+  /** Prefer {@link Long#BYTES} over the Guava alternative. */
+  static final class LongBytes {
+    @BeforeTemplate
+    int before() {
+      return Longs.BYTES;
+    }
+
+    @AfterTemplate
+    int after() {
+      return Long.BYTES;
+    }
+  }
+
+  /** Prefer {@link Float#BYTES} over the Guava alternative. */
+  static final class FloatBytes {
+    @BeforeTemplate
+    int before() {
+      return Floats.BYTES;
+    }
+
+    @AfterTemplate
+    int after() {
+      return Float.BYTES;
+    }
+  }
+
+  /** Prefer {@link Double#BYTES} over the Guava alternative. */
+  static final class DoubleBytes {
+    @BeforeTemplate
+    int before() {
+      return Doubles.BYTES;
+    }
+
+    @AfterTemplate
+    int after() {
+      return Double.BYTES;
+    }
+  }
+
+  /** Prefer {@link Float#isFinite(float)} over the Guava alternative. */
+  static final class FloatIsFinite {
+    @BeforeTemplate
+    boolean before(float f) {
+      return Floats.isFinite(f);
+    }
+
+    @AfterTemplate
+    boolean after(float f) {
+      return Float.isFinite(f);
+    }
+  }
+
+  /** Prefer {@link Double#isFinite(double)} over the Guava alternative. */
+  static final class DoubleIsFinite {
+    @BeforeTemplate
+    boolean before(double d) {
+      return Doubles.isFinite(d);
+    }
+
+    @AfterTemplate
+    boolean after(double d) {
+      return Double.isFinite(d);
     }
   }
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java

@@ -1,14 +1,20 @@
 package tech.picnic.errorprone.refasterrules;
 
+import static com.google.common.collect.ImmutableList.toImmutableList;
+import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static com.google.common.collect.MoreCollectors.toOptional;
 import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
 import static com.google.errorprone.refaster.ImportPolicy.STATIC_IMPORT_ALWAYS;
 import static java.util.function.Function.identity;
+import static java.util.stream.Collectors.toCollection;
 import static org.assertj.core.api.Assertions.assertThat;
 import static reactor.function.TupleUtils.function;
 
+import com.google.common.collect.ImmutableCollection;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.MoreCollectors;
+import com.google.common.collect.ImmutableSet;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.refaster.Refaster;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
@@ -17,8 +23,11 @@ import com.google.errorprone.refaster.annotation.NotMatches;
 import com.google.errorprone.refaster.annotation.Placeholder;
 import com.google.errorprone.refaster.annotation.UseImportPolicy;
 import java.time.Duration;
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Comparator;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.Callable;
 import java.util.function.BiConsumer;
@@ -27,6 +36,7 @@ import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
+import java.util.stream.Collector;
 import org.jspecify.annotations.Nullable;
 import org.reactivestreams.Publisher;
 import reactor.core.publisher.Flux;
@@ -88,7 +98,7 @@ final class ReactorRules {
   }
 
   /** Prefer {@link Mono#justOrEmpty(Object)} over more contrived alternatives. */
-  static final class MonoJustOrEmpty<@Nullable T> {
+  static final class MonoJustOrEmptyObject<@Nullable T> {
     @BeforeTemplate
     Mono<T> before(T value) {
       return Mono.justOrEmpty(Optional.ofNullable(value));
@@ -101,9 +111,25 @@ final class ReactorRules {
   }
 
   /** Prefer {@link Mono#justOrEmpty(Optional)} over more verbose alternatives. */
+  static final class MonoJustOrEmptyOptional<T> {
+    @BeforeTemplate
+    Mono<T> before(Optional<T> optional) {
+      return Mono.just(optional).filter(Optional::isPresent).map(Optional::orElseThrow);
+    }
+
+    @AfterTemplate
+    Mono<T> after(Optional<T> optional) {
+      return Mono.justOrEmpty(optional);
+    }
+  }
+
+  /**
+   * Prefer {@link Mono#defer(Supplier) deferring} {@link Mono#justOrEmpty(Optional)} over more
+   * verbose alternatives.
+   */
   // XXX: If `optional` is a constant and effectively-final expression then the `Mono.defer` can be
   // dropped. Should look into Refaster support for identifying this.
-  static final class MonoFromOptional<T> {
+  static final class MonoDeferMonoJustOrEmpty<T> {
     @BeforeTemplate
     @SuppressWarnings(
         "MonoFromSupplier" /* `optional` may match a checked exception-throwing expression. */)
@@ -378,12 +404,33 @@ final class ReactorRules {
       return mono.then();
     }
 
+    // XXX: Replace this rule with an extension of the `IdentityConversion` rule, supporting
+    // `Stream#map`, `Mono#map` and `Flux#map`.
+    @BeforeTemplate
+    Mono<ImmutableList<T>> before3(Mono<ImmutableList<T>> mono) {
+      return mono.map(ImmutableList::copyOf);
+    }
+
     @AfterTemplate
+    @CanIgnoreReturnValue
     Mono<T> after(Mono<T> mono) {
       return mono;
     }
   }
 
+  /** Don't unnecessarily transform a {@link Mono} to a {@link Flux} to expect exactly one item. */
+  static final class MonoSingle<T> {
+    @BeforeTemplate
+    Mono<T> before(Mono<T> mono) {
+      return mono.flux().single();
+    }
+
+    @AfterTemplate
+    Mono<T> after(Mono<T> mono) {
+      return mono.single();
+    }
+  }
+
   /** Don't unnecessarily pass an empty publisher to {@link Flux#switchIfEmpty(Publisher)}. */
   static final class FluxSwitchIfEmptyOfEmptyPublisher<T> {
     @BeforeTemplate
@@ -392,6 +439,7 @@ final class ReactorRules {
     }
 
     @AfterTemplate
+    @CanIgnoreReturnValue
     Flux<T> after(Flux<T> flux) {
       return flux;
     }
@@ -400,6 +448,7 @@ final class ReactorRules {
   /** Prefer {@link Flux#concatMap(Function)} over more contrived alternatives. */
   static final class FluxConcatMap<T, S> {
     @BeforeTemplate
+    @SuppressWarnings("NestedPublishers")
     Flux<S> before(Flux<T> flux, Function<? super T, ? extends Publisher<? extends S>> function) {
       return Refaster.anyOf(
           flux.flatMap(function, 1),
@@ -416,6 +465,7 @@ final class ReactorRules {
   /** Prefer {@link Flux#concatMap(Function, int)} over more contrived alternatives. */
   static final class FluxConcatMapWithPrefetch<T, S> {
     @BeforeTemplate
+    @SuppressWarnings("NestedPublishers")
     Flux<S> before(
         Flux<T> flux,
         Function<? super T, ? extends Publisher<? extends S>> function,
@@ -588,6 +638,7 @@ final class ReactorRules {
     abstract S transformation(@MayOptionallyUse T value);
 
     @BeforeTemplate
+    @SuppressWarnings("java:S138" /* Method is long, but not complex. */)
     Publisher<S> before(Flux<T> flux, boolean delayUntilEnd, int maxConcurrency, int prefetch) {
       return Refaster.anyOf(
           flux.concatMap(
@@ -699,21 +750,21 @@ final class ReactorRules {
     }
   }
 
-  /**
-   * Prefer a collection using {@link MoreCollectors#toOptional()} over more contrived alternatives.
-   */
+  /** Prefer {@link Mono#singleOptional()} over more contrived alternatives. */
   // XXX: Consider creating a plugin that flags/discourages `Mono<Optional<T>>` method return
   // types, just as we discourage nullable `Boolean`s and `Optional`s.
-  static final class MonoCollectToOptional<T> {
+  static final class MonoSingleOptional<T> {
     @BeforeTemplate
     Mono<Optional<T>> before(Mono<T> mono) {
-      return mono.map(Optional::of).defaultIfEmpty(Optional.empty());
+      return Refaster.anyOf(
+          mono.flux().collect(toOptional()),
+          mono.map(Optional::of).defaultIfEmpty(Optional.empty()));
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     Mono<Optional<T>> after(Mono<T> mono) {
-      return mono.flux().collect(toOptional());
+      return mono.singleOptional();
     }
   }
 
@@ -746,6 +797,7 @@ final class ReactorRules {
   /** Prefer {@link Mono#flatMap(Function)} over more contrived alternatives. */
   static final class MonoFlatMap<S, T> {
     @BeforeTemplate
+    @SuppressWarnings("NestedPublishers")
     Mono<T> before(Mono<S> mono, Function<? super S, ? extends Mono<? extends T>> function) {
       return mono.map(function).flatMap(identity());
     }
@@ -759,6 +811,7 @@ final class ReactorRules {
   /** Prefer {@link Mono#flatMapMany(Function)} over more contrived alternatives. */
   static final class MonoFlatMapMany<S, T> {
     @BeforeTemplate
+    @SuppressWarnings("NestedPublishers")
     Flux<T> before(Mono<S> mono, Function<? super S, ? extends Publisher<? extends T>> function) {
       return mono.map(function).flatMapMany(identity());
     }
@@ -806,6 +859,31 @@ final class ReactorRules {
     }
   }
 
+  /**
+   * Prefer {@link Flux#count()} followed by a conversion from {@code long} to {@code int} over
+   * collecting into a list and counting its elements.
+   */
+  static final class FluxCountMapMathToIntExact<T> {
+    @BeforeTemplate
+    Mono<Integer> before(Flux<T> flux) {
+      return Refaster.anyOf(
+          flux.collect(toImmutableList())
+              .map(
+                  Refaster.anyOf(
+                      Collection::size,
+                      List::size,
+                      ImmutableCollection::size,
+                      ImmutableList::size)),
+          flux.collect(toCollection(ArrayList::new))
+              .map(Refaster.anyOf(Collection::size, List::size)));
+    }
+
+    @AfterTemplate
+    Mono<Integer> after(Flux<T> flux) {
+      return flux.count().map(Math::toIntExact);
+    }
+  }
+
   /**
    * Prefer {@link Mono#doOnError(Class, Consumer)} over {@link Mono#doOnError(Predicate, Consumer)}
    * where possible.
@@ -1119,6 +1197,56 @@ final class ReactorRules {
     }
   }
 
+  /**
+   * Do not unnecessarily {@link Flux#filter(Predicate) filter} the result of {@link
+   * Flux#takeWhile(Predicate)} using the same {@link Predicate}.
+   */
+  static final class FluxTakeWhile<T> {
+    @BeforeTemplate
+    Flux<T> before(Flux<T> flux, Predicate<? super T> predicate) {
+      return flux.takeWhile(predicate).filter(predicate);
+    }
+
+    @AfterTemplate
+    Flux<T> after(Flux<T> flux, Predicate<? super T> predicate) {
+      return flux.takeWhile(predicate);
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#collect(Collector)} with {@link ImmutableList#toImmutableList()} over
+   * alternatives that do not explicitly return an immutable collection.
+   */
+  static final class FluxCollectToImmutableList<T> {
+    @BeforeTemplate
+    Mono<List<T>> before(Flux<T> flux) {
+      return flux.collectList();
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    Mono<ImmutableList<T>> after(Flux<T> flux) {
+      return flux.collect(toImmutableList());
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#collect(Collector)} with {@link ImmutableSet#toImmutableSet()} over more
+   * contrived alternatives.
+   */
+  static final class FluxCollectToImmutableSet<T> {
+    @BeforeTemplate
+    Mono<ImmutableSet<T>> before(Flux<T> flux) {
+      return flux.collect(toImmutableList()).map(ImmutableSet::copyOf);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    Mono<ImmutableSet<T>> after(Flux<T> flux) {
+      return flux.collect(toImmutableSet());
+    }
+  }
+
   /** Prefer {@link reactor.util.context.Context#empty()}} over more verbose alternatives. */
   // XXX: Consider introducing an `IsEmpty` matcher that identifies a wide range of guaranteed-empty
   // `Collection` and `Map` expressions.
@@ -1173,15 +1301,18 @@ final class ReactorRules {
     }
   }
 
-  /** Don't unnecessarily call {@link StepVerifier.Step#expectNext(Object[])}. */
-  static final class StepVerifierStepExpectNextEmpty<T> {
+  /** Don't unnecessarily have {@link StepVerifier.Step} expect no elements. */
+  // XXX: Given an `IsEmpty` matcher that identifies a wide range of guaranteed-empty `Iterable`
+  // expressions, consider also simplifying `step.expectNextSequence(someEmptyIterable)`.
+  static final class StepVerifierStepIdentity<T> {
     @BeforeTemplate
     @SuppressWarnings("unchecked")
     StepVerifier.Step<T> before(StepVerifier.Step<T> step) {
-      return step.expectNext();
+      return Refaster.anyOf(step.expectNext(), step.expectNextCount(0));
     }
 
     @AfterTemplate
+    @CanIgnoreReturnValue
     StepVerifier.Step<T> after(StepVerifier.Step<T> step) {
       return step;
     }
@@ -1201,6 +1332,23 @@ final class ReactorRules {
     }
   }
 
+  /** Avoid list collection when verifying that a {@link Flux} emits exactly one value. */
+  // XXX: This rule assumes that the matched collector does not drop elements. Consider introducing
+  // a `@Matches(DoesNotDropElements.class)` or `@NotMatches(MayDropElements.class)` guard.
+  static final class FluxAsStepVerifierExpectNext<T, L extends List<T>> {
+    @BeforeTemplate
+    StepVerifier.Step<L> before(Flux<T> flux, Collector<? super T, ?, L> listCollector, T object) {
+      return flux.collect(listCollector)
+          .as(StepVerifier::create)
+          .assertNext(list -> assertThat(list).containsExactly(object));
+    }
+
+    @AfterTemplate
+    StepVerifier.Step<T> after(Flux<T> flux, T object) {
+      return flux.as(StepVerifier::create).expectNext(object);
+    }
+  }
+
   /** Prefer {@link StepVerifier.LastStep#verifyComplete()} over more verbose alternatives. */
   static final class StepVerifierLastStepVerifyComplete {
     @BeforeTemplate

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/StreamRules.java

@@ -3,26 +3,55 @@ package tech.picnic.errorprone.refasterrules;
 import static com.google.errorprone.refaster.ImportPolicy.STATIC_IMPORT_ALWAYS;
 import static java.util.Comparator.naturalOrder;
 import static java.util.Comparator.reverseOrder;
+import static java.util.function.Function.identity;
 import static java.util.function.Predicate.not;
+import static java.util.stream.Collectors.counting;
+import static java.util.stream.Collectors.filtering;
+import static java.util.stream.Collectors.flatMapping;
 import static java.util.stream.Collectors.joining;
+import static java.util.stream.Collectors.mapping;
+import static java.util.stream.Collectors.maxBy;
+import static java.util.stream.Collectors.minBy;
+import static java.util.stream.Collectors.reducing;
+import static java.util.stream.Collectors.summarizingDouble;
+import static java.util.stream.Collectors.summarizingInt;
+import static java.util.stream.Collectors.summarizingLong;
+import static java.util.stream.Collectors.summingDouble;
+import static java.util.stream.Collectors.summingInt;
+import static java.util.stream.Collectors.summingLong;
 
 import com.google.common.collect.Streams;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.refaster.Refaster;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
+import com.google.errorprone.refaster.annotation.Matches;
 import com.google.errorprone.refaster.annotation.MayOptionallyUse;
+import com.google.errorprone.refaster.annotation.NotMatches;
 import com.google.errorprone.refaster.annotation.Placeholder;
+import com.google.errorprone.refaster.annotation.Repeated;
 import com.google.errorprone.refaster.annotation.UseImportPolicy;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Comparator;
+import java.util.DoubleSummaryStatistics;
+import java.util.IntSummaryStatistics;
+import java.util.LongSummaryStatistics;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.function.BinaryOperator;
 import java.util.function.Function;
 import java.util.function.Predicate;
+import java.util.function.ToDoubleFunction;
+import java.util.function.ToIntFunction;
+import java.util.function.ToLongFunction;
+import java.util.function.UnaryOperator;
 import java.util.stream.Collector;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
+import tech.picnic.errorprone.refaster.matchers.IsLambdaExpressionOrMethodReference;
+import tech.picnic.errorprone.refaster.matchers.IsRefasterAsVarargs;
 
 /** Refaster rules related to expressions dealing with {@link Stream}s. */
 @OnlineDocumentation
@@ -77,12 +106,9 @@ final class StreamRules {
    * Prefer {@link Arrays#stream(Object[])} over {@link Stream#of(Object[])}, as the former is
    * clearer.
    */
-  // XXX: Introduce a `Matcher` that identifies `Refaster.asVarargs(...)` invocations and annotate
-  // the `array` parameter as `@NotMatches(IsRefasterAsVarargs.class)`. Then elsewhere
-  // `@SuppressWarnings("StreamOfArray")` annotations can be dropped.
   static final class StreamOfArray<T> {
     @BeforeTemplate
-    Stream<T> before(T[] array) {
+    Stream<T> before(@NotMatches(IsRefasterAsVarargs.class) T[] array) {
       return Stream.of(array);
     }
 
@@ -100,6 +126,7 @@ final class StreamRules {
     }
 
     @AfterTemplate
+    @CanIgnoreReturnValue
     Stream<T> after(Stream<T> stream) {
       return stream;
     }
@@ -223,14 +250,18 @@ final class StreamRules {
   }
 
   /** In order to test whether a stream has any element, simply try to find one. */
+  // XXX: This rule assumes that any matched `Collector` does not perform any filtering.
+  // (Perhaps we could add a `@Matches` guard that validates that the collector expression does not
+  // contain a `Collectors#filtering` call. That'd still not be 100% accurate, though.)
   static final class StreamIsEmpty<T> {
     @BeforeTemplate
-    boolean before(Stream<T> stream) {
+    boolean before(Stream<T> stream, Collector<? super T, ?, ? extends Collection<?>> collector) {
       return Refaster.anyOf(
           stream.count() == 0,
           stream.count() <= 0,
           stream.count() < 1,
-          stream.findFirst().isEmpty());
+          stream.findFirst().isEmpty(),
+          stream.collect(collector).isEmpty());
     }
 
     @AfterTemplate
@@ -258,9 +289,12 @@ final class StreamRules {
 
   static final class StreamMin<T> {
     @BeforeTemplate
+    @SuppressWarnings("java:S4266" /* This violation will be rewritten. */)
     Optional<T> before(Stream<T> stream, Comparator<? super T> comparator) {
       return Refaster.anyOf(
-          stream.max(comparator.reversed()), stream.sorted(comparator).findFirst());
+          stream.max(comparator.reversed()),
+          stream.sorted(comparator).findFirst(),
+          stream.collect(minBy(comparator)));
     }
 
     @AfterTemplate
@@ -284,9 +318,12 @@ final class StreamRules {
 
   static final class StreamMax<T> {
     @BeforeTemplate
+    @SuppressWarnings("java:S4266" /* This violation will be rewritten. */)
     Optional<T> before(Stream<T> stream, Comparator<? super T> comparator) {
       return Refaster.anyOf(
-          stream.min(comparator.reversed()), Streams.findLast(stream.sorted(comparator)));
+          stream.min(comparator.reversed()),
+          Streams.findLast(stream.sorted(comparator)),
+          stream.collect(maxBy(comparator)));
     }
 
     @AfterTemplate
@@ -311,6 +348,7 @@ final class StreamRules {
   /** Prefer {@link Stream#noneMatch(Predicate)} over more contrived alternatives. */
   static final class StreamNoneMatch<T> {
     @BeforeTemplate
+    @SuppressWarnings("java:S4034" /* This violation will be rewritten. */)
     boolean before(Stream<T> stream, Predicate<? super T> predicate) {
       return Refaster.anyOf(
           !stream.anyMatch(predicate),
@@ -318,6 +356,14 @@ final class StreamRules {
           stream.filter(predicate).findAny().isEmpty());
     }
 
+    @BeforeTemplate
+    boolean before2(
+        Stream<T> stream,
+        @Matches(IsLambdaExpressionOrMethodReference.class)
+            Function<? super T, Boolean> predicate) {
+      return stream.map(predicate).noneMatch(Refaster.anyOf(Boolean::booleanValue, b -> b));
+    }
+
     @AfterTemplate
     boolean after(Stream<T> stream, Predicate<? super T> predicate) {
       return stream.noneMatch(predicate);
@@ -342,11 +388,20 @@ final class StreamRules {
   /** Prefer {@link Stream#anyMatch(Predicate)} over more contrived alternatives. */
   static final class StreamAnyMatch<T> {
     @BeforeTemplate
+    @SuppressWarnings("java:S4034" /* This violation will be rewritten. */)
     boolean before(Stream<T> stream, Predicate<? super T> predicate) {
       return Refaster.anyOf(
           !stream.noneMatch(predicate), stream.filter(predicate).findAny().isPresent());
     }
 
+    @BeforeTemplate
+    boolean before2(
+        Stream<T> stream,
+        @Matches(IsLambdaExpressionOrMethodReference.class)
+            Function<? super T, Boolean> predicate) {
+      return stream.map(predicate).anyMatch(Refaster.anyOf(Boolean::booleanValue, b -> b));
+    }
+
     @AfterTemplate
     boolean after(Stream<T> stream, Predicate<? super T> predicate) {
       return stream.anyMatch(predicate);
@@ -359,6 +414,14 @@ final class StreamRules {
       return stream.noneMatch(Refaster.anyOf(not(predicate), predicate.negate()));
     }
 
+    @BeforeTemplate
+    boolean before2(
+        Stream<T> stream,
+        @Matches(IsLambdaExpressionOrMethodReference.class)
+            Function<? super T, Boolean> predicate) {
+      return stream.map(predicate).allMatch(Refaster.anyOf(Boolean::booleanValue, b -> b));
+    }
+
     @AfterTemplate
     boolean after(Stream<T> stream, Predicate<? super T> predicate) {
       return stream.allMatch(predicate);
@@ -379,4 +442,230 @@ final class StreamRules {
       return stream.allMatch(e -> test(e));
     }
   }
+
+  static final class StreamMapToIntSum<T> {
+    @BeforeTemplate
+    @SuppressWarnings("java:S4266" /* This violation will be rewritten. */)
+    long before(Stream<T> stream, ToIntFunction<T> mapper) {
+      return stream.collect(summingInt(mapper));
+    }
+
+    @BeforeTemplate
+    int before2(
+        Stream<T> stream,
+        @Matches(IsLambdaExpressionOrMethodReference.class) Function<? super T, Integer> mapper) {
+      return stream.map(mapper).reduce(0, Integer::sum);
+    }
+
+    @AfterTemplate
+    int after(Stream<T> stream, ToIntFunction<T> mapper) {
+      return stream.mapToInt(mapper).sum();
+    }
+  }
+
+  static final class StreamMapToDoubleSum<T> {
+    @BeforeTemplate
+    @SuppressWarnings("java:S4266" /* This violation will be rewritten. */)
+    double before(Stream<T> stream, ToDoubleFunction<T> mapper) {
+      return stream.collect(summingDouble(mapper));
+    }
+
+    @BeforeTemplate
+    double before2(
+        Stream<T> stream,
+        @Matches(IsLambdaExpressionOrMethodReference.class) Function<? super T, Double> mapper) {
+      return stream.map(mapper).reduce(0.0, Double::sum);
+    }
+
+    @AfterTemplate
+    double after(Stream<T> stream, ToDoubleFunction<T> mapper) {
+      return stream.mapToDouble(mapper).sum();
+    }
+  }
+
+  static final class StreamMapToLongSum<T> {
+    @BeforeTemplate
+    @SuppressWarnings("java:S4266" /* This violation will be rewritten. */)
+    long before(Stream<T> stream, ToLongFunction<T> mapper) {
+      return stream.collect(summingLong(mapper));
+    }
+
+    @BeforeTemplate
+    long before2(
+        Stream<T> stream,
+        @Matches(IsLambdaExpressionOrMethodReference.class) Function<? super T, Long> mapper) {
+      return stream.map(mapper).reduce(0L, Long::sum);
+    }
+
+    @AfterTemplate
+    long after(Stream<T> stream, ToLongFunction<T> mapper) {
+      return stream.mapToLong(mapper).sum();
+    }
+  }
+
+  static final class StreamMapToIntSummaryStatistics<T> {
+    @BeforeTemplate
+    IntSummaryStatistics before(Stream<T> stream, ToIntFunction<T> mapper) {
+      return stream.collect(summarizingInt(mapper));
+    }
+
+    @AfterTemplate
+    IntSummaryStatistics after(Stream<T> stream, ToIntFunction<T> mapper) {
+      return stream.mapToInt(mapper).summaryStatistics();
+    }
+  }
+
+  static final class StreamMapToDoubleSummaryStatistics<T> {
+    @BeforeTemplate
+    DoubleSummaryStatistics before(Stream<T> stream, ToDoubleFunction<T> mapper) {
+      return stream.collect(summarizingDouble(mapper));
+    }
+
+    @AfterTemplate
+    DoubleSummaryStatistics after(Stream<T> stream, ToDoubleFunction<T> mapper) {
+      return stream.mapToDouble(mapper).summaryStatistics();
+    }
+  }
+
+  static final class StreamMapToLongSummaryStatistics<T> {
+    @BeforeTemplate
+    LongSummaryStatistics before(Stream<T> stream, ToLongFunction<T> mapper) {
+      return stream.collect(summarizingLong(mapper));
+    }
+
+    @AfterTemplate
+    LongSummaryStatistics after(Stream<T> stream, ToLongFunction<T> mapper) {
+      return stream.mapToLong(mapper).summaryStatistics();
+    }
+  }
+
+  static final class StreamCount<T> {
+    @BeforeTemplate
+    @SuppressWarnings("java:S4266" /* This violation will be rewritten. */)
+    long before(Stream<T> stream) {
+      return stream.collect(counting());
+    }
+
+    @AfterTemplate
+    long after(Stream<T> stream) {
+      return stream.count();
+    }
+  }
+
+  static final class StreamReduce<T> {
+    @BeforeTemplate
+    @SuppressWarnings("java:S4266" /* This violation will be rewritten. */)
+    Optional<T> before(Stream<T> stream, BinaryOperator<T> accumulator) {
+      return stream.collect(reducing(accumulator));
+    }
+
+    @AfterTemplate
+    Optional<T> after(Stream<T> stream, BinaryOperator<T> accumulator) {
+      return stream.reduce(accumulator);
+    }
+  }
+
+  static final class StreamReduceWithIdentity<T> {
+    @BeforeTemplate
+    @SuppressWarnings("java:S4266" /* This violation will be rewritten. */)
+    T before(Stream<T> stream, T identity, BinaryOperator<T> accumulator) {
+      return stream.collect(reducing(identity, accumulator));
+    }
+
+    @AfterTemplate
+    T after(Stream<T> stream, T identity, BinaryOperator<T> accumulator) {
+      return stream.reduce(identity, accumulator);
+    }
+  }
+
+  static final class StreamFilterCollect<T, R> {
+    @BeforeTemplate
+    R before(
+        Stream<T> stream, Predicate<? super T> predicate, Collector<? super T, ?, R> collector) {
+      return stream.collect(filtering(predicate, collector));
+    }
+
+    @AfterTemplate
+    R after(
+        Stream<T> stream, Predicate<? super T> predicate, Collector<? super T, ?, R> collector) {
+      return stream.filter(predicate).collect(collector);
+    }
+  }
+
+  static final class StreamMapCollect<T, U, R> {
+    @BeforeTemplate
+    @SuppressWarnings("java:S4266" /* This violation will be rewritten. */)
+    R before(
+        Stream<T> stream,
+        Function<? super T, ? extends U> mapper,
+        Collector<? super U, ?, R> collector) {
+      return stream.collect(mapping(mapper, collector));
+    }
+
+    @AfterTemplate
+    R after(
+        Stream<T> stream,
+        Function<? super T, ? extends U> mapper,
+        Collector<? super U, ?, R> collector) {
+      return stream.map(mapper).collect(collector);
+    }
+  }
+
+  static final class StreamFlatMapCollect<T, U, R> {
+    @BeforeTemplate
+    R before(
+        Stream<T> stream,
+        Function<? super T, ? extends Stream<? extends U>> mapper,
+        Collector<? super U, ?, R> collector) {
+      return stream.collect(flatMapping(mapper, collector));
+    }
+
+    @AfterTemplate
+    R after(
+        Stream<T> stream,
+        Function<? super T, ? extends Stream<? extends U>> mapper,
+        Collector<? super U, ?, R> collector) {
+      return stream.flatMap(mapper).collect(collector);
+    }
+  }
+
+  static final class StreamsConcat<T> {
+    @BeforeTemplate
+    Stream<T> before(@Repeated Stream<T> stream) {
+      return Stream.of(Refaster.asVarargs(stream)).flatMap(Refaster.anyOf(identity(), s -> s));
+    }
+
+    @AfterTemplate
+    Stream<T> after(@Repeated Stream<T> stream) {
+      return Streams.concat(Refaster.asVarargs(stream));
+    }
+  }
+
+  static final class StreamTakeWhile<T> {
+    @BeforeTemplate
+    Stream<T> before(Stream<T> stream, Predicate<? super T> predicate) {
+      return stream.takeWhile(predicate).filter(predicate);
+    }
+
+    @AfterTemplate
+    Stream<T> after(Stream<T> stream, Predicate<? super T> predicate) {
+      return stream.takeWhile(predicate);
+    }
+  }
+
+  /**
+   * Prefer {@link Stream#iterate(Object, Predicate, UnaryOperator)} over more contrived
+   * alternatives.
+   */
+  static final class StreamIterate<T> {
+    @BeforeTemplate
+    Stream<T> before(T seed, Predicate<? super T> hasNext, UnaryOperator<T> next) {
+      return Stream.iterate(seed, next).takeWhile(hasNext);
+    }
+
+    @AfterTemplate
+    Stream<T> after(T seed, Predicate<? super T> hasNext, UnaryOperator<T> next) {
+      return Stream.iterate(seed, hasNext, next);
+    }
+  }
 }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/StringRules.java

@@ -1,6 +1,8 @@
 package tech.picnic.errorprone.refasterrules;
 
+import static com.google.errorprone.refaster.ImportPolicy.STATIC_IMPORT_ALWAYS;
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.util.function.Predicate.not;
 import static java.util.stream.Collectors.joining;
 
 import com.google.common.base.Joiner;
@@ -11,21 +13,23 @@ import com.google.errorprone.refaster.Refaster;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.AlsoNegation;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
+import com.google.errorprone.refaster.annotation.UseImportPolicy;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.function.Function;
+import java.util.function.Predicate;
 import org.jspecify.annotations.Nullable;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 
 /** Refaster rules related to expressions dealing with {@link String}s. */
-// XXX: Should we prefer `s -> !s.isEmpty()` or `not(String::isEmpty)`?
 @OnlineDocumentation
 final class StringRules {
   private StringRules() {}
 
   /** Prefer {@link String#isEmpty()} over alternatives that consult the string's length. */
+  // XXX: Once we target JDK 15+, generalize this rule to cover all `CharSequence` subtypes.
   static final class StringIsEmpty {
     @BeforeTemplate
     boolean before(String str) {
@@ -39,6 +43,37 @@ final class StringRules {
     }
   }
 
+  /** Prefer a method reference to {@link String#isEmpty()} over the equivalent lambda function. */
+  // XXX: Once we target JDK 15+, generalize this rule to cover all `CharSequence` subtypes.
+  // XXX: As it stands, this rule is a special case of what `MethodReferenceUsage` tries to achieve.
+  // If/when `MethodReferenceUsage` becomes production ready, we should simply drop this check.
+  static final class StringIsEmptyPredicate {
+    @BeforeTemplate
+    Predicate<String> before() {
+      return s -> s.isEmpty();
+    }
+
+    @AfterTemplate
+    Predicate<String> after() {
+      return String::isEmpty;
+    }
+  }
+
+  /** Prefer a method reference to {@link String#isEmpty()} over the equivalent lambda function. */
+  // XXX: Once we target JDK 15+, generalize this rule to cover all `CharSequence` subtypes.
+  static final class StringIsNotEmptyPredicate {
+    @BeforeTemplate
+    Predicate<String> before() {
+      return s -> !s.isEmpty();
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    Predicate<String> after() {
+      return not(String::isEmpty);
+    }
+  }
+
   /** Prefer {@link Strings#isNullOrEmpty(String)} over the more verbose alternative. */
   static final class StringIsNullOrEmpty {
     @BeforeTemplate
@@ -65,7 +100,7 @@ final class StringRules {
 
     @AfterTemplate
     Optional<String> after(String str) {
-      return Optional.ofNullable(str).filter(s -> !s.isEmpty());
+      return Optional.ofNullable(str).filter(not(String::isEmpty));
     }
   }
 
@@ -76,8 +111,9 @@ final class StringRules {
     }
 
     @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     Optional<String> after(Optional<String> optional) {
-      return optional.filter(s -> !s.isEmpty());
+      return optional.filter(not(String::isEmpty));
     }
   }
 

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/SuggestedFixRules.java

@@ -0,0 +1,106 @@
+package tech.picnic.errorprone.refasterrules;
+
+import com.google.errorprone.fixes.SuggestedFix;
+import com.google.errorprone.refaster.annotation.AfterTemplate;
+import com.google.errorprone.refaster.annotation.BeforeTemplate;
+import com.sun.source.tree.Tree;
+import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
+
+/** Refaster rules related to expressions dealing with {@link SuggestedFix}es. */
+@OnlineDocumentation
+final class SuggestedFixRules {
+  private SuggestedFixRules() {}
+
+  /** Prefer {@link SuggestedFix#delete(Tree)} over more contrived alternatives. */
+  static final class SuggestedFixDelete {
+    @BeforeTemplate
+    SuggestedFix before(Tree tree) {
+      return SuggestedFix.builder().delete(tree).build();
+    }
+
+    @AfterTemplate
+    SuggestedFix after(Tree tree) {
+      return SuggestedFix.delete(tree);
+    }
+  }
+
+  /** Prefer {@link SuggestedFix#replace(Tree, String)}} over more contrived alternatives. */
+  static final class SuggestedFixReplaceTree {
+    @BeforeTemplate
+    SuggestedFix before(Tree tree, String replaceWith) {
+      return SuggestedFix.builder().replace(tree, replaceWith).build();
+    }
+
+    @AfterTemplate
+    SuggestedFix after(Tree tree, String replaceWith) {
+      return SuggestedFix.replace(tree, replaceWith);
+    }
+  }
+
+  /** Prefer {@link SuggestedFix#replace(int, int, String)}} over more contrived alternatives. */
+  static final class SuggestedFixReplaceStartEnd {
+    @BeforeTemplate
+    SuggestedFix before(int start, int end, String replaceWith) {
+      return SuggestedFix.builder().replace(start, end, replaceWith).build();
+    }
+
+    @AfterTemplate
+    SuggestedFix after(int start, int end, String replaceWith) {
+      return SuggestedFix.replace(start, end, replaceWith);
+    }
+  }
+
+  /**
+   * Prefer {@link SuggestedFix#replace(Tree, String, int, int)}} over more contrived alternatives.
+   */
+  static final class SuggestedFixReplaceTreeStartEnd {
+    @BeforeTemplate
+    SuggestedFix before(Tree tree, String replaceWith, int start, int end) {
+      return SuggestedFix.builder().replace(tree, replaceWith, start, end).build();
+    }
+
+    @AfterTemplate
+    SuggestedFix after(Tree tree, String replaceWith, int start, int end) {
+      return SuggestedFix.replace(tree, replaceWith, start, end);
+    }
+  }
+
+  /** Prefer {@link SuggestedFix#swap(Tree, Tree)} over more contrived alternatives. */
+  static final class SuggestedFixSwap {
+    @BeforeTemplate
+    SuggestedFix before(Tree tree1, Tree tree2) {
+      return SuggestedFix.builder().swap(tree1, tree2).build();
+    }
+
+    @AfterTemplate
+    SuggestedFix after(Tree tree1, Tree tree2) {
+      return SuggestedFix.swap(tree1, tree2);
+    }
+  }
+
+  /** Prefer {@link SuggestedFix#prefixWith(Tree, String)} over more contrived alternatives. */
+  static final class SuggestedFixPrefixWith {
+    @BeforeTemplate
+    SuggestedFix before(Tree tree, String prefix) {
+      return SuggestedFix.builder().prefixWith(tree, prefix).build();
+    }
+
+    @AfterTemplate
+    SuggestedFix after(Tree tree, String prefix) {
+      return SuggestedFix.prefixWith(tree, prefix);
+    }
+  }
+
+  /** Prefer {@link SuggestedFix#postfixWith(Tree, String)}} over more contrived alternatives. */
+  static final class SuggestedFixPostfixWith {
+    @BeforeTemplate
+    SuggestedFix before(Tree tree, String postfix) {
+      return SuggestedFix.builder().postfixWith(tree, postfix).build();
+    }
+
+    @AfterTemplate
+    SuggestedFix after(Tree tree, String postfix) {
+      return SuggestedFix.postfixWith(tree, postfix);
+    }
+  }
+}

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/AssertJIsNullTest.java

@@ -1,8 +1,7 @@
 package tech.picnic.errorprone.bugpatterns;
 
-import static com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode.TEXT_MATCH;
-
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
 import com.google.errorprone.CompilationTestHelper;
 import org.junit.jupiter.api.Test;
 
@@ -54,6 +53,6 @@ final class AssertJIsNullTest {
             "    assertThat(\"foo\").isNull();",
             "  }",
             "}")
-        .doTest(TEXT_MATCH);
+        .doTest(TestMode.TEXT_MATCH);
   }
 }

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/AssociativeMethodInvocationTest.java

@@ -0,0 +1,110 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+
+final class AssociativeMethodInvocationTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(AssociativeMethodInvocation.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import com.google.common.collect.ImmutableList;",
+            "import com.google.errorprone.matchers.Matchers;",
+            "import com.google.errorprone.refaster.Refaster;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Matchers.allOf();",
+            "    Matchers.anyOf();",
+            "    Refaster.anyOf();",
+            "",
+            "    Matchers.allOf((t, s) -> true);",
+            "    Matchers.anyOf((t, s) -> true);",
+            "    Refaster.anyOf(0);",
+            "",
+            "    Matchers.allOf(Matchers.anyOf((t, s) -> true));",
+            "    Matchers.anyOf(Matchers.allOf((t, s) -> true));",
+            "    Refaster.anyOf(Matchers.allOf((t, s) -> true));",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    Matchers.allOf(Matchers.allOf((t, s) -> true));",
+            "    // BUG: Diagnostic contains:",
+            "    Matchers.anyOf(Matchers.anyOf((t, s) -> true));",
+            "    // BUG: Diagnostic contains:",
+            "    Refaster.anyOf(Refaster.anyOf(0));",
+            "",
+            "    Matchers.allOf(Matchers.allOf(ImmutableList.of((t, s) -> true)));",
+            "    Matchers.anyOf(Matchers.anyOf(ImmutableList.of((t, s) -> true)));",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    Matchers.allOf(",
+            "        (t, s) -> true, Matchers.allOf((t, s) -> false, (t, s) -> true), (t, s) -> false);",
+            "    // BUG: Diagnostic contains:",
+            "    Matchers.anyOf(",
+            "        (t, s) -> true, Matchers.anyOf((t, s) -> false, (t, s) -> true), (t, s) -> false);",
+            "    // BUG: Diagnostic contains:",
+            "    Refaster.anyOf(0, Refaster.anyOf(1, 2), 3);",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    BugCheckerRefactoringTestHelper.newInstance(AssociativeMethodInvocation.class, getClass())
+        .addInputLines(
+            "A.java",
+            "import com.google.errorprone.matchers.Matchers;",
+            "import com.google.errorprone.refaster.Refaster;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Matchers.allOf(Matchers.allOf());",
+            "    Matchers.anyOf(Matchers.anyOf());",
+            "    Refaster.anyOf(Refaster.anyOf());",
+            "",
+            "    Matchers.allOf(Matchers.allOf((t, s) -> true));",
+            "    Matchers.anyOf(Matchers.anyOf((t, s) -> true));",
+            "    Refaster.anyOf(Refaster.anyOf(0));",
+            "",
+            "    Matchers.allOf(",
+            "        Matchers.anyOf(),",
+            "        Matchers.allOf((t, s) -> false, (t, s) -> true),",
+            "        Matchers.allOf(),",
+            "        Matchers.anyOf((t, s) -> false));",
+            "    Matchers.anyOf(",
+            "        Matchers.allOf(),",
+            "        Matchers.anyOf((t, s) -> false, (t, s) -> true),",
+            "        Matchers.anyOf(),",
+            "        Matchers.allOf((t, s) -> false));",
+            "    Refaster.anyOf(Matchers.allOf(), Refaster.anyOf(1, 2), Matchers.anyOf());",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import com.google.errorprone.matchers.Matchers;",
+            "import com.google.errorprone.refaster.Refaster;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Matchers.allOf();",
+            "    Matchers.anyOf();",
+            "    Refaster.anyOf();",
+            "",
+            "    Matchers.allOf((t, s) -> true);",
+            "    Matchers.anyOf((t, s) -> true);",
+            "    Refaster.anyOf(0);",
+            "",
+            "    Matchers.allOf(",
+            "        Matchers.anyOf(), (t, s) -> false, (t, s) -> true, Matchers.anyOf((t, s) -> false));",
+            "    Matchers.anyOf(",
+            "        Matchers.allOf(), (t, s) -> false, (t, s) -> true, Matchers.allOf((t, s) -> false));",
+            "    Refaster.anyOf(Matchers.allOf(), 1, 2, Matchers.anyOf());",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/CanonicalAnnotationSyntaxTest.java

@@ -34,9 +34,11 @@ final class CanonicalAnnotationSyntaxTest {
             "  // BUG: Diagnostic contains:",
             "  @pkg.A.Foo()",
             "  A functional1();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @A.Foo()",
             "  A functional2();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo()",
             "  A functional3();",
@@ -53,9 +55,11 @@ final class CanonicalAnnotationSyntaxTest {
             "  // BUG: Diagnostic contains:",
             "  @pkg.A.Foo({1})",
             "  A singleton1();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @A.Foo({1})",
             "  A singleton2();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo({1})",
             "  A singleton3();",
@@ -63,9 +67,11 @@ final class CanonicalAnnotationSyntaxTest {
             "  // BUG: Diagnostic contains:",
             "  @pkg.A.Foo(value = 1)",
             "  A verbose1();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @A.Foo(value = 1)",
             "  A verbose2();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo(value = 1)",
             "  A verbose3();",
@@ -82,9 +88,11 @@ final class CanonicalAnnotationSyntaxTest {
             "  // BUG: Diagnostic contains:",
             "  @pkg.A.Foo(value2 = {2})",
             "  A customSingleton1();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @A.Foo(value2 = {2})",
             "  A customSingleton2();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo(value2 = {2})",
             "  A customSingleton3();",
@@ -112,11 +120,13 @@ final class CanonicalAnnotationSyntaxTest {
             "    1, 1,",
             "  })",
             "  A trailingComma1();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @A.Foo({",
             "    1, 1,",
             "  })",
             "  A trailingComma2();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo({",
             "    1, 1,",
@@ -266,4 +276,25 @@ final class CanonicalAnnotationSyntaxTest {
             "}")
         .doTest(TestMode.TEXT_MATCH);
   }
+
+  @Test
+  void ignoreLombokViolations() {
+    CompilationTestHelper.newInstance(CanonicalAnnotationSyntax.class, getClass())
+        .setArgs("-processor", "lombok.launch.AnnotationProcessorHider$AnnotationProcessor")
+        .addSourceLines(
+            "A.java",
+            "import com.fasterxml.jackson.annotation.JsonProperty;",
+            "import lombok.Data;",
+            "",
+            "@Data",
+            "class A {",
+            "  @JsonProperty(\"custom_field_name\")",
+            "  private String field;",
+            "",
+            "  // Should be flagged because of the redundant parentheses, but Lombok doesn't properly link the",
+            "  // annotation to its source code.",
+            "  @JsonProperty() private String field2;",
+            "}")
+        .doTest();
+  }
 }

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/DirectReturnTest.java

@@ -0,0 +1,226 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+
+final class DirectReturnTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(DirectReturn.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import static org.mockito.Mockito.mock;",
+            "import static org.mockito.Mockito.spy;",
+            "",
+            "import java.util.function.Supplier;",
+            "",
+            "class A {",
+            "  private String field;",
+            "",
+            "  void emptyMethod() {}",
+            "",
+            "  void voidMethod() {",
+            "    toString();",
+            "    return;",
+            "  }",
+            "",
+            "  String directReturnOfParam(String param) {",
+            "    return param;",
+            "  }",
+            "",
+            "  String assignmentToField() {",
+            "    field = toString();",
+            "    return field;",
+            "  }",
+            "",
+            "  Object redundantAssignmentToParam(String param) {",
+            "    // BUG: Diagnostic contains:",
+            "    param = toString();",
+            "    return param;",
+            "  }",
+            "",
+            "  String redundantMockAssignmentToParam(String param) {",
+            "    // BUG: Diagnostic contains:",
+            "    param = mock();",
+            "    return param;",
+            "  }",
+            "",
+            "  Object redundantMockWithExplicitTypeAssignmentToParam(String param) {",
+            "    // BUG: Diagnostic contains:",
+            "    param = mock(String.class);",
+            "    return param;",
+            "  }",
+            "",
+            "  Object salientMockAssignmentToParam(String param) {",
+            "    param = mock();",
+            "    return param;",
+            "  }",
+            "",
+            "  String redundantAssignmentToLocalVariable() {",
+            "    String variable = null;",
+            "    // BUG: Diagnostic contains:",
+            "    variable = toString();",
+            "    return variable;",
+            "  }",
+            "",
+            "  String unusedAssignmentToLocalVariable(String param) {",
+            "    String variable = null;",
+            "    variable = toString();",
+            "    return param;",
+            "  }",
+            "",
+            "  String redundantVariableDeclaration() {",
+            "    // BUG: Diagnostic contains:",
+            "    String variable = toString();",
+            "    return variable;",
+            "  }",
+            "",
+            "  String redundantSpyVariableDeclaration() {",
+            "    // BUG: Diagnostic contains:",
+            "    String variable = spy();",
+            "    return variable;",
+            "  }",
+            "",
+            "  Object redundantSpyWithExplicitTypeVariableDeclaration() {",
+            "    // BUG: Diagnostic contains:",
+            "    String variable = spy(String.class);",
+            "    return variable;",
+            "  }",
+            "",
+            "  Object salientSpyTypeVariableDeclaration() {",
+            "    String variable = spy(\"name\");",
+            "    return variable;",
+            "  }",
+            "",
+            "  String unusedVariableDeclaration(String param) {",
+            "    String variable = toString();",
+            "    return param;",
+            "  }",
+            "",
+            "  String assignmentToAnnotatedVariable() {",
+            "    @SuppressWarnings(\"HereBeDragons\")",
+            "    String variable = toString();",
+            "    return variable;",
+            "  }",
+            "",
+            "  String complexReturnStatement() {",
+            "    String variable = toString();",
+            "    return variable + toString();",
+            "  }",
+            "",
+            "  String assignmentInsideIfClause() {",
+            "    String variable = null;",
+            "    if (true) {",
+            "      variable = toString();",
+            "    }",
+            "    return variable;",
+            "  }",
+            "",
+            "  String redundantAssignmentInsideElseClause() {",
+            "    String variable = toString();",
+            "    if (true) {",
+            "      return variable;",
+            "    } else {",
+            "      // BUG: Diagnostic contains:",
+            "      variable = \"foo\";",
+            "      return variable;",
+            "    }",
+            "  }",
+            "",
+            "  Supplier<String> redundantAssignmentInsideLambda() {",
+            "    return () -> {",
+            "      // BUG: Diagnostic contains:",
+            "      String variable = toString();",
+            "      return variable;",
+            "    };",
+            "  }",
+            "",
+            "  String redundantAssignmentInsideTryBlock(AutoCloseable closeable) throws Exception {",
+            "    try (closeable) {",
+            "      // BUG: Diagnostic contains:",
+            "      String variable = toString();",
+            "      return variable;",
+            "    }",
+            "  }",
+            "",
+            "  String redundantAssignmentsInsideTryAndFinallyBlocks() {",
+            "    String variable = toString();",
+            "    try {",
+            "      // BUG: Diagnostic contains:",
+            "      variable = \"foo\";",
+            "      return variable;",
+            "    } finally {",
+            "      String variable2 = toString();",
+            "      if (true) {",
+            "        // BUG: Diagnostic contains:",
+            "        String variable3 = toString();",
+            "        return variable3;",
+            "      }",
+            "      return variable2;",
+            "    }",
+            "  }",
+            "",
+            "  String assignmentUsedInsideFinallyBlock() {",
+            "    String variable = toString();",
+            "    try {",
+            "      variable = \"foo\";",
+            "      return variable;",
+            "    } finally {",
+            "      String variable2 = toString();",
+            "      return variable + variable2;",
+            "    }",
+            "  }",
+            "",
+            "  String redundantAssignmentToVariableUsedInsideUnexecutedFinallyBlock(AutoCloseable closeable)",
+            "      throws Exception {",
+            "    String variable = toString();",
+            "    try (closeable) {",
+            "      if (true) {",
+            "        // BUG: Diagnostic contains:",
+            "        variable = \"foo\";",
+            "        return variable;",
+            "      }",
+            "    }",
+            "    try {",
+            "    } finally {",
+            "      return variable;",
+            "    }",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    BugCheckerRefactoringTestHelper.newInstance(DirectReturn.class, getClass())
+        .addInputLines(
+            "A.java",
+            "class A {",
+            "  String m1() {",
+            "    String variable = null;",
+            "    variable = toString();",
+            "    return variable;",
+            "  }",
+            "",
+            "  String m2() {",
+            "    String variable = toString();",
+            "    return variable;",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "class A {",
+            "  String m1() {",
+            "    String variable = null;",
+            "    return toString();",
+            "  }",
+            "",
+            "  String m2() {",
+            "    return toString();",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/FluxFlatMapUsageTest.java

@@ -67,7 +67,6 @@ final class FluxFlatMapUsageTest {
   @Test
   void replacementFirstSuggestedFix() {
     BugCheckerRefactoringTestHelper.newInstance(FluxFlatMapUsage.class, getClass())
-        .setFixChooser(FixChoosers.FIRST)
         .addInputLines(
             "A.java",
             "import reactor.core.publisher.Flux;",

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/FluxImplicitBlockTest.java

@@ -0,0 +1,182 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.common.base.Predicates.and;
+import static com.google.common.base.Predicates.containsPattern;
+import static com.google.common.base.Predicates.not;
+import static com.google.errorprone.BugCheckerRefactoringTestHelper.FixChoosers.SECOND;
+import static com.google.errorprone.BugCheckerRefactoringTestHelper.FixChoosers.THIRD;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+import org.reactivestreams.Publisher;
+import reactor.core.CorePublisher;
+import reactor.core.publisher.Flux;
+
+final class FluxImplicitBlockTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(FluxImplicitBlock.class, getClass())
+        .expectErrorMessage(
+            "X",
+            and(
+                containsPattern("SuppressWarnings"),
+                containsPattern("toImmutableList"),
+                containsPattern("toList")))
+        .addSourceLines(
+            "A.java",
+            "import com.google.common.collect.ImmutableList;",
+            "import java.util.stream.Stream;",
+            "import reactor.core.publisher.Flux;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    // BUG: Diagnostic matches: X",
+            "    Flux.just(1).toIterable();",
+            "    // BUG: Diagnostic matches: X",
+            "    Flux.just(2).toStream();",
+            "    // BUG: Diagnostic matches: X",
+            "    long count = Flux.just(3).toStream().count();",
+            "",
+            "    Flux.just(4).toIterable(1);",
+            "    Flux.just(5).toIterable(2, null);",
+            "    Flux.just(6).toStream(3);",
+            "    new Foo().toIterable();",
+            "    new Foo().toStream();",
+            "  }",
+            "",
+            "  class Foo<T> {",
+            "    Iterable<T> toIterable() {",
+            "      return ImmutableList.of();",
+            "    }",
+            "",
+            "    Stream<T> toStream() {",
+            "      return Stream.empty();",
+            "    }",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void identificationWithoutGuavaOnClasspath() {
+    CompilationTestHelper.newInstance(FluxImplicitBlock.class, getClass())
+        .withClasspath(CorePublisher.class, Flux.class, Publisher.class)
+        .expectErrorMessage("X", not(containsPattern("toImmutableList")))
+        .addSourceLines(
+            "A.java",
+            "import reactor.core.publisher.Flux;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    // BUG: Diagnostic matches: X",
+            "    Flux.just(1).toIterable();",
+            "    // BUG: Diagnostic matches: X",
+            "    Flux.just(2).toStream();",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacementFirstSuggestedFix() {
+    BugCheckerRefactoringTestHelper.newInstance(FluxImplicitBlock.class, getClass())
+        .addInputLines(
+            "A.java",
+            "import reactor.core.publisher.Flux;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Flux.just(1).toIterable();",
+            "    Flux.just(2).toStream();",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import reactor.core.publisher.Flux;",
+            "",
+            "class A {",
+            "  @SuppressWarnings(\"FluxImplicitBlock\")",
+            "  void m() {",
+            "    Flux.just(1).toIterable();",
+            "    Flux.just(2).toStream();",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+
+  @Test
+  void replacementSecondSuggestedFix() {
+    BugCheckerRefactoringTestHelper.newInstance(FluxImplicitBlock.class, getClass())
+        .setFixChooser(SECOND)
+        .addInputLines(
+            "A.java",
+            "import reactor.core.publisher.Flux;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Flux.just(1).toIterable();",
+            "    Flux.just(2).toStream();",
+            "    Flux.just(3).toIterable().iterator();",
+            "    Flux.just(4).toStream().count();",
+            "    Flux.just(5) /* a */./* b */ toIterable /* c */(/* d */ ) /* e */;",
+            "    Flux.just(6) /* a */./* b */ toStream /* c */(/* d */ ) /* e */;",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import static com.google.common.collect.ImmutableList.toImmutableList;",
+            "",
+            "import reactor.core.publisher.Flux;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Flux.just(1).collect(toImmutableList()).block();",
+            "    Flux.just(2).collect(toImmutableList()).block().stream();",
+            "    Flux.just(3).collect(toImmutableList()).block().iterator();",
+            "    Flux.just(4).collect(toImmutableList()).block().stream().count();",
+            "    Flux.just(5).collect(toImmutableList()).block() /* e */;",
+            "    Flux.just(6).collect(toImmutableList()).block().stream() /* e */;",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+
+  @Test
+  void replacementThirdSuggestedFix() {
+    BugCheckerRefactoringTestHelper.newInstance(FluxImplicitBlock.class, getClass())
+        .setFixChooser(THIRD)
+        .addInputLines(
+            "A.java",
+            "import reactor.core.publisher.Flux;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Flux.just(1).toIterable();",
+            "    Flux.just(2).toStream();",
+            "    Flux.just(3).toIterable().iterator();",
+            "    Flux.just(4).toStream().count();",
+            "    Flux.just(5) /* a */./* b */ toIterable /* c */(/* d */ ) /* e */;",
+            "    Flux.just(6) /* a */./* b */ toStream /* c */(/* d */ ) /* e */;",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import static java.util.stream.Collectors.toList;",
+            "",
+            "import reactor.core.publisher.Flux;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Flux.just(1).collect(toList()).block();",
+            "    Flux.just(2).collect(toList()).block().stream();",
+            "    Flux.just(3).collect(toList()).block().iterator();",
+            "    Flux.just(4).collect(toList()).block().stream().count();",
+            "    Flux.just(5).collect(toList()).block() /* e */;",
+            "    Flux.just(6).collect(toList()).block().stream() /* e */;",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/IdentityConversionTest.java

@@ -180,7 +180,6 @@ final class IdentityConversionTest {
   @Test
   void replacementFirstSuggestedFix() {
     BugCheckerRefactoringTestHelper.newInstance(IdentityConversion.class, getClass())
-        .setFixChooser(FixChoosers.FIRST)
         .addInputLines(
             "A.java",
             "import static com.google.errorprone.matchers.Matchers.staticMethod;",

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/JUnitValueSourceTest.java

@@ -0,0 +1,496 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+
+final class JUnitValueSourceTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(JUnitValueSource.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import static org.junit.jupiter.params.provider.Arguments.arguments;",
+            "",
+            "import java.util.Optional;",
+            "import java.util.stream.Stream;",
+            "import org.junit.jupiter.params.ParameterizedTest;",
+            "import org.junit.jupiter.params.provider.Arguments;",
+            "import org.junit.jupiter.params.provider.MethodSource;",
+            "",
+            "class A {",
+            "  private static Stream<Arguments> identificationTestCases() {",
+            "    return Stream.of(arguments(1), Arguments.of(2));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  // BUG: Diagnostic contains:",
+            "  @MethodSource(\"identificationTestCases\")",
+            "  void identification(int foo) {}",
+            "",
+            "  private static int[] identificationWithParensTestCases() {",
+            "    return new int[] {1, 2};",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  // BUG: Diagnostic contains:",
+            "  @MethodSource(\"identificationWithParensTestCases()\")",
+            "  void identificationWithParens(int foo) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"valueFactoryMissingTestCases\")",
+            "  void valueFactoryMissing(int foo) {}",
+            "",
+            "  private static Stream<Arguments> multipleUsagesTestCases() {",
+            "    return Stream.of(arguments(1), Arguments.of(2));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"multipleUsagesTestCases\")",
+            "  void multipleUsages1(int foo) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"multipleUsagesTestCases()\")",
+            "  void multipleUsages2(int bar) {}",
+            "",
+            "  private static Stream<Arguments> valueFactoryRepeatedTestCases() {",
+            "    return Stream.of(arguments(1), arguments(2));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource({\"valueFactoryRepeatedTestCases\", \"valueFactoryRepeatedTestCases\"})",
+            "  void valueFactoryRepeated(int foo) {}",
+            "",
+            "  private static Stream<Arguments> multipleParametersTestCases() {",
+            "    return Stream.of(arguments(1, 2), arguments(3, 4));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"multipleParametersTestCases\")",
+            "  void multipleParameters(int first, int second) {}",
+            "",
+            "  private static int[] arrayWithoutInitializersTestCases() {",
+            "    return new int[1];",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"arrayWithoutInitializersTestCases\")",
+            "  void arrayWithoutInitializers(int foo) {}",
+            "",
+            "  private static Stream<Arguments> runtimeValueTestCases() {",
+            "    int second = 2;",
+            "    return Stream.of(arguments(1), arguments(second));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"runtimeValueTestCases\")",
+            "  void runtimeValue(int foo) {}",
+            "",
+            "  private static Stream<Arguments> streamChainTestCases() {",
+            "    return Stream.of(1, 2).map(Arguments::arguments);",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"streamChainTestCases\")",
+            "  void streamChain(int number) {}",
+            "",
+            "  private static Stream<Arguments> multipleReturnsTestCases() {",
+            "    if (true) {",
+            "      return Stream.of(arguments(1), arguments(2));",
+            "    } else {",
+            "      return Stream.of(arguments(3), arguments(4));",
+            "    }",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"multipleReturnsTestCases\")",
+            "  void multipleReturns(int number) {}",
+            "",
+            "  private static Stream<Arguments> multipleFactoriesFooTestCases() {",
+            "    return Stream.of(arguments(1));",
+            "  }",
+            "",
+            "  private static Stream<Arguments> multipleFactoriesBarTestCases() {",
+            "    return Stream.of(arguments(1));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource({\"multipleFactoriesFooTestCases\", \"multipleFactoriesBarTestCases\"})",
+            "  void multipleFactories(int i) {}",
+            "",
+            "  private static Stream<Arguments> extraArgsTestCases() {",
+            "    return Stream.of(arguments(1), arguments(1, 2));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"extraArgsTestCases\")",
+            "  void extraArgs(int... i) {}",
+            "",
+            "  private static Stream<Arguments> localClassTestCases() {",
+            "    class Foo {",
+            "      Stream<Arguments> foo() {",
+            "        return Stream.of(arguments(1), arguments(2));",
+            "      }",
+            "    }",
+            "    return Stream.of(arguments(1), arguments(2));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  // BUG: Diagnostic contains:",
+            "  @MethodSource(\"localClassTestCases\")",
+            "  void localClass(int i) {}",
+            "",
+            "  private static Stream<Arguments> lambdaReturnTestCases() {",
+            "    int foo =",
+            "        Optional.of(10)",
+            "            .map(",
+            "                i -> {",
+            "                  return i / 2;",
+            "                })",
+            "            .orElse(0);",
+            "    return Stream.of(arguments(1), arguments(1));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  // BUG: Diagnostic contains:",
+            "  @MethodSource(\"lambdaReturnTestCases\")",
+            "  void lambdaReturn(int i) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"tech.picnic.errorprone.Foo#fooTestCases\")",
+            "  void staticMethodReference(int foo) {}",
+            "",
+            "  private static Stream<Arguments> valueFactoryWithArgumentTestCases(int amount) {",
+            "    return Stream.of(arguments(1), arguments(2));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  // BUG: Diagnostic contains:",
+            "  @MethodSource(\"valueFactoryWithArgumentTestCases\")",
+            "  void valueFactoryWithArgument(int foo) {}",
+            "",
+            "  private static Arguments[] emptyArrayValueFactoryTestCases() {",
+            "    return new Arguments[] {};",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"emptyArrayValueFactoryTestCases\")",
+            "  void emptyArrayValueFactory(int foo) {}",
+            "",
+            "  private static Stream<Arguments> emptyStreamValueFactoryTestCases() {",
+            "    return Stream.of();",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"emptyStreamValueFactoryTestCases\")",
+            "  void emptyStreamValueFactory(int foo) {}",
+            "",
+            "  private static Arguments[] invalidValueFactoryArgumentsTestCases() {",
+            "    return new Arguments[] {arguments(1), arguments(new Object() {})};",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"invalidValueFactoryArgumentsTestCases\")",
+            "  void invalidValueFactoryArguments(int foo) {}",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    BugCheckerRefactoringTestHelper.newInstance(JUnitValueSource.class, getClass())
+        .addInputLines(
+            "A.java",
+            "import static org.junit.jupiter.params.provider.Arguments.arguments;",
+            "",
+            "import com.google.common.collect.ImmutableList;",
+            "import com.google.common.collect.ImmutableSet;",
+            "import java.util.List;",
+            "import java.util.Set;",
+            "import java.util.stream.DoubleStream;",
+            "import java.util.stream.IntStream;",
+            "import java.util.stream.LongStream;",
+            "import java.util.stream.Stream;",
+            "import org.junit.jupiter.params.ParameterizedTest;",
+            "import org.junit.jupiter.params.provider.Arguments;",
+            "import org.junit.jupiter.params.provider.MethodSource;",
+            "",
+            "class A {",
+            "  private static final boolean CONST_BOOLEAN = false;",
+            "  private static final byte CONST_BYTE = 42;",
+            "  private static final char CONST_CHARACTER = 'a';",
+            "  private static final short CONST_SHORT = 42;",
+            "  private static final int CONST_INTEGER = 42;",
+            "  private static final long CONST_LONG = 42;",
+            "  private static final float CONST_FLOAT = 42;",
+            "  private static final double CONST_DOUBLE = 42;",
+            "  private static final String CONST_STRING = \"foo\";",
+            "",
+            "  private static Stream<Arguments> streamOfBooleanArguments() {",
+            "    return Stream.of(arguments(false), arguments(true), arguments(CONST_BOOLEAN));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"streamOfBooleanArguments\")",
+            "  void primitiveBoolean(boolean b) {}",
+            "",
+            "  private static Stream<Object> streamOfBooleansAndBooleanArguments() {",
+            "    return Stream.of(false, arguments(true), CONST_BOOLEAN);",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"streamOfBooleansAndBooleanArguments\")",
+            "  void boxedBoolean(Boolean b) {}",
+            "",
+            "  private static List<Arguments> listOfByteArguments() {",
+            "    return List.of(arguments((byte) 0), arguments((byte) 1), arguments(CONST_BYTE));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"listOfByteArguments\")",
+            "  void primitiveByte(byte b) {}",
+            "",
+            "  private static List<Object> listOfBytesAndByteArguments() {",
+            "    return List.of((byte) 0, arguments((byte) 1), CONST_BYTE);",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"listOfBytesAndByteArguments\")",
+            "  void boxedByte(Byte b) {}",
+            "",
+            "  private static Set<Arguments> setOfCharacterArguments() {",
+            "    return Set.of(arguments((char) 0), arguments((char) 1), arguments(CONST_CHARACTER));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"setOfCharacterArguments\")",
+            "  void primitiveCharacter(char c) {}",
+            "",
+            "  private static Set<Object> setOfCharactersAndCharacterArguments() {",
+            "    return Set.of((char) 0, arguments((char) 1), CONST_CHARACTER);",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"setOfCharactersAndCharacterArguments\")",
+            "  void boxedCharacter(Character c) {}",
+            "",
+            "  private static Arguments[] arrayOfShortArguments() {",
+            "    return new Arguments[] {arguments((short) 0), arguments((short) 1), arguments(CONST_SHORT)};",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"arrayOfShortArguments\")",
+            "  void primitiveShort(short s) {}",
+            "",
+            "  private static Object[] arrayOfShortsAndShortArguments() {",
+            "    return new Object[] {(short) 0, arguments((short) 1), CONST_SHORT};",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"arrayOfShortsAndShortArguments\")",
+            "  void boxedShort(Short s) {}",
+            "",
+            "  private static IntStream intStream() {",
+            "    return IntStream.of(0, 1, CONST_INTEGER);",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"intStream\")",
+            "  void primitiveInteger(int i) {}",
+            "",
+            "  private static int[] intArray() {",
+            "    return new int[] {0, 1, CONST_INTEGER};",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"intArray\")",
+            "  void boxedInteger(Integer i) {}",
+            "",
+            "  private static LongStream longStream() {",
+            "    return LongStream.of(0, 1, CONST_LONG);",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"longStream\")",
+            "  void primitiveLong(long l) {}",
+            "",
+            "  private static long[] longArray() {",
+            "    return new long[] {0, 1, CONST_LONG};",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"longArray\")",
+            "  void boxedLong(Long l) {}",
+            "",
+            "  private static ImmutableList<Arguments> immutableListOfFloatArguments() {",
+            "    return ImmutableList.of(arguments(0.0F), arguments(1.0F), arguments(CONST_FLOAT));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"immutableListOfFloatArguments\")",
+            "  void primitiveFloat(float f) {}",
+            "",
+            "  private static Stream<Object> streamOfFloatsAndFloatArguments() {",
+            "    return Stream.of(0.0F, arguments(1.0F), CONST_FLOAT);",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"streamOfFloatsAndFloatArguments\")",
+            "  void boxedFloat(Float f) {}",
+            "",
+            "  private static DoubleStream doubleStream() {",
+            "    return DoubleStream.of(0, 1, CONST_DOUBLE);",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"doubleStream\")",
+            "  void primitiveDouble(double d) {}",
+            "",
+            "  private static double[] doubleArray() {",
+            "    return new double[] {0, 1, CONST_DOUBLE};",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"doubleArray\")",
+            "  void boxedDouble(Double d) {}",
+            "",
+            "  private static ImmutableSet<Arguments> immutableSetOfStringArguments() {",
+            "    return ImmutableSet.of(arguments(\"foo\"), arguments(\"bar\"), arguments(CONST_STRING));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"immutableSetOfStringArguments\")",
+            "  void string(String s) {}",
+            "",
+            "  private static Stream<Class<?>> streamOfClasses() {",
+            "    return Stream.of(Stream.class, java.util.Map.class);",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"streamOfClasses\")",
+            "  void clazz(Class<?> c) {}",
+            "",
+            "  private static Stream<Arguments> sameNameFactoryTestCases() {",
+            "    return Stream.of(arguments(1));",
+            "  }",
+            "",
+            "  private static Stream<Arguments> sameNameFactoryTestCases(int overload) {",
+            "    return Stream.of(arguments(overload));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @MethodSource(\"sameNameFactoryTestCases\")",
+            "  void sameNameFactory(int i) {}",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import static org.junit.jupiter.params.provider.Arguments.arguments;",
+            "",
+            "import com.google.common.collect.ImmutableList;",
+            "import com.google.common.collect.ImmutableSet;",
+            "import java.util.List;",
+            "import java.util.Set;",
+            "import java.util.stream.DoubleStream;",
+            "import java.util.stream.IntStream;",
+            "import java.util.stream.LongStream;",
+            "import java.util.stream.Stream;",
+            "import org.junit.jupiter.params.ParameterizedTest;",
+            "import org.junit.jupiter.params.provider.Arguments;",
+            "import org.junit.jupiter.params.provider.MethodSource;",
+            "import org.junit.jupiter.params.provider.ValueSource;",
+            "",
+            "class A {",
+            "  private static final boolean CONST_BOOLEAN = false;",
+            "  private static final byte CONST_BYTE = 42;",
+            "  private static final char CONST_CHARACTER = 'a';",
+            "  private static final short CONST_SHORT = 42;",
+            "  private static final int CONST_INTEGER = 42;",
+            "  private static final long CONST_LONG = 42;",
+            "  private static final float CONST_FLOAT = 42;",
+            "  private static final double CONST_DOUBLE = 42;",
+            "  private static final String CONST_STRING = \"foo\";",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(booleans = {false, true, CONST_BOOLEAN})",
+            "  void primitiveBoolean(boolean b) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(booleans = {false, true, CONST_BOOLEAN})",
+            "  void boxedBoolean(Boolean b) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(bytes = {(byte) 0, (byte) 1, CONST_BYTE})",
+            "  void primitiveByte(byte b) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(bytes = {(byte) 0, (byte) 1, CONST_BYTE})",
+            "  void boxedByte(Byte b) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(chars = {(char) 0, (char) 1, CONST_CHARACTER})",
+            "  void primitiveCharacter(char c) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(chars = {(char) 0, (char) 1, CONST_CHARACTER})",
+            "  void boxedCharacter(Character c) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(shorts = {(short) 0, (short) 1, CONST_SHORT})",
+            "  void primitiveShort(short s) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(shorts = {(short) 0, (short) 1, CONST_SHORT})",
+            "  void boxedShort(Short s) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(ints = {0, 1, CONST_INTEGER})",
+            "  void primitiveInteger(int i) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(ints = {0, 1, CONST_INTEGER})",
+            "  void boxedInteger(Integer i) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(longs = {0, 1, CONST_LONG})",
+            "  void primitiveLong(long l) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(longs = {0, 1, CONST_LONG})",
+            "  void boxedLong(Long l) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(floats = {0.0F, 1.0F, CONST_FLOAT})",
+            "  void primitiveFloat(float f) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(floats = {0.0F, 1.0F, CONST_FLOAT})",
+            "  void boxedFloat(Float f) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(doubles = {0, 1, CONST_DOUBLE})",
+            "  void primitiveDouble(double d) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(doubles = {0, 1, CONST_DOUBLE})",
+            "  void boxedDouble(Double d) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(strings = {\"foo\", \"bar\", CONST_STRING})",
+            "  void string(String s) {}",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(classes = {Stream.class, java.util.Map.class})",
+            "  void clazz(Class<?> c) {}",
+            "",
+            "  private static Stream<Arguments> sameNameFactoryTestCases(int overload) {",
+            "    return Stream.of(arguments(overload));",
+            "  }",
+            "",
+            "  @ParameterizedTest",
+            "  @ValueSource(ints = 1)",
+            "  void sameNameFactory(int i) {}",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/LexicographicalAnnotationAttributeListingTest.java

@@ -50,18 +50,21 @@ final class LexicographicalAnnotationAttributeListingTest {
             "",
             "  @Foo({\"a\", \"b\"})",
             "  A sortedStrings();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo({\"b\", \"a\"})",
             "  A unsortedString();",
             "",
             "  @Foo({\"ab\", \"Ac\"})",
             "  A sortedStringCaseInsensitive();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo({\"ac\", \"Ab\"})",
             "  A unsortedStringCaseInsensitive();",
             "",
             "  @Foo({\"A\", \"a\"})",
             "  A sortedStringCaseInsensitiveWithTotalOrderFallback();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo({\"a\", \"A\"})",
             "  A unsortedStringCaseInsensitiveWithTotalOrderFallback();",
@@ -86,6 +89,7 @@ final class LexicographicalAnnotationAttributeListingTest {
             "",
             "  @Foo(cls = {int.class, long.class})",
             "  A sortedClasses();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo(cls = {long.class, int.class})",
             "  A unsortedClasses();",
@@ -98,6 +102,7 @@ final class LexicographicalAnnotationAttributeListingTest {
             "",
             "  @Foo(enums = {DOWN, UP})",
             "  A sortedEnums();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo(enums = {UP, DOWN})",
             "  A unsortedEnums();",
@@ -110,15 +115,18 @@ final class LexicographicalAnnotationAttributeListingTest {
             "",
             "  @Foo(anns = {@Bar(\"a\"), @Bar(\"b\")})",
             "  A sortedAnns();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo(anns = {@Bar(\"b\"), @Bar(\"a\")})",
             "  A unsortedAnns();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo(anns = {@Bar(\"a\"), @Bar({\"b\", \"a\"})})",
             "  A unsortedInnderAnns();",
             "",
             "  @Foo({\"a=foo\", \"a.b=bar\", \"a.c=baz\"})",
             "  A hierarchicallySorted();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo({\"a.b=bar\", \"a.c=baz\", \"a=foo\"})",
             "  A hierarchicallyUnsorted();",
@@ -265,12 +273,14 @@ final class LexicographicalAnnotationAttributeListingTest {
             "  // BUG: Diagnostic contains:",
             "  @Foo({\"b\", \"a\"})",
             "  A fooValue();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo(value2 = {\"b\", \"a\"})",
             "  A fooValue2();",
             "",
             "  @Bar({\"b\", \"a\"})",
             "  A barValue();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Bar(value2 = {\"b\", \"a\"})",
             "  A barValue2();",

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/LexicographicalAnnotationListingTest.java

@@ -52,6 +52,7 @@ final class LexicographicalAnnotationListingTest {
             "  @Foo",
             "  @Bar",
             "  A unsortedSimpleCase();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo()",
             "  @Bar()",
@@ -69,6 +70,7 @@ final class LexicographicalAnnotationListingTest {
             "  @Baz",
             "  @Bar",
             "  A threeUnsortedAnnotationsSameInitialLetter();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Bar",
             "  @Foo()",
@@ -84,11 +86,13 @@ final class LexicographicalAnnotationListingTest {
             "  @Foo({\"b\"})",
             "  @Bar({\"a\"})",
             "  A unsortedWithStringAttributes();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Baz(str = {\"a\", \"b\"})",
             "  @Foo(ints = {1, 0})",
             "  @Bar",
             "  A unsortedWithAttributes();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Bar",
             "  @Foo(anns = {@Bar(\"b\"), @Bar(\"a\")})",
@@ -104,6 +108,7 @@ final class LexicographicalAnnotationListingTest {
             "  @Foo(ints = {1, 2})",
             "  @Foo({\"b\"})",
             "  A sortedRepeatableAnnotation();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @Foo(anns = {@Bar(\"b\"), @Bar(\"a\")})",
             "  @Bar",

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/MissingRefasterAnnotationTest.java

@@ -1,89 +0,0 @@
-package tech.picnic.errorprone.bugpatterns;
-
-import static com.google.common.base.Predicates.containsPattern;
-
-import com.google.errorprone.CompilationTestHelper;
-import org.junit.jupiter.api.Test;
-
-final class MissingRefasterAnnotationTest {
-  @Test
-  void identification() {
-    CompilationTestHelper.newInstance(MissingRefasterAnnotation.class, getClass())
-        .expectErrorMessage(
-            "X",
-            containsPattern("The Refaster rule contains a method without any Refaster annotations"))
-        .addSourceLines(
-            "A.java",
-            "import com.google.errorprone.refaster.annotation.AfterTemplate;",
-            "import com.google.errorprone.refaster.annotation.AlsoNegation;",
-            "import com.google.errorprone.refaster.annotation.BeforeTemplate;",
-            "import java.util.Map;",
-            "",
-            "class A {",
-            "  // BUG: Diagnostic matches: X",
-            "  static final class MethodLacksBeforeTemplateAnnotation {",
-            "    @BeforeTemplate",
-            "    boolean before1(String string) {",
-            "      return string.equals(\"\");",
-            "    }",
-            "",
-            "    // @BeforeTemplate is missing",
-            "    boolean before2(String string) {",
-            "      return string.length() == 0;",
-            "    }",
-            "",
-            "    @AfterTemplate",
-            "    @AlsoNegation",
-            "    boolean after(String string) {",
-            "      return string.isEmpty();",
-            "    }",
-            "  }",
-            "",
-            "  // BUG: Diagnostic matches: X",
-            "  static final class MethodLacksAfterTemplateAnnotation {",
-            "    @BeforeTemplate",
-            "    boolean before(String string) {",
-            "      return string.equals(\"\");",
-            "    }",
-            "",
-            "    // @AfterTemplate is missing",
-            "    boolean after(String string) {",
-            "      return string.isEmpty();",
-            "    }",
-            "  }",
-            "",
-            "  // BUG: Diagnostic matches: X",
-            "  abstract class MethodLacksPlaceholderAnnotation<K, V> {",
-            "    // @Placeholder is missing",
-            "    abstract V function(K key);",
-            "",
-            "    @BeforeTemplate",
-            "    void before(Map<K, V> map, K key) {",
-            "      if (!map.containsKey(key)) {",
-            "        map.put(key, function(key));",
-            "      }",
-            "    }",
-            "",
-            "    @AfterTemplate",
-            "    void after(Map<K, V> map, K key) {",
-            "      map.computeIfAbsent(key, k -> function(k));",
-            "    }",
-            "  }",
-            "",
-            "  static final class ValidRefasterRule {",
-            "    @BeforeTemplate",
-            "    void unusedPureFunctionCall(Object o) {",
-            "      o.toString();",
-            "    }",
-            "  }",
-            "",
-            "  static final class NotARefasterRule {",
-            "    @Override",
-            "    public String toString() {",
-            "      return \"This is not a Refaster rule\";",
-            "    }",
-            "  }",
-            "}")
-        .doTest();
-  }
-}

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/MockitoMockClassReferenceTest.java

@@ -0,0 +1,136 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+
+final class MockitoMockClassReferenceTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(MockitoMockClassReference.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import static org.mockito.Mockito.mock;",
+            "import static org.mockito.Mockito.spy;",
+            "import static org.mockito.Mockito.withSettings;",
+            "",
+            "import java.util.List;",
+            "import java.util.Objects;",
+            "import org.mockito.invocation.InvocationOnMock;",
+            "",
+            "class A {",
+            "  {",
+            "    Double d = Objects.requireNonNullElseGet(null, () -> mock(Double.class));",
+            "    Double d2 =",
+            "        Objects.requireNonNullElseGet(",
+            "            null,",
+            "            () -> {",
+            "              return mock(Double.class);",
+            "            });",
+            "  }",
+            "",
+            "  void m() {",
+            "    Number variableMock = 42;",
+            "    // BUG: Diagnostic contains:",
+            "    variableMock = mock(Number.class);",
+            "    // BUG: Diagnostic contains:",
+            "    variableMock = mock(Number.class, \"name\");",
+            "    // BUG: Diagnostic contains:",
+            "    variableMock = mock(Number.class, InvocationOnMock::callRealMethod);",
+            "    // BUG: Diagnostic contains:",
+            "    variableMock = mock(Number.class, withSettings());",
+            "    variableMock = mock(Integer.class);",
+            "    variableMock = 42;",
+            "    // BUG: Diagnostic contains:",
+            "    List rawMock = mock(List.class);",
+            "    // BUG: Diagnostic contains:",
+            "    List<String> genericMock = mock(List.class);",
+            "    var varMock = mock(Integer.class);",
+            "    Class<? extends Number> numberType = Integer.class;",
+            "    Number variableTypeMock = mock(numberType);",
+            "    Object subtypeMock = mock(Integer.class);",
+            "",
+            "    Number variableSpy = 42;",
+            "    // BUG: Diagnostic contains:",
+            "    variableSpy = spy(Number.class);",
+            "    variableSpy = spy(Integer.class);",
+            "    variableSpy = 42;",
+            "    // BUG: Diagnostic contains:",
+            "    List rawSpy = spy(List.class);",
+            "    // BUG: Diagnostic contains:",
+            "    List<String> genericSpy = spy(List.class);",
+            "    var varSpy = spy(Integer.class);",
+            "    Number variableTypeSpy = spy(numberType);",
+            "    Object subtypeSpy = spy(Integer.class);",
+            "    Object objectSpy = spy(new Object());",
+            "",
+            "    Objects.hash(mock(Integer.class));",
+            "    Integer i = mock(mock(Integer.class));",
+            "    String s = new String(mock(String.class));",
+            "  }",
+            "",
+            "  Double getDoubleMock() {",
+            "    return Objects.requireNonNullElseGet(",
+            "        null,",
+            "        () -> {",
+            "          return mock(Double.class);",
+            "        });",
+            "  }",
+            "",
+            "  Integer getIntegerMock() {",
+            "    // BUG: Diagnostic contains:",
+            "    return mock(Integer.class);",
+            "  }",
+            "",
+            "  <T> T getGenericMock(Class<T> clazz) {",
+            "    return mock(clazz);",
+            "  }",
+            "",
+            "  Number getSubTypeMock() {",
+            "    return mock(Integer.class);",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    BugCheckerRefactoringTestHelper.newInstance(MockitoMockClassReference.class, getClass())
+        .addInputLines(
+            "A.java",
+            "import static org.mockito.Mockito.mock;",
+            "import static org.mockito.Mockito.spy;",
+            "import static org.mockito.Mockito.withSettings;",
+            "",
+            "import org.mockito.invocation.InvocationOnMock;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Number simpleMock = mock(Number.class);",
+            "    Number namedMock = mock(Number.class, \"name\");",
+            "    Number customAnswerMock = mock(Number.class, InvocationOnMock::callRealMethod);",
+            "    Number customSettingsMock = mock(Number.class, withSettings());",
+            "    Number simpleSpy = spy(Number.class);",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import static org.mockito.Mockito.mock;",
+            "import static org.mockito.Mockito.spy;",
+            "import static org.mockito.Mockito.withSettings;",
+            "",
+            "import org.mockito.invocation.InvocationOnMock;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Number simpleMock = mock();",
+            "    Number namedMock = mock(\"name\");",
+            "    Number customAnswerMock = mock(InvocationOnMock::callRealMethod);",
+            "    Number customSettingsMock = mock(withSettings());",
+            "    Number simpleSpy = spy();",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/MongoDBTextFilterUsageTest.java

@@ -0,0 +1,26 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+
+final class MongoDBTextFilterUsageTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(MongoDBTextFilterUsage.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import com.mongodb.client.model.Filters;",
+            "import com.mongodb.client.model.TextSearchOptions;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Filters.eq(\"foo\", \"bar\");",
+            "    // BUG: Diagnostic contains:",
+            "    Filters.text(\"foo\");",
+            "    // BUG: Diagnostic contains:",
+            "    Filters.text(\"foo\", new TextSearchOptions());",
+            "  }",
+            "}")
+        .doTest();
+  }
+}

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/NestedOptionalsTest.java

@@ -36,19 +36,4 @@ final class NestedOptionalsTest {
             "}")
         .doTest();
   }
-
-  @Test
-  void identificationOptionalTypeNotLoaded() {
-    CompilationTestHelper.newInstance(NestedOptionals.class, getClass())
-        .addSourceLines(
-            "A.java",
-            "import java.time.Duration;",
-            "",
-            "class A {",
-            "  void m() {",
-            "    Duration.ofSeconds(1);",
-            "  }",
-            "}")
-        .doTest();
-  }
 }

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/NestedPublishersTest.java

@@ -0,0 +1,37 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+
+final class NestedPublishersTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(NestedPublishers.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import org.reactivestreams.Publisher;",
+            "import reactor.core.publisher.Flux;",
+            "import reactor.core.publisher.GroupedFlux;",
+            "import reactor.core.publisher.Mono;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Mono.empty();",
+            "    Flux.just(1);",
+            "    Flux.just(1, 2).groupBy(i -> i).map(groupedFlux -> (GroupedFlux) groupedFlux);",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    Mono.just(Mono.empty());",
+            "    // BUG: Diagnostic contains:",
+            "    Flux.just(Flux.empty());",
+            "    // BUG: Diagnostic contains:",
+            "    Mono.just((Flux) Flux.just(1));",
+            "    // BUG: Diagnostic contains:",
+            "    Flux.just((Publisher) Mono.just(1));",
+            "    // BUG: Diagnostic contains:",
+            "    Mono.just(1).map(Mono::just);",
+            "  }",
+            "}")
+        .doTest();
+  }
+}

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/NonEmptyMonoTest.java

@@ -1,8 +1,7 @@
 package tech.picnic.errorprone.bugpatterns;
 
-import static com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode.TEXT_MATCH;
-
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
 import com.google.errorprone.CompilationTestHelper;
 import org.junit.jupiter.api.Test;
 
@@ -145,6 +144,6 @@ final class NonEmptyMonoTest {
             "    Mono.just(2).hasElement();",
             "  }",
             "}")
-        .doTest(TEXT_MATCH);
+        .doTest(TestMode.TEXT_MATCH);
   }
 }

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RedundantStringConversionTest.java

@@ -10,12 +10,9 @@ import org.junit.jupiter.api.Test;
 // `String.valueOf(null)` may not. That is because the latter matches `String#valueOf(char[])`. We
 // could special-case `null` arguments, but that doesn't seem worth the trouble.
 final class RedundantStringConversionTest {
-  private final CompilationTestHelper compilationTestHelper =
-      CompilationTestHelper.newInstance(RedundantStringConversion.class, getClass());
-
   @Test
   void identificationOfIdentityTransformation() {
-    compilationTestHelper
+    CompilationTestHelper.newInstance(RedundantStringConversion.class, getClass())
         .addSourceLines(
             "A.java",
             "class A {",
@@ -38,7 +35,7 @@ final class RedundantStringConversionTest {
 
   @Test
   void identificationWithinMutatingAssignment() {
-    compilationTestHelper
+    CompilationTestHelper.newInstance(RedundantStringConversion.class, getClass())
         .addSourceLines(
             "A.java",
             "import java.math.BigInteger;",
@@ -99,7 +96,7 @@ final class RedundantStringConversionTest {
 
   @Test
   void identificationWithinBinaryOperation() {
-    compilationTestHelper
+    CompilationTestHelper.newInstance(RedundantStringConversion.class, getClass())
         .addSourceLines(
             "A.java",
             "import java.math.BigInteger;",
@@ -194,7 +191,7 @@ final class RedundantStringConversionTest {
 
   @Test
   void identificationWithinStringBuilderMethod() {
-    compilationTestHelper
+    CompilationTestHelper.newInstance(RedundantStringConversion.class, getClass())
         .addSourceLines(
             "A.java",
             "import java.math.BigInteger;",
@@ -249,7 +246,7 @@ final class RedundantStringConversionTest {
   // XXX: Also test the other formatter methods.
   @Test
   void identificationWithinFormatterMethod() {
-    compilationTestHelper
+    CompilationTestHelper.newInstance(RedundantStringConversion.class, getClass())
         .addSourceLines(
             "A.java",
             "import java.util.Formattable;",
@@ -294,7 +291,7 @@ final class RedundantStringConversionTest {
 
   @Test
   void identificationWithinGuavaGuardMethod() {
-    compilationTestHelper
+    CompilationTestHelper.newInstance(RedundantStringConversion.class, getClass())
         .addSourceLines(
             "A.java",
             "import static com.google.common.base.Preconditions.checkArgument;",
@@ -354,7 +351,7 @@ final class RedundantStringConversionTest {
 
   @Test
   void identificationWithinSlf4jLoggerMethod() {
-    compilationTestHelper
+    CompilationTestHelper.newInstance(RedundantStringConversion.class, getClass())
         .addSourceLines(
             "A.java",
             "import java.util.Formattable;",

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RequestMappingAnnotationTest.java

@@ -9,13 +9,15 @@ final class RequestMappingAnnotationTest {
     CompilationTestHelper.newInstance(RequestMappingAnnotation.class, getClass())
         .addSourceLines(
             "A.java",
+            "import jakarta.servlet.http.HttpServletRequest;",
+            "import jakarta.servlet.http.HttpServletResponse;",
             "import java.io.InputStream;",
             "import java.time.ZoneId;",
             "import java.util.Locale;",
             "import java.util.TimeZone;",
-            "import javax.servlet.http.HttpServletRequest;",
-            "import javax.servlet.http.HttpServletResponse;",
             "import org.springframework.http.HttpMethod;",
+            "import org.springframework.ui.Model;",
+            "import org.springframework.validation.BindingResult;",
             "import org.springframework.web.bind.annotation.DeleteMapping;",
             "import org.springframework.web.bind.annotation.GetMapping;",
             "import org.springframework.web.bind.annotation.PatchMapping;",
@@ -82,6 +84,12 @@ final class RequestMappingAnnotationTest {
             "  A properHttpMethod(HttpMethod method);",
             "",
             "  @RequestMapping",
+            "  A properModel(Model model);",
+            "",
+            "  @RequestMapping",
+            "  A properBindingResult(BindingResult result);",
+            "",
+            "  @RequestMapping",
             "  A properNativeWebRequest(NativeWebRequest request);",
             "",
             "  @RequestMapping",

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/SpringMvcAnnotationTest.java

@@ -32,18 +32,23 @@ final class SpringMvcAnnotationTest {
             "",
             "  @RequestMapping(method = {})",
             "  A explicitDefault();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @RequestMapping(method = RequestMethod.GET)",
             "  A get();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @RequestMapping(method = {RequestMethod.POST})",
             "  A post();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @RequestMapping(method = {PUT})",
             "  A put();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @RequestMapping(method = {DELETE})",
             "  A delete();",
+            "",
             "  // BUG: Diagnostic contains:",
             "  @RequestMapping(method = {PATCH})",
             "  A patch();",

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/StringCaseLocaleUsageTest.java

@@ -1,125 +0,0 @@
-package tech.picnic.errorprone.bugpatterns;
-
-import com.google.errorprone.BugCheckerRefactoringTestHelper;
-import com.google.errorprone.BugCheckerRefactoringTestHelper.FixChoosers;
-import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
-import com.google.errorprone.CompilationTestHelper;
-import org.junit.jupiter.api.Test;
-
-final class StringCaseLocaleUsageTest {
-  @Test
-  void identification() {
-    CompilationTestHelper.newInstance(StringCaseLocaleUsage.class, getClass())
-        .addSourceLines(
-            "A.java",
-            "import static java.util.Locale.ROOT;",
-            "",
-            "import java.util.Locale;",
-            "",
-            "class A {",
-            "  void m() {",
-            "    \"a\".toLowerCase(Locale.ROOT);",
-            "    \"a\".toUpperCase(Locale.ROOT);",
-            "    \"b\".toLowerCase(ROOT);",
-            "    \"b\".toUpperCase(ROOT);",
-            "    \"c\".toLowerCase(Locale.getDefault());",
-            "    \"c\".toUpperCase(Locale.getDefault());",
-            "    \"d\".toLowerCase(Locale.ENGLISH);",
-            "    \"d\".toUpperCase(Locale.ENGLISH);",
-            "    \"e\".toLowerCase(new Locale(\"foo\"));",
-            "    \"e\".toUpperCase(new Locale(\"foo\"));",
-            "",
-            "    // BUG: Diagnostic contains:",
-            "    \"f\".toLowerCase();",
-            "    // BUG: Diagnostic contains:",
-            "    \"g\".toUpperCase();",
-            "",
-            "    String h = \"h\";",
-            "    // BUG: Diagnostic contains:",
-            "    h.toLowerCase();",
-            "    String i = \"i\";",
-            "    // BUG: Diagnostic contains:",
-            "    i.toUpperCase();",
-            "  }",
-            "}")
-        .doTest();
-  }
-
-  @Test
-  void replacementFirstSuggestedFix() {
-    BugCheckerRefactoringTestHelper.newInstance(StringCaseLocaleUsage.class, getClass())
-        .setFixChooser(FixChoosers.FIRST)
-        .addInputLines(
-            "A.java",
-            "class A {",
-            "  void m() {",
-            "    \"a\".toLowerCase(/* Comment with parens: (). */ );",
-            "    \"b\".toUpperCase();",
-            "    \"c\".toLowerCase().toString();",
-            "",
-            "    toString().toLowerCase();",
-            "    toString().toUpperCase /* Comment with parens: (). */();",
-            "",
-            "    this.toString().toLowerCase() /* Comment with parens: (). */;",
-            "    this.toString().toUpperCase();",
-            "  }",
-            "}")
-        .addOutputLines(
-            "A.java",
-            "import java.util.Locale;",
-            "",
-            "class A {",
-            "  void m() {",
-            "    \"a\".toLowerCase(/* Comment with parens: (). */ Locale.ROOT);",
-            "    \"b\".toUpperCase(Locale.ROOT);",
-            "    \"c\".toLowerCase(Locale.ROOT).toString();",
-            "",
-            "    toString().toLowerCase(Locale.ROOT);",
-            "    toString().toUpperCase /* Comment with parens: (). */(Locale.ROOT);",
-            "",
-            "    this.toString().toLowerCase(Locale.ROOT) /* Comment with parens: (). */;",
-            "    this.toString().toUpperCase(Locale.ROOT);",
-            "  }",
-            "}")
-        .doTest(TestMode.TEXT_MATCH);
-  }
-
-  @Test
-  void replacementSecondSuggestedFix() {
-    BugCheckerRefactoringTestHelper.newInstance(StringCaseLocaleUsage.class, getClass())
-        .setFixChooser(FixChoosers.SECOND)
-        .addInputLines(
-            "A.java",
-            "class A {",
-            "  void m() {",
-            "    \"a\".toLowerCase();",
-            "    \"b\".toUpperCase(/* Comment with parens: (). */ );",
-            "    \"c\".toLowerCase().toString();",
-            "",
-            "    toString().toLowerCase();",
-            "    toString().toUpperCase /* Comment with parens: (). */();",
-            "",
-            "    this.toString().toLowerCase() /* Comment with parens: (). */;",
-            "    this.toString().toUpperCase();",
-            "  }",
-            "}")
-        .addOutputLines(
-            "A.java",
-            "import java.util.Locale;",
-            "",
-            "class A {",
-            "  void m() {",
-            "    \"a\".toLowerCase(Locale.getDefault());",
-            "    \"b\".toUpperCase(/* Comment with parens: (). */ Locale.getDefault());",
-            "    \"c\".toLowerCase(Locale.getDefault()).toString();",
-            "",
-            "    toString().toLowerCase(Locale.getDefault());",
-            "    toString().toUpperCase /* Comment with parens: (). */(Locale.getDefault());",
-            "",
-            "    this.toString().toLowerCase(Locale.getDefault()) /* Comment with parens: (). */;",
-            "    this.toString().toUpperCase(Locale.getDefault());",
-            "  }",
-            "}")
-        .doTest(TestMode.TEXT_MATCH);
-  }
-}