Merge branch 'master' into website

This new `Extractor` implementation collects Refaster example input and 
output code from rule collection tests.

This change also introduces explicit compilation steps for the test
code. As a side-effect this produces faster feedback in case of invalid
input or output code.

.github/release.yml

@@ -3,16 +3,16 @@ changelog:
     labels:
       - "ignore-changelog"
   categories:
+    - title: ":warning: Update considerations and deprecations"
+      labels:
+        - "breaking change"
+        - "deprecation"
     - title: ":rocket: New Error Prone checks and Refaster rules"
       labels:
         - "new feature"
     - title: ":sparkles: Improvements"
       labels:
         - "improvement"
-    - title: ":warning: Update considerations and deprecations"
-      labels:
-        - "breaking change"
-        - "deprecation"
     - title: ":bug: Bug fixes"
       labels:
         - "bug"

.github/workflows/build.yml

@@ -10,7 +10,7 @@ jobs:
     strategy:
       matrix:
         os: [ ubuntu-22.04 ]
-        jdk: [ 17.0.10, 21.0.2 ]
+        jdk: [ 17.0.10, 21.0.2, 22.0.2 ]
         distribution: [ temurin ]
         experimental: [ false ]
         include:
@@ -25,17 +25,28 @@ jobs:
     runs-on: ${{ matrix.os }}
     continue-on-error: ${{ matrix.experimental }}
     steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@f086349bfa2bd1361f7909c78558e816508cdc10 # v2.8.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            api.adoptium.net:443
+            github.com:443
+            jitpack.io:443
+            objects.githubusercontent.com:443
+            repo.maven.apache.org:443
       # 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 and set up JDK and Maven
-        uses: s4u/setup-maven-action@6d44c18d67d9e1549907b8815efa5e4dada1801b # v1.12.0
+        uses: s4u/setup-maven-action@489441643219d2b93ee2a127b2402eb640a1b947 # v1.13.0
         with:
           java-version: ${{ matrix.jdk }}
           java-distribution: ${{ matrix.distribution }}
-          maven-version: 3.9.6
+          maven-version: 3.9.9
       - name: Display build environment details
         run: mvn --version
       - name: Build project against vanilla Error Prone, compile Javadoc

.github/workflows/codeql.yml

@@ -21,20 +21,32 @@ jobs:
       security-events: write
     runs-on: ubuntu-22.04
     steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@f086349bfa2bd1361f7909c78558e816508cdc10 # v2.8.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            api.adoptium.net:443
+            api.github.com:443
+            github.com:443
+            objects.githubusercontent.com:443
+            repo.maven.apache.org:443
+            uploads.github.com:443
       - name: Check out code and set up JDK and Maven
-        uses: s4u/setup-maven-action@6d44c18d67d9e1549907b8815efa5e4dada1801b # v1.12.0
+        uses: s4u/setup-maven-action@489441643219d2b93ee2a127b2402eb640a1b947 # v1.13.0
         with:
           java-version: 17.0.10
           java-distribution: temurin
-          maven-version: 3.9.6
+          maven-version: 3.9.9
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@b7bf0a3ed3ecfa44160715d7c442788f65f0f923 # v3.23.2
+        uses: github/codeql-action/init@c7f9125735019aa87cfc361530512d50ea439c71 # v3.25.1
         with:
           languages: ${{ matrix.language }}
       - name: Perform minimal build
         if: matrix.language == 'java'
         run: mvn -T1C clean package -DskipTests -Dverification.skip
       - name: Perform CodeQL analysis
-        uses: github/codeql-action/analyze@b7bf0a3ed3ecfa44160715d7c442788f65f0f923 # v3.23.2
+        uses: github/codeql-action/analyze@c7f9125735019aa87cfc361530512d50ea439c71 # v3.25.1
         with:
           category: /language:${{ matrix.language }}

.github/workflows/deploy-website.yml

@@ -11,26 +11,56 @@ jobs:
   build:
     runs-on: ubuntu-22.04
     steps:
-      - name: Check out code
-        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@f086349bfa2bd1361f7909c78558e816508cdc10 # v2.8.0
         with:
-          persist-credentials: false
-      - uses: ruby/setup-ruby@bd03e04863f52d169e18a2b190e8fa6b84938215 # v1.170.0
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            api.adoptium.net:443
+            api.github.com:443
+            bestpractices.coreinfrastructure.org:443
+            blog.picnic.nl:443
+            errorprone.info:443
+            github.com:443
+            img.shields.io:443
+            index.rubygems.org:443
+            jitpack.io:443
+            maven.apache.org:443
+            objects.githubusercontent.com:443
+            pitest.org:443
+            repo.maven.apache.org:443
+            rubygems.org:443
+            search.maven.org:443
+            securityscorecards.dev:443
+            sonarcloud.io:443
+            www.baeldung.com:443
+            www.bestpractices.dev:443
+            www.youtube.com:443
+            youtrack.jetbrains.com:443
+      - name: Check out code and set up JDK and Maven
+        uses: s4u/setup-maven-action@489441643219d2b93ee2a127b2402eb640a1b947 # v1.13.0
+        with:
+          java-version: 17.0.10
+          java-distribution: temurin
+          maven-version: 3.9.6
+      - uses: ruby/setup-ruby@6bd3d993c602f6b675728ebaecb2b569ff86e99b # v1.174.0
         with:
           working-directory: ./website
           bundler-cache: true
       - name: Configure Github Pages
-        uses: actions/configure-pages@1f0c5cde4bc74cd7e1254d0cb4de8d49e9068c7d # v4.0.0
+        uses: actions/configure-pages@983d7736d9b0ae728b81ab479565c72886d7745b # v5.0.0
+      - name: Compile project and extract data
+        run: mvn -T1C clean install -DskipTests -Dverification.skip
       - name: Generate documentation
-        run: ./generate-docs.sh
+        run: mvn exec:java@generate-docs -pl documentation-support
       - name: Build website with Jekyll
         working-directory: ./website
         run: bundle exec jekyll build
       - name: Validate HTML output
         working-directory: ./website
-        # XXX: Drop `--disable_external true` once we fully adopted the
-        # "Refaster rules" terminology on our website and in the code.
-        run: bundle exec htmlproofer --disable_external true --check-external-hash false ./_site
+        # XXX: StackOverflow returns a 403 when run on GHA.
+        run: bundle exec htmlproofer --no-check-external-hash --swap-url 'https\://error-prone.picnic.tech:' --ignore-urls '/^https:\/\/stackoverflow.com\/.*/' ./_site
       - name: Upload website as artifact
         uses: actions/upload-pages-artifact@56afc609e74202658d3ffba0e8f6dda462b719fa # v3.0.1
         with:
@@ -46,6 +76,13 @@ jobs:
       name: github-pages
       url: ${{ steps.deployment.outputs.page_url }}
     steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@f086349bfa2bd1361f7909c78558e816508cdc10 # v2.8.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            api.github.com:443
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@decdde0ac072f6dcbe43649d82d9c635fff5b4e4 # v4.0.4
+        uses: actions/deploy-pages@d6db90164ac5ed86f2b6aed7e0febac5b3c0c03e # v4.0.5

.github/workflows/openssf-scorecard.yml

@@ -20,17 +20,31 @@ jobs:
       id-token: write
     runs-on: ubuntu-22.04
     steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@f086349bfa2bd1361f7909c78558e816508cdc10 # v2.8.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            api.github.com:443
+            api.osv.dev:443
+            api.scorecard.dev:443
+            api.securityscorecards.dev:443
+            github.com:443
+            oss-fuzz-build-logs.storage.googleapis.com:443
+            *.sigstore.dev:443
+            www.bestpractices.dev:443
       - name: Check out code
-        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+        uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29 # v4.1.6
         with:
           persist-credentials: false
       - name: Run OpenSSF Scorecard analysis
-        uses: ossf/scorecard-action@0864cf19026789058feabb7e87baa5f140aac736 # v2.3.1
+        uses: ossf/scorecard-action@dc50aa9510b46c811795eb24b2f1ba02a914e534 # v2.3.3
         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@b7bf0a3ed3ecfa44160715d7c442788f65f0f923 # v3.23.2
+        uses: github/codeql-action/upload-sarif@c7f9125735019aa87cfc361530512d50ea439c71 # v3.25.1
         with:
           sarif_file: results.sarif

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

@@ -11,13 +11,23 @@ jobs:
   analyze-pr:
     runs-on: ubuntu-22.04
     steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@f086349bfa2bd1361f7909c78558e816508cdc10 # v2.8.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            api.adoptium.net:443
+            github.com:443
+            objects.githubusercontent.com:443
+            repo.maven.apache.org:443
       - name: Check out code and set up JDK and Maven
-        uses: s4u/setup-maven-action@6d44c18d67d9e1549907b8815efa5e4dada1801b # v1.12.0
+        uses: s4u/setup-maven-action@489441643219d2b93ee2a127b2402eb640a1b947 # v1.13.0
         with:
           checkout-fetch-depth: 2
           java-version: 17.0.10
           java-distribution: temurin
-          maven-version: 3.9.6
+          maven-version: 3.9.9
       - name: Run Pitest
         # By running with features `+GIT(from[HEAD~1]), +gitci`, Pitest only
         # analyzes lines changed in the associated pull request, as GitHub
@@ -28,7 +38,7 @@ 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@5d5d22a31266ced268874388b861e4b58bb5c2f3 # v4.3.1
+        uses: actions/upload-artifact@65462800fd760344b1a7b4382951275a0abb4808 # v4.3.3
         with:
           name: pitest-reports
           path: ./target/pit-reports-ci

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

@@ -19,14 +19,25 @@ jobs:
       pull-requests: write
     runs-on: ubuntu-22.04
     steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@f086349bfa2bd1361f7909c78558e816508cdc10 # v2.8.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            api.adoptium.net:443
+            api.github.com:443
+            github.com:443
+            objects.githubusercontent.com:443
+            repo.maven.apache.org:443
       - name: Check out code and set up JDK and Maven
-        uses: s4u/setup-maven-action@6d44c18d67d9e1549907b8815efa5e4dada1801b # v1.12.0
+        uses: s4u/setup-maven-action@489441643219d2b93ee2a127b2402eb640a1b947 # v1.13.0
         with:
           java-version: 17.0.10
           java-distribution: temurin
-          maven-version: 3.9.6
+          maven-version: 3.9.9
       - name: Download Pitest analysis artifact
-        uses: dawidd6/action-download-artifact@72aaadce3bc708349fc665eee3785cbb1b6e51d0 # v3.1.1
+        uses: dawidd6/action-download-artifact@09f2f74827fd3a8607589e5ad7f9398816f540fe # v3.1.4
         with:
           workflow: ${{ github.event.workflow_run.workflow_id }}
           name: pitest-reports

.github/workflows/run-integration-tests.yml

@@ -18,20 +18,34 @@ jobs:
       github.event.issue.pull_request && contains(github.event.comment.body, '/integration-test')
     runs-on: ubuntu-22.04
     steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@f086349bfa2bd1361f7909c78558e816508cdc10 # v2.8.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            api.adoptium.net:443
+            checkstyle.org:443
+            github.com:443
+            objects.githubusercontent.com:443
+            oss.sonatype.org:443
+            raw.githubusercontent.com:443
+            repo.maven.apache.org:443
+            repository.sonatype.org:443
       - name: Check out code and set up JDK and Maven
-        uses: s4u/setup-maven-action@6d44c18d67d9e1549907b8815efa5e4dada1801b # v1.12.0
+        uses: s4u/setup-maven-action@489441643219d2b93ee2a127b2402eb640a1b947 # v1.13.0
         with:
           checkout-ref: "refs/pull/${{ github.event.issue.number }}/head"
           java-version: 17.0.10
           java-distribution: temurin
-          maven-version: 3.9.6
+          maven-version: 3.9.9
       - name: Install project to local Maven repository
         run: mvn -T1C install -DskipTests -Dverification.skip
       - name: Run integration test
         run: xvfb-run ./integration-tests/checkstyle.sh "${{ runner.temp }}/artifacts"
       - name: Upload artifacts on failure
         if: ${{ failure() }}
-        uses: actions/upload-artifact@5d5d22a31266ced268874388b861e4b58bb5c2f3 # v4.3.1
+        uses: actions/upload-artifact@65462800fd760344b1a7b4382951275a0abb4808 # v4.3.3
         with:
           name: integration-test-checkstyle
           path: "${{ runner.temp }}/artifacts"

.github/workflows/sonarcloud.yml

@@ -18,13 +18,29 @@ jobs:
       contents: read
     runs-on: ubuntu-22.04
     steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@f086349bfa2bd1361f7909c78558e816508cdc10 # v2.8.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            analysis-sensorcache-eu-central-1-prod.s3.amazonaws.com:443
+            api.adoptium.net:443
+            api.nuget.org:443
+            ea6ne4j2sb.execute-api.eu-central-1.amazonaws.com:443
+            github.com:443
+            objects.githubusercontent.com:443
+            repo.maven.apache.org:443
+            sc-cleancode-sensorcache-eu-central-1-prod.s3.amazonaws.com:443
+            *.sonarcloud.io:443
+            sonarcloud.io:443
       - name: Check out code and set up JDK and Maven
-        uses: s4u/setup-maven-action@6d44c18d67d9e1549907b8815efa5e4dada1801b # v1.12.0
+        uses: s4u/setup-maven-action@489441643219d2b93ee2a127b2402eb640a1b947 # v1.13.0
         with:
           checkout-fetch-depth: 0
           java-version: 17.0.10
           java-distribution: temurin
-          maven-version: 3.9.6
+          maven-version: 3.9.9
       - name: Create missing `test` directory
         # XXX: Drop this step in favour of actually having a test.
         run: mkdir refaster-compiler/src/test

.gitignore

@@ -4,6 +4,7 @@
 .DS_Store
 .factorypath
 .idea
+!.idea/icon.svg
 .project
 .settings
 target

.idea/icon.svg

@@ -0,0 +1,65 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg width="100%" height="100%" viewBox="0 0 1259 1199" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve" xmlns:serif="http://www.serif.com/" style="fill-rule:evenodd;clip-rule:evenodd;stroke-linejoin:round;stroke-miterlimit:2;">
+    <g transform="matrix(1,0,0,1,-624.154,-988.431)">
+        <g transform="matrix(1,0,0,1,-70.1122,-35.0561)">
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1227.03,1988.79C1237.78,2070.45 1225.83,2190.1 1192.24,2194.53C1158.65,2198.95 1116.14,2086.46 1105.39,2004.81C1094.64,1923.16 1128.44,1902.11 1153.32,1898.84C1178.18,1895.56 1216.28,1907.14 1227.03,1988.79Z" style="fill:rgb(219,220,211);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1151.08,1881.86C1134.93,1883.99 1114.77,1892.69 1101.6,1913.17C1088.42,1933.64 1082.71,1963.73 1088.42,2007.04C1094.04,2049.75 1107.59,2099.16 1124.51,2138.68C1132.97,2158.45 1142.15,2175.68 1152.59,2188.86C1163.04,2202.05 1176.31,2213.89 1194.48,2211.5C1212.65,2209.11 1222.39,2194.23 1229.07,2178.8C1235.75,2163.36 1240.15,2144.34 1243.21,2123.05C1249.32,2080.5 1249.63,2029.27 1244,1986.56C1238.3,1943.24 1225,1915.66 1206.98,1899.29C1188.95,1882.93 1167.22,1879.74 1151.08,1881.86ZM1155.55,1915.81C1164.27,1914.66 1174.03,1915.62 1183.96,1924.64C1193.89,1933.66 1205.01,1952.69 1210.06,1991.03C1215.18,2029.97 1214.89,2079.4 1209.32,2118.19C1206.53,2137.58 1202.32,2154.4 1197.65,2165.2C1194.14,2173.29 1190.82,2176.3 1189.96,2177.22C1188.89,2176.55 1184.91,2174.51 1179.43,2167.6C1172.12,2158.38 1163.7,2143.22 1155.99,2125.21C1140.57,2089.18 1127.49,2041.51 1122.36,2002.57C1117.32,1964.24 1123.13,1942.97 1130.39,1931.69C1137.65,1920.42 1146.82,1916.96 1155.55,1915.81Z" style="fill:rgb(26,26,26);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1516.33,1963.1C1466.19,1897.75 1427.4,1906.77 1407.5,1922.05C1387.59,1937.32 1368.84,1972.45 1418.98,2037.8C1431.75,2054.44 1447.26,2071.84 1463.69,2088.19C1495.18,2119.52 1534.33,2139.39 1582.98,2126.14C1606.4,2119.76 1622.19,2110.46 1623.75,2098.64C1625.79,2083.16 1603,2065.78 1569.69,2050.47C1554.75,2019.83 1535.59,1988.2 1516.33,1963.1Z" style="fill:rgb(219,220,211);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1397.07,1908.46C1409.99,1898.55 1430.41,1890.44 1454.2,1895.61C1478,1900.77 1503.31,1918 1529.91,1952.67C1548.92,1977.44 1567.3,2007.65 1582.28,2037.56C1597.47,2044.87 1610.74,2052.64 1621.09,2061.47C1632.68,2071.35 1642.93,2084.12 1640.73,2100.88C1639.05,2113.64 1630.31,2122.66 1620.9,2128.78C1611.49,2134.9 1600.29,2139.17 1587.48,2142.66C1532.39,2157.66 1485.57,2134.11 1451.61,2100.32C1434.7,2083.49 1418.73,2065.6 1405.39,2048.22C1378.79,2013.56 1368.69,1984.64 1369.86,1960.32C1371.04,1936 1384.15,1918.38 1397.07,1908.46ZM1417.92,1935.63C1410.94,1940.99 1404.71,1948.57 1404.07,1961.97C1403.43,1975.37 1409.02,1996.69 1432.56,2027.38C1444.76,2043.27 1459.82,2060.18 1475.77,2076.05C1504.8,2104.93 1536.26,2121.12 1578.48,2109.62C1589.1,2106.73 1597.5,2103.16 1602.23,2100.08C1605.14,2098.18 1606.16,2096.97 1606.54,2096.46C1606.07,2095.66 1604.57,2092.39 1598.86,2087.52C1591.24,2081.02 1578.31,2073.28 1562.54,2066.03L1556.98,2063.47L1554.29,2057.97C1539.86,2028.35 1521.12,1997.46 1502.75,1973.52C1479.2,1942.84 1460.05,1931.91 1446.94,1929.07C1433.84,1926.23 1424.9,1930.27 1417.92,1935.63Z" style="fill:rgb(26,26,26);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M917.121,1633.14C845.801,1674.32 730.68,1709.07 713.738,1679.73C696.797,1650.39 784.453,1568.07 855.777,1526.89C927.102,1485.71 959.48,1508.89 972.02,1530.62C984.562,1552.34 988.445,1591.97 917.121,1633.14Z" style="fill:rgb(219,220,211);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M986.848,1522.06C978.707,1507.95 962.949,1492.66 938.992,1488.32C915.031,1483.98 885.055,1490.22 847.219,1512.07C809.906,1533.61 769.453,1565.03 739.41,1595.79C724.391,1611.17 711.977,1626.24 703.797,1640.94C695.617,1655.64 689.746,1672.42 698.914,1688.29C708.078,1704.17 725.547,1707.48 742.363,1707.74C759.184,1708.01 778.445,1704.79 799.273,1699.47C840.934,1688.83 888.375,1669.51 925.684,1647.97C963.52,1626.12 983.91,1603.29 992.137,1580.37C1000.36,1557.45 994.988,1536.16 986.848,1522.06ZM957.195,1539.18C961.594,1546.79 964.438,1556.18 959.906,1568.8C955.379,1581.43 942.047,1598.98 908.562,1618.32C874.551,1637.96 828.77,1656.6 790.801,1666.3C771.816,1671.14 754.664,1673.69 742.902,1673.5C734.082,1673.37 730.035,1671.45 728.859,1671C729.062,1669.76 729.426,1665.3 733.715,1657.59C739.434,1647.31 750.215,1633.73 763.906,1619.72C791.285,1591.68 830.324,1561.36 864.336,1541.72C897.824,1522.38 919.695,1519.62 932.895,1522.01C946.09,1524.4 952.797,1531.56 957.195,1539.18Z" style="fill:rgb(26,26,26);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1791.57,1526.89C1862.89,1568.07 1950.54,1650.39 1933.61,1679.74C1916.66,1709.08 1801.54,1674.33 1730.22,1633.15C1658.9,1591.97 1662.78,1552.34 1675.32,1530.62C1687.86,1508.89 1720.24,1485.72 1791.57,1526.89Z" style="fill:rgb(219,220,211);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1660.5,1522.06C1652.35,1536.16 1646.98,1557.45 1655.21,1580.37C1663.43,1603.29 1683.82,1626.13 1721.66,1647.97C1758.97,1669.52 1806.41,1688.84 1848.07,1699.48C1868.9,1704.79 1888.16,1708.01 1904.98,1707.75C1921.79,1707.48 1939.27,1704.17 1948.43,1688.3C1957.59,1672.42 1951.73,1655.64 1943.55,1640.94C1935.37,1626.25 1922.95,1611.17 1907.93,1595.79C1877.89,1565.04 1837.43,1533.61 1800.12,1512.07C1762.29,1490.22 1732.31,1483.98 1708.35,1488.32C1684.39,1492.66 1668.64,1507.95 1660.5,1522.06ZM1690.15,1539.18C1694.55,1531.56 1701.25,1524.4 1714.45,1522.02C1727.64,1519.62 1749.52,1522.39 1783,1541.72C1817.02,1561.36 1856.06,1591.68 1883.44,1619.72C1897.12,1633.73 1907.91,1647.32 1913.63,1657.59C1917.92,1665.3 1918.28,1669.77 1918.48,1671.01C1917.31,1671.45 1913.26,1673.37 1904.44,1673.51C1892.68,1673.69 1875.52,1671.15 1856.54,1666.3C1818.57,1656.61 1772.79,1637.96 1738.78,1618.32C1705.29,1598.99 1691.97,1581.43 1687.43,1568.81C1682.91,1556.18 1685.75,1546.8 1690.15,1539.18Z" style="fill:rgb(26,26,26);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1322.81,1013.67C1058.16,1014.17 843.293,1229.45 843.297,1494.11L843.223,1862.19C843.223,1955.32 919.055,2031.16 1012.19,2031.16C1054.55,2031.16 1093.39,2015.51 1123.09,1989.7C1169.54,2049.44 1242.17,2087.79 1323.7,2087.79C1405.22,2087.79 1477.84,2049.45 1524.28,1989.73C1553.98,2015.52 1592.81,2031.16 1635.15,2031.16C1728.29,2031.16 1804.12,1955.32 1804.12,1862.19L1804.12,1494.1C1804.12,1229.09 1588.7,1013.67 1323.69,1013.67L1322.84,1013.67L1322.81,1013.67ZM1322.92,1068.46L1323.69,1068.46C1559.09,1068.46 1749.33,1258.7 1749.33,1494.11L1749.33,1862.19C1749.33,1925.92 1698.88,1976.37 1635.15,1976.37C1596.91,1976.37 1563.67,1958.03 1542.94,1929.68L1517.91,1895.48L1497,1932.34C1462.85,1992.53 1398.48,2033 1323.7,2033C1248.9,2033 1184.52,1992.51 1150.38,1932.3L1129.45,1895.41L1104.43,1929.65C1083.69,1958.02 1050.44,1976.37 1012.19,1976.37C948.461,1976.37 898.016,1925.93 898.012,1862.2L898.086,1494.11C898.086,1259.03 1087.84,1068.92 1322.92,1068.47L1322.92,1068.46Z" style="fill:rgb(26,26,26);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1322.86,1041.07C1072.99,1041.54 870.684,1244.23 870.688,1494.11L870.648,1862.19C870.648,1940.62 933.789,2003.77 1012.22,2003.77C1073.65,2003.77 1125.69,1965.03 1145.37,1910.56C1201.73,1934.69 1262.41,1947.14 1323.72,1947.14C1385.02,1947.14 1445.69,1934.69 1502.04,1910.57C1521.72,1965.04 1573.76,2003.77 1635.19,2003.77C1713.62,2003.77 1776.76,1940.62 1776.76,1862.19L1776.76,1494.11C1776.76,1243.9 1573.93,1041.07 1323.72,1041.07L1322.86,1041.07Z" style="fill:white;fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1323.7,1494.1C1449.2,1494.1 1550.24,1595.14 1550.24,1720.64L1550.24,1833.86C1550.24,1959.36 1449.2,2060.4 1323.7,2060.4C1198.2,2060.4 1097.16,1959.36 1097.16,1833.86L1097.16,1720.64C1097.16,1595.14 1198.2,1494.1 1323.7,1494.1Z" style="fill:white;fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1322.86,1041.07C1262.14,1041.18 1204.25,1053.27 1151.36,1075.05C1316.07,1142.87 1432.03,1304.93 1432.03,1494.11L1432.03,1811.95C1432.03,2003.63 1209.62,2024.85 1126.54,1945.82C1177.52,2034.1 1254.55,2060.4 1323.7,2060.4C1408.4,2060.4 1481.95,2014.37 1520.82,1945.86C1546.53,1981.01 1588.08,2003.77 1635.15,2003.77C1713.58,2003.77 1776.72,1940.62 1776.72,1862.19L1776.72,1494.11C1776.72,1243.9 1573.89,1041.07 1323.68,1041.07L1322.86,1041.07Z" style="fill:rgb(219,220,211);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1322.86,1041.07C1304.33,1041.1 1286.06,1042.28 1268.11,1044.48C1492.04,1071.93 1665.46,1262.75 1665.46,1494.11L1665.46,1862.19C1665.46,1920.85 1630.14,1970.94 1579.54,1992.48C1596.59,1999.74 1615.38,2003.77 1635.15,2003.77C1713.58,2003.77 1776.72,1940.62 1776.72,1862.19L1776.72,1494.11C1776.72,1243.9 1573.89,1041.07 1323.68,1041.07L1322.86,1041.07Z" style="fill:rgb(189,191,175);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1322.85,1034.22C1069.29,1034.69 863.84,1240.54 863.84,1494.11L863.766,1862.19C863.766,1944.3 930.078,2010.61 1012.19,2010.61C1057.88,2010.61 1098.53,1989.94 1125.71,1957.58C1166.88,2023.5 1240.02,2067.25 1323.7,2067.25C1407.36,2067.25 1480.48,2023.52 1521.66,1957.62C1548.84,1989.96 1589.47,2010.61 1635.15,2010.61C1717.25,2010.61 1783.57,1944.3 1783.57,1862.19L1783.57,1494.11C1783.57,1240.2 1577.59,1034.21 1323.68,1034.22L1322.85,1034.22ZM1322.86,1047.92L1323.68,1047.92C1570.19,1047.92 1769.87,1247.6 1769.87,1494.11L1769.87,1862.19C1769.87,1936.95 1709.91,1996.92 1635.15,1996.92C1590.29,1996.92 1550.82,1975.26 1526.36,1941.82L1520.1,1933.27L1514.87,1942.48C1477.18,2008.91 1405.92,2053.55 1323.7,2053.55C1241.46,2053.55 1170.19,2008.89 1132.5,1942.44L1127.27,1933.21L1121.02,1941.77C1096.56,1975.24 1057.07,1996.92 1012.19,1996.92C937.43,1996.92 877.469,1936.95 877.465,1862.19L877.539,1494.11C877.539,1247.94 1076.7,1048.39 1322.86,1047.92Z" style="fill:rgb(26,26,26);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1576.29,1470.72C1576.29,1481.36 1568.75,1491.56 1555.31,1499.08C1541.88,1506.6 1523.67,1510.83 1504.68,1510.83C1465.12,1510.83 1433.06,1492.87 1433.06,1470.72C1433.06,1448.57 1465.12,1430.62 1504.68,1430.62C1523.67,1430.62 1541.88,1434.84 1555.31,1442.36C1568.75,1449.89 1576.29,1460.09 1576.29,1470.72Z" style="fill:rgb(255,155,173);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1214.28,1470.72C1214.28,1481.36 1206.73,1491.56 1193.31,1499.08C1179.87,1506.6 1161.66,1510.83 1142.66,1510.83C1103.11,1510.83 1071.05,1492.87 1071.05,1470.72C1071.05,1448.57 1103.11,1430.62 1142.66,1430.62C1161.66,1430.62 1179.87,1434.84 1193.31,1442.36C1206.73,1449.89 1214.28,1460.09 1214.28,1470.72Z" style="fill:rgb(255,155,173);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1104.39,1401.46C1104.39,1375.15 1118.45,1350.79 1141.24,1337.63C1164.03,1324.48 1192.16,1324.48 1214.95,1337.63C1237.74,1350.79 1251.81,1375.15 1251.81,1401.46L1224.41,1401.46C1224.41,1384.9 1215.6,1369.64 1201.25,1361.36C1186.9,1353.07 1169.29,1353.07 1154.94,1361.36C1140.59,1369.64 1131.78,1384.9 1131.78,1401.46L1104.39,1401.46Z" style="fill:rgb(26,26,26);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1395.54,1401.46C1395.54,1375.15 1409.61,1350.79 1432.39,1337.63C1455.18,1324.48 1483.32,1324.48 1506.11,1337.63C1528.89,1350.79 1542.96,1375.15 1542.96,1401.46L1515.56,1401.46C1515.56,1384.9 1506.75,1369.64 1492.41,1361.36C1478.06,1353.07 1460.44,1353.07 1446.09,1361.36C1431.74,1369.64 1422.93,1384.9 1422.93,1401.46L1395.54,1401.46Z" style="fill:rgb(26,26,26);fill-rule:nonzero;"/>
+            </g>
+            <g transform="matrix(1,0,0,1,0,9.81959)">
+                <path d="M1256.81,1448.61C1256.81,1472.48 1269.56,1494.57 1290.24,1506.51C1310.92,1518.45 1336.42,1518.45 1357.1,1506.51C1377.78,1494.57 1390.53,1472.48 1390.53,1448.61L1376.83,1448.61C1376.83,1467.61 1366.71,1485.15 1350.25,1494.65C1333.79,1504.15 1313.55,1504.15 1297.09,1494.65C1280.63,1485.15 1270.51,1467.61 1270.51,1448.61L1256.81,1448.61Z" style="fill:rgb(26,26,26);fill-rule:nonzero;"/>
+            </g>
+        </g>
+    </g>
+</svg>

.renovaterc.json

@@ -12,7 +12,8 @@
       "separateMinorPatch": true
     },
     {
-      "matchDepNames": [
+      "matchPackageNames": [
+        "dawidd6/action-download-artifact",
         "github/codeql-action",
         "ruby/setup-ruby"
       ],

documentation-support/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.15.1-SNAPSHOT</version>
+        <version>0.18.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>documentation-support</artifactId>
@@ -33,14 +33,31 @@
             <artifactId>error_prone_test_helpers</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>error-prone-utils</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>refaster-test-support</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-annotations</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-core</artifactId>
+        </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-yaml</artifactId>
+        </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.datatype</groupId>
             <artifactId>jackson-datatype-guava</artifactId>
@@ -67,6 +84,10 @@
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.github.java-diff-utils</groupId>
+            <artifactId>java-diff-utils</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.assertj</groupId>
             <artifactId>assertj-core</artifactId>
@@ -95,4 +116,29 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
+
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.codehaus.mojo</groupId>
+                    <artifactId>exec-maven-plugin</artifactId>
+                    <executions>
+                        <execution>
+                            <id>generate-docs</id>
+                            <goals>
+                                <goal>java</goal>
+                            </goals>
+                            <configuration>
+                                <mainClass>tech.picnic.errorprone.documentation.JekyllCollectionGenerator</mainClass>
+                                <arguments>
+                                    <argument>${maven.multiModuleProjectDirectory}</argument>
+                                </arguments>
+                            </configuration>
+                        </execution>
+                    </executions>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
 </project>

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

@@ -27,7 +27,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
 import org.jspecify.annotations.Nullable;
-import tech.picnic.errorprone.documentation.BugPatternTestExtractor.TestCases;
+import tech.picnic.errorprone.documentation.BugPatternTestExtractor.BugPatternTestCases;
 
 /**
  * An {@link Extractor} that describes how to extract data from classes that test a {@code
@@ -40,7 +40,7 @@ import tech.picnic.errorprone.documentation.BugPatternTestExtractor.TestCases;
 @Immutable
 @AutoService(Extractor.class)
 @SuppressWarnings("rawtypes" /* See https://github.com/google/auto/issues/870. */)
-public final class BugPatternTestExtractor implements Extractor<TestCases> {
+public final class BugPatternTestExtractor implements Extractor<BugPatternTestCases> {
   /** Instantiates a new {@link BugPatternTestExtractor} instance. */
   public BugPatternTestExtractor() {}
 
@@ -50,7 +50,7 @@ public final class BugPatternTestExtractor implements Extractor<TestCases> {
   }
 
   @Override
-  public Optional<TestCases> tryExtract(ClassTree tree, VisitorState state) {
+  public Optional<BugPatternTestCases> tryExtract(ClassTree tree, VisitorState state) {
     BugPatternTestCollector collector = new BugPatternTestCollector();
 
     collector.scan(tree, state);
@@ -59,7 +59,7 @@ public final class BugPatternTestExtractor implements Extractor<TestCases> {
         .filter(not(ImmutableList::isEmpty))
         .map(
             tests ->
-                new AutoValue_BugPatternTestExtractor_TestCases(
+                new AutoValue_BugPatternTestExtractor_BugPatternTestCases(
                     state.getPath().getCompilationUnit().getSourceFile().toUri(),
                     ASTHelpers.getSymbol(tree).className(),
                     tests));
@@ -95,10 +95,10 @@ public final class BugPatternTestExtractor implements Extractor<TestCases> {
             .onDescendantOf("com.google.errorprone.BugCheckerRefactoringTestHelper.ExpectOutput")
             .namedAnyOf("addOutputLines", "expectUnchanged");
 
-    private final List<TestCase> collectedTestCases = new ArrayList<>();
+    private final List<BugPatternTestCase> collectedBugPatternTestCases = new ArrayList<>();
 
-    private ImmutableList<TestCase> getCollectedTests() {
-      return ImmutableList.copyOf(collectedTestCases);
+    private ImmutableList<BugPatternTestCase> getCollectedTests() {
+      return ImmutableList.copyOf(collectedBugPatternTestCases);
     }
 
     @Override
@@ -110,14 +110,14 @@ public final class BugPatternTestExtractor implements Extractor<TestCases> {
                 classUnderTest -> {
                   List<TestEntry> entries = new ArrayList<>();
                   if (isReplacementTest) {
-                    extractReplacementTestCases(node, entries, state);
+                    extractReplacementBugPatternTestCases(node, entries, state);
                   } else {
-                    extractIdentificationTestCases(node, entries, state);
+                    extractIdentificationBugPatternTestCases(node, entries, state);
                   }
 
                   if (!entries.isEmpty()) {
-                    collectedTestCases.add(
-                        new AutoValue_BugPatternTestExtractor_TestCase(
+                    collectedBugPatternTestCases.add(
+                        new AutoValue_BugPatternTestExtractor_BugPatternTestCase(
                             classUnderTest, ImmutableList.copyOf(entries).reverse()));
                   }
                 });
@@ -140,7 +140,7 @@ public final class BugPatternTestExtractor implements Extractor<TestCases> {
           : Optional.empty();
     }
 
-    private static void extractIdentificationTestCases(
+    private static void extractIdentificationBugPatternTestCases(
         MethodInvocationTree tree, List<TestEntry> sink, VisitorState state) {
       if (IDENTIFICATION_SOURCE_LINES.matches(tree, state)) {
         String path = ASTHelpers.constValue(tree.getArguments().get(0), String.class);
@@ -155,11 +155,11 @@ public final class BugPatternTestExtractor implements Extractor<TestCases> {
 
       ExpressionTree receiver = ASTHelpers.getReceiver(tree);
       if (receiver instanceof MethodInvocationTree methodInvocation) {
-        extractIdentificationTestCases(methodInvocation, sink, state);
+        extractIdentificationBugPatternTestCases(methodInvocation, sink, state);
       }
     }
 
-    private static void extractReplacementTestCases(
+    private static void extractReplacementBugPatternTestCases(
         MethodInvocationTree tree, List<TestEntry> sink, VisitorState state) {
       if (REPLACEMENT_OUTPUT_SOURCE_LINES.matches(tree, state)) {
         /*
@@ -185,7 +185,7 @@ public final class BugPatternTestExtractor implements Extractor<TestCases> {
 
       ExpressionTree receiver = ASTHelpers.getReceiver(tree);
       if (receiver instanceof MethodInvocationTree methodInvocation) {
-        extractReplacementTestCases(methodInvocation, sink, state);
+        extractReplacementBugPatternTestCases(methodInvocation, sink, state);
       }
     }
 
@@ -208,24 +208,26 @@ public final class BugPatternTestExtractor implements Extractor<TestCases> {
   }
 
   @AutoValue
-  @JsonDeserialize(as = AutoValue_BugPatternTestExtractor_TestCases.class)
-  abstract static class TestCases {
-    static TestCases create(URI source, String testClass, ImmutableList<TestCase> testCases) {
-      return new AutoValue_BugPatternTestExtractor_TestCases(source, testClass, testCases);
+  @JsonDeserialize(as = AutoValue_BugPatternTestExtractor_BugPatternTestCases.class)
+  abstract static class BugPatternTestCases {
+    static BugPatternTestCases create(
+        URI source, String testClass, ImmutableList<BugPatternTestCase> testCases) {
+      return new AutoValue_BugPatternTestExtractor_BugPatternTestCases(
+          source, testClass, testCases);
     }
 
     abstract URI source();
 
     abstract String testClass();
 
-    abstract ImmutableList<TestCase> testCases();
+    abstract ImmutableList<BugPatternTestCase> testCases();
   }
 
   @AutoValue
-  @JsonDeserialize(as = AutoValue_BugPatternTestExtractor_TestCase.class)
-  abstract static class TestCase {
-    static TestCase create(String classUnderTest, ImmutableList<TestEntry> entries) {
-      return new AutoValue_BugPatternTestExtractor_TestCase(classUnderTest, entries);
+  @JsonDeserialize(as = AutoValue_BugPatternTestExtractor_BugPatternTestCase.class)
+  abstract static class BugPatternTestCase {
+    static BugPatternTestCase create(String classUnderTest, ImmutableList<TestEntry> entries) {
+      return new AutoValue_BugPatternTestExtractor_BugPatternTestCase(classUnderTest, entries);
     }
 
     abstract String classUnderTest();

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

@@ -14,7 +14,6 @@ import java.io.IOException;
 import java.net.URI;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.ServiceLoader;
 import javax.tools.JavaFileObject;
 
@@ -87,6 +86,6 @@ final class DocumentationGeneratorTaskListener implements TaskListener {
   }
 
   private static String getSimpleClassName(URI path) {
-    return Paths.get(path).getFileName().toString().replace(".java", "");
+    return Path.of(path).getFileName().toString().replace(".java", "");
   }
 }

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

@@ -0,0 +1,332 @@
+package tech.picnic.errorprone.documentation;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.collect.ImmutableList.toImmutableList;
+import static com.google.common.collect.ImmutableListMultimap.flatteningToImmutableListMultimap;
+import static com.google.common.collect.ImmutableMap.toImmutableMap;
+import static com.google.common.collect.ImmutableTable.toImmutableTable;
+import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.util.Objects.requireNonNull;
+import static java.util.stream.Collectors.joining;
+
+import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;
+import com.fasterxml.jackson.annotation.PropertyAccessor;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.dataformat.yaml.YAMLGenerator;
+import com.fasterxml.jackson.dataformat.yaml.YAMLMapper;
+import com.github.difflib.DiffUtils;
+import com.github.difflib.UnifiedDiffUtils;
+import com.github.difflib.patch.Patch;
+import com.google.auto.value.AutoValue;
+import com.google.common.base.Function;
+import com.google.common.base.Splitter;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableListMultimap;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableTable;
+import com.google.common.collect.Sets;
+import com.google.errorprone.BugPattern.SeverityLevel;
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.nio.file.FileSystems;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.PathMatcher;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.ArrayList;
+import java.util.List;
+import org.jspecify.annotations.Nullable;
+import tech.picnic.errorprone.documentation.BugPatternExtractor.BugPatternDocumentation;
+import tech.picnic.errorprone.documentation.BugPatternTestExtractor.BugPatternTestCase;
+import tech.picnic.errorprone.documentation.BugPatternTestExtractor.BugPatternTestCases;
+import tech.picnic.errorprone.documentation.BugPatternTestExtractor.IdentificationTestEntry;
+import tech.picnic.errorprone.documentation.BugPatternTestExtractor.ReplacementTestEntry;
+import tech.picnic.errorprone.documentation.BugPatternTestExtractor.TestEntry;
+import tech.picnic.errorprone.documentation.RefasterRuleCollectionTestExtractor.RefasterTestCase;
+import tech.picnic.errorprone.documentation.RefasterRuleCollectionTestExtractor.RefasterTestCases;
+
+/**
+ * A command line utility that produces configuration files for the Jekyll-based Error Prone Support
+ * website.
+ */
+// XXX: Expand the class documentation.
+// XXX: Rename this class. Then also update the reference in `website/.gitignore`.
+// XXX: Now that we have bug checkers in multiple Maven modules, we should
+// likely document the source of each check on the website, perhaps even
+// grouping them by module.
+public final class JekyllCollectionGenerator {
+  // XXX: Find a bette name. Also, externalize this.
+  private static final PathMatcher PATH_MATCHER =
+      FileSystems.getDefault().getPathMatcher("glob:**/target/docs/*.json");
+
+  // XXX: Review class setup.
+  private JekyllCollectionGenerator() {}
+
+  /**
+   * Runs the application.
+   *
+   * @param args Arguments to the application; must specify the path to the Error Prone Support
+   *     project root, and nothing else.
+   * @throws IOException If any file could not be read or written.
+   */
+  public static void main(String[] args) throws IOException {
+    checkArgument(args.length == 1, "Precisely one project root path must be provided");
+    Path projectRoot = Path.of(args[0]).toAbsolutePath();
+
+    generateIndex(projectRoot);
+    PageGenerator.apply(projectRoot);
+  }
+
+  private static void generateIndex(Path projectRoot) throws IOException {
+    try (BufferedWriter writer =
+        Files.newBufferedWriter(projectRoot.resolve("website").resolve("index.md"), UTF_8)) {
+      writer.write("---");
+      writer.newLine();
+      writer.write("layout: default");
+      writer.newLine();
+      writer.write("title: Home");
+      writer.newLine();
+      writer.write("nav_order: 1");
+      writer.newLine();
+      writer.write("---");
+      writer.newLine();
+      writer.write(
+          Files.readString(projectRoot.resolve("README.md")).replace("=\"website/", "=\""));
+    }
+  }
+
+  // XXX: Review this class should be split in two: one for bug patterns and one for Refaster rules.
+  private static final class PageGenerator extends SimpleFileVisitor<Path> {
+    private static final Splitter LINE_SPLITTER = Splitter.on(System.lineSeparator());
+    private static final YAMLMapper YAML_MAPPER =
+        YAMLMapper.builder()
+            .visibility(PropertyAccessor.FIELD, Visibility.ANY)
+            .disable(JsonGenerator.Feature.AUTO_CLOSE_TARGET)
+            .enable(YAMLGenerator.Feature.MINIMIZE_QUOTES)
+            .enable(YAMLGenerator.Feature.USE_PLATFORM_LINE_BREAKS)
+            .build();
+
+    private final List<BugPatternDocumentation> bugPatterns = new ArrayList<>();
+    private final List<BugPatternTestCases> bugPatternTests = new ArrayList<>();
+    private final List<RefasterTestCases> refasterRuleCollectionTests = new ArrayList<>();
+
+    static void apply(Path projectRoot) throws IOException {
+      PageGenerator pageGenerator = new PageGenerator();
+      Files.walkFileTree(projectRoot, pageGenerator);
+      pageGenerator.writePages(projectRoot);
+    }
+
+    @Override
+    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
+      if (!PATH_MATCHER.matches(file)) {
+        return FileVisitResult.CONTINUE;
+      }
+
+      // XXX: If we use a consistent ID separator, then this can become a switch statement. Now we
+      // depend on evaluation order.
+      // XXX: Alternatively, use polymorphism and let Jackson figure it out.
+      // XXX: If we stick with an ID-based approach, then deduplicate the ID references here and in
+      // the `Extractor` implementations.
+      String fileName = file.getFileName().toString();
+      if (fileName.startsWith("bugpattern-test")) {
+        bugPatternTests.add(Json.read(file, BugPatternTestCases.class));
+      } else if (fileName.startsWith("bugpattern")) {
+        bugPatterns.add(Json.read(file, BugPatternDocumentation.class));
+      } else if (fileName.startsWith("refaster-rule-collection-test")) {
+        refasterRuleCollectionTests.add(Json.read(file, RefasterTestCases.class));
+      } else {
+        // XXX: Handle differently?
+        throw new IllegalStateException("Unexpected file: " + fileName);
+      }
+
+      return FileVisitResult.CONTINUE;
+    }
+
+    private void writePages(Path projectRoot) throws IOException {
+      Path website = projectRoot.resolve("website");
+      writePages(
+          website.resolve("_bugpatterns"),
+          getJekyllBugPatternDescriptions(projectRoot),
+          JekyllBugPatternDescription::name);
+      writePages(
+          website.resolve("_refasterrules"),
+          getJekyllRefasterRuleCollectionDescription(),
+          JekyllRefasterRuleCollectionDescription::name);
+    }
+
+    private static <T> void writePages(
+        Path directory, ImmutableList<T> documents, Function<T, String> nameExtractor)
+        throws IOException {
+      for (T document : documents) {
+        Files.createDirectories(directory);
+        try (BufferedWriter writer =
+            Files.newBufferedWriter(
+                directory.resolve(nameExtractor.apply(document) + ".md"), UTF_8)) {
+          YAML_MAPPER.writeValue(writer, document);
+          writer.write("---");
+          writer.newLine();
+        }
+      }
+    }
+
+    private ImmutableList<JekyllBugPatternDescription> getJekyllBugPatternDescriptions(
+        Path projectRoot) {
+      ImmutableListMultimap<String, TestEntry> bugPatternTestCases =
+          bugPatternTests.stream()
+              .flatMap(testCases -> testCases.testCases().stream())
+              .collect(
+                  flatteningToImmutableListMultimap(
+                      BugPatternTestCase::classUnderTest, t -> t.entries().stream()));
+
+      return bugPatterns.stream()
+          .map(
+              b ->
+                  new AutoValue_JekyllCollectionGenerator_JekyllBugPatternDescription(
+                      b.name(),
+                      b.name(),
+                      b.summary(),
+                      b.severityLevel(),
+                      b.tags(),
+                      // XXX: Derive `Path` from filesytem.
+                      Path.of(b.source()).relativize(projectRoot).toString(),
+                      bugPatternTestCases.get(b.fullyQualifiedName()).stream()
+                          .filter(t -> t.type() == TestEntry.TestType.IDENTIFICATION)
+                          .map(t -> ((IdentificationTestEntry) t).code())
+                          .collect(toImmutableList()),
+                      bugPatternTestCases.get(b.fullyQualifiedName()).stream()
+                          .filter(t -> t.type() == TestEntry.TestType.REPLACEMENT)
+                          .map(t -> generateDiff((ReplacementTestEntry) t))
+                          .collect(toImmutableList())))
+          .collect(toImmutableList());
+    }
+
+    private ImmutableList<JekyllRefasterRuleCollectionDescription>
+        getJekyllRefasterRuleCollectionDescription() {
+      ImmutableTable<String, Boolean, List<RefasterTestCase>> refasterTests =
+          refasterRuleCollectionTests.stream()
+              .collect(
+                  toImmutableTable(
+                      RefasterTestCases::ruleCollection,
+                      RefasterTestCases::isInput,
+                      RefasterTestCases::testCases));
+
+      return refasterTests.rowMap().entrySet().stream()
+          .map(
+              c ->
+                  new AutoValue_JekyllCollectionGenerator_JekyllRefasterRuleCollectionDescription(
+                      c.getKey(),
+                      c.getKey(),
+                      // XXX: Derive severity from input.
+                      SUGGESTION,
+                      // XXX: Derive tags from input (or drop this feature).
+                      ImmutableList.of("Simplification"),
+                      // XXX: Derive source location from input.
+                      String.format(
+                          "error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/%s.java",
+                          c.getKey()),
+                      getRules(c.getValue().get(true), c.getValue().get(false))))
+          .collect(toImmutableList());
+    }
+
+    private static ImmutableList<JekyllRefasterRuleCollectionDescription.Rule> getRules(
+        @Nullable List<RefasterTestCase> inputTests, @Nullable List<RefasterTestCase> outputTests) {
+      ImmutableMap<String, String> inputs = indexRefasterTestData(inputTests);
+      ImmutableMap<String, String> outputs = indexRefasterTestData(outputTests);
+
+      return Sets.intersection(inputs.keySet(), outputs.keySet()).stream()
+          .map(
+              name ->
+                  new AutoValue_JekyllCollectionGenerator_JekyllRefasterRuleCollectionDescription_Rule(
+                      name,
+                      // XXX: Derive severity from input.
+                      SUGGESTION,
+                      // XXX: Derive tags from input (or drop this feature).
+                      ImmutableList.of("Simplification"),
+                      generateDiff(
+                          requireNonNull(inputs.get(name), "Input"),
+                          requireNonNull(outputs.get(name), "Output"))))
+          .collect(toImmutableList());
+    }
+
+    private static ImmutableMap<String, String> indexRefasterTestData(
+        @Nullable List<RefasterTestCase> data) {
+      return data == null
+          ? ImmutableMap.of()
+          : data.stream()
+              .collect(toImmutableMap(RefasterTestCase::name, RefasterTestCase::content));
+    }
+
+    private static String generateDiff(ReplacementTestEntry testEntry) {
+      return generateDiff(testEntry.input(), testEntry.output());
+    }
+
+    private static String generateDiff(String before, String after) {
+      // XXX: Extract splitter.
+      List<String> originalLines = LINE_SPLITTER.splitToList(before);
+      List<String> replacementLines = LINE_SPLITTER.splitToList(after);
+
+      Patch<String> diff = DiffUtils.diff(originalLines, replacementLines);
+
+      return UnifiedDiffUtils.generateUnifiedDiff(
+              "", "", originalLines, diff, Integer.MAX_VALUE / 2)
+          .stream()
+          .skip(3)
+          .collect(joining(System.lineSeparator()));
+    }
+  }
+
+  @AutoValue
+  abstract static class JekyllBugPatternDescription {
+    // XXX: Make this a derived property?
+    abstract String title();
+
+    abstract String name();
+
+    abstract String summary();
+
+    abstract SeverityLevel severity();
+
+    abstract ImmutableList<String> tags();
+
+    // XXX: The documentation could link to the original test code. Perhaps even with the correct
+    // line numbers.
+    abstract String source();
+
+    // XXX: The `identification` and `replacement` fields have odd names.
+    abstract ImmutableList<String> identification();
+
+    abstract ImmutableList<String> replacement();
+  }
+
+  @AutoValue
+  abstract static class JekyllRefasterRuleCollectionDescription {
+    // XXX: Make this a derived property?
+    abstract String title();
+
+    abstract String name();
+
+    abstract SeverityLevel severity();
+
+    abstract ImmutableList<String> tags();
+
+    // XXX: The documentation could link to the original test code. Perhaps even with the correct
+    // line numbers. If we do this, we should do the same for individual rules.
+    abstract String source();
+
+    abstract ImmutableList<Rule> rules();
+
+    @AutoValue
+    abstract static class Rule {
+      abstract String name();
+
+      abstract SeverityLevel severity();
+
+      abstract ImmutableList<String> tags();
+
+      abstract String diff();
+    }
+  }
+}

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

@@ -0,0 +1,176 @@
+package tech.picnic.errorprone.documentation;
+
+import static com.google.common.collect.ImmutableList.toImmutableList;
+import static com.google.errorprone.matchers.Matchers.isSubtypeOf;
+import static java.util.stream.Collectors.joining;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.google.auto.service.AutoService;
+import com.google.auto.value.AutoValue;
+import com.google.common.base.Splitter;
+import com.google.common.base.Supplier;
+import com.google.common.base.VerifyException;
+import com.google.common.collect.ImmutableList;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.annotations.FormatMethod;
+import com.google.errorprone.annotations.Immutable;
+import com.google.errorprone.matchers.Matcher;
+import com.sun.source.tree.ClassTree;
+import com.sun.source.tree.MethodTree;
+import java.net.URI;
+import java.util.Optional;
+import java.util.regex.Pattern;
+import tech.picnic.errorprone.documentation.RefasterRuleCollectionTestExtractor.RefasterTestCases;
+import tech.picnic.errorprone.utils.SourceCode;
+
+/**
+ * An {@link Extractor} that describes how to extract data from Refaster rule input and output test
+ * classes.
+ */
+// XXX: Drop this extractor if/when the Refaster test framework is reimplemented such that tests can
+// be located alongside rules, rather than in two additional resource files as currently required by
+// `RefasterRuleCollection`.
+@Immutable
+@AutoService(Extractor.class)
+@SuppressWarnings("rawtypes" /* See https://github.com/google/auto/issues/870. */)
+public final class RefasterRuleCollectionTestExtractor implements Extractor<RefasterTestCases> {
+  private static final Matcher<ClassTree> IS_REFASTER_RULE_COLLECTION_TEST_CASE =
+      isSubtypeOf("tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase");
+  private static final Pattern TEST_CLASS_NAME_PATTERN = Pattern.compile("(.*)Test");
+  private static final Pattern TEST_CLASS_FILE_NAME_PATTERN =
+      Pattern.compile(".*(Input|Output)\\.java");
+  private static final Pattern TEST_METHOD_NAME_PATTERN = Pattern.compile("test(.*)");
+  private static final String LINE_SEPARATOR = "\n";
+  private static final Splitter LINE_SPLITTER = Splitter.on(LINE_SEPARATOR);
+
+  /** Instantiates a new {@link RefasterRuleCollectionTestExtractor} instance. */
+  public RefasterRuleCollectionTestExtractor() {}
+
+  @Override
+  public String identifier() {
+    return "refaster-rule-collection-test";
+  }
+
+  @Override
+  public Optional<RefasterTestCases> tryExtract(ClassTree tree, VisitorState state) {
+    if (!IS_REFASTER_RULE_COLLECTION_TEST_CASE.matches(tree, state)) {
+      return Optional.empty();
+    }
+
+    URI sourceFile = state.getPath().getCompilationUnit().getSourceFile().toUri();
+    return Optional.of(
+        RefasterTestCases.create(
+            sourceFile,
+            getRuleCollectionName(tree),
+            isInputFile(sourceFile),
+            getRefasterTestCases(tree, state)));
+  }
+
+  private static String getRuleCollectionName(ClassTree tree) {
+    String className = tree.getSimpleName().toString();
+
+    // XXX: Instead of throwing an error here, it'd be nicer to have a bug checker validate key
+    // aspects of `RefasterRuleCollectionTestCase` subtypes.
+    return tryExtractPatternGroup(className, TEST_CLASS_NAME_PATTERN)
+        .orElseThrow(
+            violation(
+                "Refaster rule collection test class name '%s' does not match '%s'",
+                className, TEST_CLASS_NAME_PATTERN));
+  }
+
+  private static boolean isInputFile(URI sourceFile) {
+    String path = sourceFile.getPath();
+
+    // XXX: Instead of throwing an error here, it'd be nicer to have a bug checker validate key
+    // aspects of `RefasterRuleCollectionTestCase` subtypes.
+    return "Input"
+        .equals(
+            tryExtractPatternGroup(path, TEST_CLASS_FILE_NAME_PATTERN)
+                .orElseThrow(
+                    violation(
+                        "Refaster rule collection test file name '%s' does not match '%s'",
+                        path, TEST_CLASS_FILE_NAME_PATTERN)));
+  }
+
+  private static ImmutableList<RefasterTestCase> getRefasterTestCases(
+      ClassTree tree, VisitorState state) {
+    return tree.getMembers().stream()
+        .filter(MethodTree.class::isInstance)
+        .map(MethodTree.class::cast)
+        .flatMap(m -> tryExtractRefasterTestCase(m, state).stream())
+        .collect(toImmutableList());
+  }
+
+  private static Optional<RefasterTestCase> tryExtractRefasterTestCase(
+      MethodTree method, VisitorState state) {
+    return tryExtractPatternGroup(method.getName().toString(), TEST_METHOD_NAME_PATTERN)
+        .map(name -> RefasterTestCase.create(name, getFormattedSource(method, state)));
+  }
+
+  /**
+   * Returns the source code for the specified method.
+   *
+   * @implNote This operation attempts to trim leading whitespace, such that the start and end of
+   *     the method declaration are aligned. The implemented heuristic assumes that the code is
+   *     formatted using Google Java Format.
+   */
+  // XXX: Leading Javadoc and other comments are currently not extracted. Consider fixing this.
+  private static String getFormattedSource(MethodTree method, VisitorState state) {
+    String source = SourceCode.treeToString(method, state);
+    int finalNewline = source.lastIndexOf(LINE_SEPARATOR);
+    if (finalNewline < 0) {
+      return source;
+    }
+
+    int indentation = Math.max(0, source.lastIndexOf(' ') - finalNewline);
+    String prefixToStrip = " ".repeat(indentation);
+
+    return LINE_SPLITTER
+        .splitToStream(source)
+        .map(line -> line.startsWith(prefixToStrip) ? line.substring(indentation) : line)
+        .collect(joining(LINE_SEPARATOR));
+  }
+
+  private static Optional<String> tryExtractPatternGroup(String input, Pattern pattern) {
+    java.util.regex.Matcher matcher = pattern.matcher(input);
+    return matcher.matches() ? Optional.of(matcher.group(1)) : Optional.empty();
+  }
+
+  @FormatMethod
+  private static Supplier<VerifyException> violation(String format, Object... args) {
+    return () -> new VerifyException(String.format(format, args));
+  }
+
+  @AutoValue
+  @JsonDeserialize(as = AutoValue_RefasterRuleCollectionTestExtractor_RefasterTestCases.class)
+  abstract static class RefasterTestCases {
+    static RefasterTestCases create(
+        URI source,
+        String ruleCollection,
+        boolean isInput,
+        ImmutableList<RefasterTestCase> testCases) {
+      return new AutoValue_RefasterRuleCollectionTestExtractor_RefasterTestCases(
+          source, ruleCollection, isInput, testCases);
+    }
+
+    abstract URI source();
+
+    abstract String ruleCollection();
+
+    abstract boolean isInput();
+
+    abstract ImmutableList<RefasterTestCase> testCases();
+  }
+
+  @AutoValue
+  @JsonDeserialize(as = AutoValue_RefasterRuleCollectionTestExtractor_RefasterTestCase.class)
+  abstract static class RefasterTestCase {
+    static RefasterTestCase create(String name, String content) {
+      return new AutoValue_RefasterRuleCollectionTestExtractor_RefasterTestCase(name, content);
+    }
+
+    abstract String name();
+
+    abstract String content();
+  }
+}

documentation-support/src/main/java/tech/picnic/errorprone/documentation/models/RefasterTemplateCollectionData.java

@@ -0,0 +1,27 @@
+package tech.picnic.errorprone.documentation.models;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableList;
+
+/**
+ * Object containing all data related to a Refaster template collection. This is solely used for
+ * serialization.
+ */
+// XXX: This class is not yet used.
+@AutoValue
+@JsonDeserialize(as = AutoValue_RefasterTemplateCollectionData.class)
+abstract class RefasterTemplateCollectionData {
+  static RefasterTemplateCollectionData create(
+      String name, String description, String link, ImmutableList<RefasterTemplateData> templates) {
+    return new AutoValue_RefasterTemplateCollectionData(name, description, link, templates);
+  }
+
+  abstract String name();
+
+  abstract String description();
+
+  abstract String link();
+
+  abstract ImmutableList<RefasterTemplateData> templates();
+}

documentation-support/src/main/java/tech/picnic/errorprone/documentation/models/RefasterTemplateData.java

@@ -0,0 +1,23 @@
+package tech.picnic.errorprone.documentation.models;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.google.auto.value.AutoValue;
+import com.google.errorprone.BugPattern.SeverityLevel;
+
+// XXX: This class is not yet used.
+@AutoValue
+@JsonDeserialize(as = AutoValue_RefasterTemplateData.class)
+abstract class RefasterTemplateData {
+  static RefasterTemplateData create(
+      String name, String description, String link, SeverityLevel severityLevel) {
+    return new AutoValue_RefasterTemplateData(name, description, link, severityLevel);
+  }
+
+  abstract String name();
+
+  abstract String description();
+
+  abstract String link();
+
+  abstract SeverityLevel severityLevel();
+}

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

@@ -7,10 +7,10 @@ import java.net.URI;
 import java.nio.file.Path;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
+import tech.picnic.errorprone.documentation.BugPatternTestExtractor.BugPatternTestCase;
+import tech.picnic.errorprone.documentation.BugPatternTestExtractor.BugPatternTestCases;
 import tech.picnic.errorprone.documentation.BugPatternTestExtractor.IdentificationTestEntry;
 import tech.picnic.errorprone.documentation.BugPatternTestExtractor.ReplacementTestEntry;
-import tech.picnic.errorprone.documentation.BugPatternTestExtractor.TestCase;
-import tech.picnic.errorprone.documentation.BugPatternTestExtractor.TestCases;
 
 final class BugPatternTestExtractorTest {
   @Test
@@ -269,11 +269,11 @@ final class BugPatternTestExtractorTest {
     verifyGeneratedFileContent(
         outputDirectory,
         "SingleFileCompilationTestHelperTest",
-        TestCases.create(
+        BugPatternTestCases.create(
             URI.create("file:///SingleFileCompilationTestHelperTest.java"),
             "SingleFileCompilationTestHelperTest",
             ImmutableList.of(
-                TestCase.create(
+                BugPatternTestCase.create(
                     "SingleFileCompilationTestHelperTest.TestChecker",
                     ImmutableList.of(
                         IdentificationTestEntry.create(
@@ -302,11 +302,11 @@ final class BugPatternTestExtractorTest {
     verifyGeneratedFileContent(
         outputDirectory,
         "SingleFileCompilationTestHelperWithSetArgsTest",
-        TestCases.create(
+        BugPatternTestCases.create(
             URI.create("file:///SingleFileCompilationTestHelperWithSetArgsTest.java"),
             "SingleFileCompilationTestHelperWithSetArgsTest",
             ImmutableList.of(
-                TestCase.create(
+                BugPatternTestCase.create(
                     "SingleFileCompilationTestHelperWithSetArgsTest.TestChecker",
                     ImmutableList.of(
                         IdentificationTestEntry.create(
@@ -335,11 +335,11 @@ final class BugPatternTestExtractorTest {
     verifyGeneratedFileContent(
         outputDirectory,
         "MultiFileCompilationTestHelperTest",
-        TestCases.create(
+        BugPatternTestCases.create(
             URI.create("file:///MultiFileCompilationTestHelperTest.java"),
             "MultiFileCompilationTestHelperTest",
             ImmutableList.of(
-                TestCase.create(
+                BugPatternTestCase.create(
                     "MultiFileCompilationTestHelperTest.TestChecker",
                     ImmutableList.of(
                         IdentificationTestEntry.create(
@@ -370,11 +370,11 @@ final class BugPatternTestExtractorTest {
     verifyGeneratedFileContent(
         outputDirectory,
         "SingleFileBugCheckerRefactoringTestHelperTest",
-        TestCases.create(
+        BugPatternTestCases.create(
             URI.create("file:///SingleFileBugCheckerRefactoringTestHelperTest.java"),
             "SingleFileBugCheckerRefactoringTestHelperTest",
             ImmutableList.of(
-                TestCase.create(
+                BugPatternTestCase.create(
                     "SingleFileBugCheckerRefactoringTestHelperTest.TestChecker",
                     ImmutableList.of(
                         ReplacementTestEntry.create(
@@ -408,12 +408,12 @@ final class BugPatternTestExtractorTest {
     verifyGeneratedFileContent(
         outputDirectory,
         "SingleFileBugCheckerRefactoringTestHelperWithSetArgsFixChooserAndCustomTestModeTest",
-        TestCases.create(
+        BugPatternTestCases.create(
             URI.create(
                 "file:///SingleFileBugCheckerRefactoringTestHelperWithSetArgsFixChooserAndCustomTestModeTest.java"),
             "SingleFileBugCheckerRefactoringTestHelperWithSetArgsFixChooserAndCustomTestModeTest",
             ImmutableList.of(
-                TestCase.create(
+                BugPatternTestCase.create(
                     "SingleFileBugCheckerRefactoringTestHelperWithSetArgsFixChooserAndCustomTestModeTest.TestChecker",
                     ImmutableList.of(
                         ReplacementTestEntry.create(
@@ -444,11 +444,11 @@ final class BugPatternTestExtractorTest {
     verifyGeneratedFileContent(
         outputDirectory,
         "MultiFileBugCheckerRefactoringTestHelperTest",
-        TestCases.create(
+        BugPatternTestCases.create(
             URI.create("file:///MultiFileBugCheckerRefactoringTestHelperTest.java"),
             "MultiFileBugCheckerRefactoringTestHelperTest",
             ImmutableList.of(
-                TestCase.create(
+                BugPatternTestCase.create(
                     "MultiFileBugCheckerRefactoringTestHelperTest.TestChecker",
                     ImmutableList.of(
                         ReplacementTestEntry.create(
@@ -484,16 +484,16 @@ final class BugPatternTestExtractorTest {
     verifyGeneratedFileContent(
         outputDirectory,
         "CompilationAndBugCheckerRefactoringTestHelpersTest",
-        TestCases.create(
+        BugPatternTestCases.create(
             URI.create("file:///CompilationAndBugCheckerRefactoringTestHelpersTest.java"),
             "CompilationAndBugCheckerRefactoringTestHelpersTest",
             ImmutableList.of(
-                TestCase.create(
+                BugPatternTestCase.create(
                     "CompilationAndBugCheckerRefactoringTestHelpersTest.TestChecker",
                     ImmutableList.of(
                         IdentificationTestEntry.create(
                             "A.java", "// BUG: Diagnostic contains:\nclass A {}\n"))),
-                TestCase.create(
+                BugPatternTestCase.create(
                     "CompilationAndBugCheckerRefactoringTestHelpersTest.TestChecker",
                     ImmutableList.of(
                         ReplacementTestEntry.create(
@@ -532,17 +532,17 @@ final class BugPatternTestExtractorTest {
     verifyGeneratedFileContent(
         outputDirectory,
         "CompilationAndBugCheckerRefactoringTestHelpersWithCustomCheckerPackageAndNamesTest",
-        TestCases.create(
+        BugPatternTestCases.create(
             URI.create(
                 "file:///CompilationAndBugCheckerRefactoringTestHelpersWithCustomCheckerPackageAndNamesTest.java"),
             "pkg.CompilationAndBugCheckerRefactoringTestHelpersWithCustomCheckerPackageAndNamesTest",
             ImmutableList.of(
-                TestCase.create(
+                BugPatternTestCase.create(
                     "pkg.CompilationAndBugCheckerRefactoringTestHelpersWithCustomCheckerPackageAndNamesTest.CustomTestChecker",
                     ImmutableList.of(
                         IdentificationTestEntry.create(
                             "A.java", "// BUG: Diagnostic contains:\nclass A {}\n"))),
-                TestCase.create(
+                BugPatternTestCase.create(
                     "pkg.CompilationAndBugCheckerRefactoringTestHelpersWithCustomCheckerPackageAndNamesTest.CustomTestChecker2",
                     ImmutableList.of(
                         ReplacementTestEntry.create(
@@ -550,9 +550,9 @@ final class BugPatternTestExtractorTest {
   }
 
   private static void verifyGeneratedFileContent(
-      Path outputDirectory, String testClass, TestCases expected) {
+      Path outputDirectory, String testClass, BugPatternTestCases expected) {
     assertThat(outputDirectory.resolve(String.format("bugpattern-test-%s.json", testClass)))
         .exists()
-        .returns(expected, path -> Json.read(path, TestCases.class));
+        .returns(expected, path -> Json.read(path, BugPatternTestCases.class));
   }
 }

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

@@ -0,0 +1,13 @@
+package tech.picnic.errorprone.documentation;
+
+import java.io.IOException;
+import org.junit.jupiter.api.Test;
+
+// XXX: Implement tests.
+final class JekyllCollectionGeneratorTest {
+  @Test
+  void foo() throws IOException {
+    JekyllCollectionGenerator.main(
+        new String[] {"/home/sschroevers/workspace/picnic/error-prone-support"});
+  }
+}

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

@@ -0,0 +1,166 @@
+package tech.picnic.errorprone.documentation;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import com.google.common.base.VerifyException;
+import com.google.common.collect.ImmutableList;
+import java.net.URI;
+import java.nio.file.Path;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+import tech.picnic.errorprone.documentation.RefasterRuleCollectionTestExtractor.RefasterTestCase;
+import tech.picnic.errorprone.documentation.RefasterRuleCollectionTestExtractor.RefasterTestCases;
+
+final class RefasterRuleCollectionTestExtractorTest {
+  @Test
+  void noRefasterRuleTest(@TempDir Path outputDirectory) {
+    Compilation.compileWithDocumentationGenerator(
+        outputDirectory, "NoRefasterRuleTest.java", "public final class NoRefasterRuleTest {}");
+
+    assertThat(outputDirectory.toAbsolutePath()).isEmptyDirectory();
+  }
+
+  @Test
+  void invalidTestClassName(@TempDir Path outputDirectory) {
+    assertThatThrownBy(
+            () ->
+                Compilation.compileWithDocumentationGenerator(
+                    outputDirectory,
+                    "InvalidTestClassNameInput.java",
+                    "import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;",
+                    "",
+                    "final class InvalidTestClassName implements RefasterRuleCollectionTestCase {}"))
+        .cause()
+        .isInstanceOf(VerifyException.class)
+        .hasMessage(
+            "Refaster rule collection test class name 'InvalidTestClassName' does not match '(.*)Test'");
+  }
+
+  @Test
+  void invalidFileName(@TempDir Path outputDirectory) {
+    assertThatThrownBy(
+            () ->
+                Compilation.compileWithDocumentationGenerator(
+                    outputDirectory,
+                    "InvalidFileNameTest.java",
+                    "import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;",
+                    "",
+                    "final class InvalidFileNameTest implements RefasterRuleCollectionTestCase {}"))
+        .cause()
+        .isInstanceOf(VerifyException.class)
+        .hasMessage(
+            "Refaster rule collection test file name '/InvalidFileNameTest.java' does not match '.*(Input|Output)\\.java'");
+  }
+
+  @Test
+  void emptyRefasterRuleCollectionTestInput(@TempDir Path outputDirectory) {
+    Compilation.compileWithDocumentationGenerator(
+        outputDirectory,
+        "EmptyRefasterRuleCollectionTestInput.java",
+        "import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;",
+        "",
+        "final class EmptyRefasterRuleCollectionTest implements RefasterRuleCollectionTestCase {}");
+
+    verifyGeneratedFileContent(
+        outputDirectory,
+        "EmptyRefasterRuleCollectionTestInput",
+        RefasterTestCases.create(
+            URI.create("file:///EmptyRefasterRuleCollectionTestInput.java"),
+            "EmptyRefasterRuleCollection",
+            /* isInput= */ true,
+            ImmutableList.of()));
+  }
+
+  @Test
+  void singletonRefasterRuleCollectionTestOutput(@TempDir Path outputDirectory) {
+    Compilation.compileWithDocumentationGenerator(
+        outputDirectory,
+        "SingletonRefasterRuleCollectionTestOutput.java",
+        "import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;",
+        "",
+        "final class SingletonRefasterRuleCollectionTest implements RefasterRuleCollectionTestCase {",
+        "  int testMyRule() {",
+        "    return 42;",
+        "  }",
+        "}");
+
+    verifyGeneratedFileContent(
+        outputDirectory,
+        "SingletonRefasterRuleCollectionTestOutput",
+        RefasterTestCases.create(
+            URI.create("file:///SingletonRefasterRuleCollectionTestOutput.java"),
+            "SingletonRefasterRuleCollection",
+            /* isInput= */ false,
+            ImmutableList.of(
+                RefasterTestCase.create(
+                    "MyRule",
+                    """
+                    int testMyRule() {
+                      return 42;
+                    }"""))));
+  }
+
+  @Test
+  void complexRefasterRuleCollectionTestOutput(@TempDir Path outputDirectory) {
+    Compilation.compileWithDocumentationGenerator(
+        outputDirectory,
+        "pkg/ComplexRefasterRuleCollectionTestInput.java",
+        "package pkg;",
+        "",
+        "import com.google.common.collect.ImmutableSet;",
+        "import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;",
+        "",
+        "final class ComplexRefasterRuleCollectionTest implements RefasterRuleCollectionTestCase {",
+        "  private static final String IGNORED_CONSTANT = \"constant\";",
+        "",
+        "  @Override",
+        "  public ImmutableSet<Object> elidedTypesAndStaticImports() {",
+        "    return ImmutableSet.of();",
+        "  }",
+        "",
+        "  /** Javadoc. */",
+        "  String testFirstRule() {",
+        "    return \"Don't panic\";",
+        "  }",
+        "",
+        "  // Comment.",
+        "  String testSecondRule() {",
+        "    return \"Carry a towel\";",
+        "  }",
+        "",
+        "  void testEmptyRule() {}",
+        "}");
+
+    verifyGeneratedFileContent(
+        outputDirectory,
+        "ComplexRefasterRuleCollectionTestInput",
+        RefasterTestCases.create(
+            URI.create("file:///pkg/ComplexRefasterRuleCollectionTestInput.java"),
+            "ComplexRefasterRuleCollection",
+            /* isInput= */ true,
+            ImmutableList.of(
+                RefasterTestCase.create(
+                    "FirstRule",
+                    """
+                    String testFirstRule() {
+                      return "Don't panic";
+                    }"""),
+                RefasterTestCase.create(
+                    "SecondRule",
+                    """
+                    String testSecondRule() {
+                      return "Carry a towel";
+                    }"""),
+                RefasterTestCase.create("EmptyRule", "void testEmptyRule() {}"))));
+  }
+
+  private static void verifyGeneratedFileContent(
+      Path outputDirectory, String testIdentifier, RefasterTestCases expected) {
+    assertThat(
+            outputDirectory.resolve(
+                String.format("refaster-rule-collection-test-%s.json", testIdentifier)))
+        .exists()
+        .returns(expected, path -> Json.read(path, RefasterTestCases.class));
+  }
+}

error-prone-contrib/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.15.1-SNAPSHOT</version>
+        <version>0.18.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>error-prone-contrib</artifactId>
@@ -67,6 +67,11 @@
             <artifactId>jackson-annotations</artifactId>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>com.github.ben-manes.caffeine</groupId>
+            <artifactId>caffeine</artifactId>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>com.google.auto.service</groupId>
             <artifactId>auto-service-annotations</artifactId>
@@ -122,6 +127,11 @@
             <artifactId>jakarta.servlet-api</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>javax.annotation</groupId>
+            <artifactId>javax.annotation-api</artifactId>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>javax.inject</groupId>
             <artifactId>javax.inject</artifactId>
@@ -282,6 +292,55 @@
                             <arg>-Xplugin:DocumentationGenerator -XoutputDirectory=${project.build.directory}/docs</arg>
                         </compilerArgs>
                     </configuration>
+                    <executions>
+                        <!-- The Refaster input/output test classes used by
+                        `RefasterRuleCollection` are modelled as classpath
+                        resources, and thus not subject to the default test
+                        compilation step. These two custom compilation steps
+                        serve two purposes:
+                        - To provide early feedback in case of syntax errors.
+                        - To enable the `DocumentationGenerator` compiler
+                        plugin to extract documentation metadata from them.
+                        Note that the input and output files must be compiled
+                        separately and to distinct output directories, as they
+                        define the same set of class names. -->
+                        <!-- XXX: Drop these executions if/when the Refaster
+                        test framework is reimplemented such that tests can be
+                        located alongside rules, rather than in two additional
+                        resource files. -->
+                        <execution>
+                            <id>compile-refaster-test-input</id>
+                            <goals>
+                                <goal>testCompile</goal>
+                            </goals>
+                            <phase>process-test-resources</phase>
+                            <configuration>
+                                <compileSourceRoots>
+                                    <compileSourceRoot>${project.basedir}/src/test/resources</compileSourceRoot>
+                                </compileSourceRoots>
+                                <testIncludes>
+                                    <testInclude>**/*Input.java</testInclude>
+                                </testIncludes>
+                                <outputDirectory>${project.build.directory}/refaster-test-input</outputDirectory>
+                            </configuration>
+                        </execution>
+                        <execution>
+                            <id>compile-refaster-test-output</id>
+                            <goals>
+                                <goal>testCompile</goal>
+                            </goals>
+                            <phase>process-test-resources</phase>
+                            <configuration>
+                                <compileSourceRoots>
+                                    <compileSourceRoot>${project.basedir}/src/test/resources</compileSourceRoot>
+                                </compileSourceRoots>
+                                <testIncludes>
+                                    <testInclude>**/*Output.java</testInclude>
+                                </testIncludes>
+                                <outputDirectory>${project.build.directory}/refaster-test-output</outputDirectory>
+                            </configuration>
+                        </execution>
+                    </executions>
                 </plugin>
             </plugins>
         </pluginManagement>

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

@@ -0,0 +1,89 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
+import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
+import static com.google.errorprone.BugPattern.StandardTags.LIKELY_ERROR;
+import static com.google.errorprone.matchers.Matchers.anyOf;
+import static com.google.errorprone.matchers.Matchers.instanceMethod;
+import static com.google.errorprone.matchers.Matchers.staticMethod;
+import static com.google.errorprone.matchers.Matchers.typePredicateMatcher;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.MoreTypePredicates.isSubTypeOf;
+import static tech.picnic.errorprone.utils.MoreTypes.generic;
+import static tech.picnic.errorprone.utils.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.google.errorprone.suppliers.Suppliers;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.MemberSelectTree;
+import com.sun.source.tree.MethodInvocationTree;
+import com.sun.tools.javac.code.Type;
+import reactor.core.publisher.Mono;
+
+/**
+ * A {@link BugChecker} that flags {@link Mono#zip} and {@link Mono#zipWith} invocations with a
+ * {@code Mono<Void>} or {@link Mono#empty()} argument or receiver.
+ *
+ * <p>When a zipped reactive stream completes empty, then the other zipped streams will be cancelled
+ * (or not subscribed to), and the operation as a whole will complete empty as well. This is
+ * generally not what was intended.
+ */
+// XXX: Generalize this check to also cover `Flux` zip operations.
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary = "Don't pass a `Mono<Void>` or `Mono.empty()` argument to `Mono#{zip,With}`",
+    link = BUG_PATTERNS_BASE_URL + "EmptyMonoZip",
+    linkType = CUSTOM,
+    severity = ERROR,
+    tags = LIKELY_ERROR)
+public final class EmptyMonoZip extends BugChecker implements MethodInvocationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Supplier<Type> MONO =
+      Suppliers.typeFromString("reactor.core.publisher.Mono");
+  private static final Matcher<ExpressionTree> MONO_ZIP_OR_ZIP_WITH =
+      anyOf(
+          instanceMethod().onDescendantOf(MONO).named("zipWith"),
+          staticMethod().onClass(MONO).named("zip"));
+  private static final Matcher<ExpressionTree> EMPTY_MONO =
+      anyOf(
+          staticMethod().onDescendantOf(MONO).named("empty"),
+          typePredicateMatcher(isSubTypeOf(generic(MONO, type(Void.class.getCanonicalName())))));
+
+  /** Instantiates a new {@link EmptyMonoZip} instance. */
+  public EmptyMonoZip() {}
+
+  @Override
+  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+    if (!MONO_ZIP_OR_ZIP_WITH.matches(tree, state)) {
+      return Description.NO_MATCH;
+    }
+
+    if (hasEmptyReceiver(tree, state)) {
+      return buildDescription(tree)
+          .setMessage("Invoking `Mono#zipWith` on `Mono#empty()` or a `Mono<Void>` is a no-op")
+          .build();
+    }
+
+    if (hasEmptyArguments(tree, state)) {
+      return describeMatch(tree);
+    }
+
+    return Description.NO_MATCH;
+  }
+
+  private static boolean hasEmptyReceiver(MethodInvocationTree tree, VisitorState state) {
+    return tree.getMethodSelect() instanceof MemberSelectTree memberSelect
+        && EMPTY_MONO.matches(memberSelect.getExpression(), state);
+  }
+
+  private static boolean hasEmptyArguments(MethodInvocationTree tree, VisitorState state) {
+    return tree.getArguments().stream().anyMatch(arg -> EMPTY_MONO.matches(arg, state));
+  }
+}

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

@@ -51,6 +51,7 @@ import tech.picnic.errorprone.utils.SourceCode;
 // is effectively the identity operation.
 // XXX: Also flag nullary instance method invocations that represent an identity conversion, such as
 // `Boolean#booleanValue()`, `Byte#byteValue()` and friends.
+// XXX: Also flag redundant round-trip conversions such as `path.toFile().toPath()`.
 @AutoService(BugChecker.class)
 @BugPattern(
     summary = "Avoid or clarify identity conversions",

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

@@ -232,7 +232,7 @@ public final class JUnitValueSource extends BugChecker implements MethodTreeMatc
       @Override
       public @Nullable Void visitReturn(ReturnTree node, @Nullable Void unused) {
         returnExpressions.add(node.getExpression());
-        return super.visitReturn(node, unused);
+        return super.visitReturn(node, null);
       }
 
       @Override

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

@@ -67,14 +67,15 @@ public final class LexicographicalAnnotationAttributeListing extends BugChecker
   private static final long serialVersionUID = 1L;
   private static final ImmutableSet<String> BLACKLISTED_ANNOTATIONS =
       ImmutableSet.of(
-          // XXX: unless JsonPropertyOrder#alphabetic is true...
+          // XXX: Unless `JsonPropertyOrder#alphabetic` is true...
           "com.fasterxml.jackson.annotation.JsonPropertyOrder#value",
           "io.swagger.annotations.ApiImplicitParams#value",
           "io.swagger.v3.oas.annotations.Parameters#value",
           "javax.xml.bind.annotation.XmlType#propOrder",
           "org.springframework.context.annotation.PropertySource#value",
           "org.springframework.test.context.TestPropertySource#locations",
-          "org.springframework.test.context.TestPropertySource#value");
+          "org.springframework.test.context.TestPropertySource#value",
+          "picocli.CommandLine.Option#names");
   private static final String FLAG_PREFIX = "LexicographicalAnnotationAttributeListing:";
   private static final String INCLUDED_ANNOTATIONS_FLAG = FLAG_PREFIX + "Includes";
   private static final String EXCLUDED_ANNOTATIONS_FLAG = FLAG_PREFIX + "Excludes";
@@ -191,7 +192,7 @@ public final class LexicographicalAnnotationAttributeListing extends BugChecker
       @Override
       public @Nullable Void visitIdentifier(IdentifierTree node, @Nullable Void unused) {
         nodes.add(ImmutableList.of(node.getName().toString()));
-        return super.visitIdentifier(node, unused);
+        return super.visitIdentifier(node, null);
       }
 
       @Override
@@ -202,13 +203,13 @@ public final class LexicographicalAnnotationAttributeListing extends BugChecker
                 ? STRING_ARGUMENT_SPLITTER.splitToStream(str).collect(toImmutableList())
                 : ImmutableList.of(String.valueOf(value)));
 
-        return super.visitLiteral(node, unused);
+        return super.visitLiteral(node, null);
       }
 
       @Override
       public @Nullable Void visitPrimitiveType(PrimitiveTypeTree node, @Nullable Void unused) {
         nodes.add(ImmutableList.of(node.getPrimitiveTypeKind().toString()));
-        return super.visitPrimitiveType(node, unused);
+        return super.visitPrimitiveType(node, null);
       }
     }.scan(array, null);
 

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

@@ -210,7 +210,7 @@ public final class NonStaticImport extends BugChecker implements CompilationUnit
           }
         }
 
-        return super.visitIdentifier(node, unused);
+        return super.visitIdentifier(node, null);
       }
     }.scan(tree, null);
   }

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

@@ -0,0 +1,123 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.errorprone.BugPattern.LinkType.NONE;
+import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
+import static com.google.errorprone.BugPattern.StandardTags.PERFORMANCE;
+import static com.google.errorprone.matchers.Matchers.instanceMethod;
+import static com.google.errorprone.matchers.Matchers.staticMethod;
+import static java.util.stream.Collectors.joining;
+
+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.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.refaster.Refaster;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.MemberSelectTree;
+import com.sun.source.tree.MethodInvocationTree;
+import java.util.Optional;
+import java.util.function.Supplier;
+import tech.picnic.errorprone.refaster.matchers.RequiresComputation;
+import tech.picnic.errorprone.utils.SourceCode;
+
+/**
+ * A {@link BugChecker} that flags arguments to {@link Optional#orElse(Object)} that should be
+ * deferred using {@link Optional#orElseGet(Supplier)}.
+ *
+ * <p>The suggested fix assumes that the argument to {@code orElse} does not have side effects. If
+ * it does, the suggested fix changes the program's semantics. Such fragile code must instead be
+ * refactored such that the side-effectful code does not appear accidental.
+ */
+// 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 the `MethodReferenceUsageCheck` bug checker becomes generally usable, consider leaving
+// the method reference cleanup to that check, and express the remainder of the logic in this class
+// using a Refaster template, i.c.w. a `@NotMatches(RequiresComputation.class)` constraint.
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary =
+        """
+        Prefer `Optional#orElseGet` over `Optional#orElse` if the fallback requires additional \
+        computation""",
+    linkType = NONE,
+    severity = WARNING,
+    tags = PERFORMANCE)
+public final class OptionalOrElseGet extends BugChecker implements MethodInvocationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Matcher<ExpressionTree> REQUIRES_COMPUTATION = new RequiresComputation();
+  private static final Matcher<ExpressionTree> OPTIONAL_OR_ELSE_METHOD =
+      instanceMethod().onExactClass(Optional.class.getCanonicalName()).namedAnyOf("orElse");
+  // XXX: Also exclude invocations of `@Placeholder`-annotated methods.
+  private static final Matcher<ExpressionTree> REFASTER_METHOD =
+      staticMethod().onClass(Refaster.class.getCanonicalName());
+
+  /** Instantiates a new {@link OptionalOrElseGet} instance. */
+  public OptionalOrElseGet() {}
+
+  @Override
+  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+    if (!OPTIONAL_OR_ELSE_METHOD.matches(tree, state)) {
+      return Description.NO_MATCH;
+    }
+
+    ExpressionTree argument = Iterables.getOnlyElement(tree.getArguments());
+    if (!REQUIRES_COMPUTATION.matches(argument, state)
+        || REFASTER_METHOD.matches(argument, state)) {
+      return Description.NO_MATCH;
+    }
+
+    /*
+     * We have a match. Construct the method reference or lambda expression to be passed to the
+     * replacement `#orElseGet` invocation.
+     */
+    String newArgument =
+        tryMethodReferenceConversion(argument, state)
+            .orElseGet(() -> "() -> " + SourceCode.treeToString(argument, state));
+
+    /* Construct the suggested fix, replacing the method invocation and its argument. */
+    SuggestedFix fix =
+        SuggestedFix.builder()
+            .merge(SuggestedFixes.renameMethodInvocation(tree, "orElseGet", state))
+            .replace(argument, newArgument)
+            .build();
+
+    return describeMatch(tree, fix);
+  }
+
+  /** Returns the nullary method reference matching the given expression, if any. */
+  private static Optional<String> tryMethodReferenceConversion(
+      ExpressionTree tree, VisitorState state) {
+    if (!(tree instanceof MethodInvocationTree methodInvocation)) {
+      return Optional.empty();
+    }
+
+    if (!methodInvocation.getArguments().isEmpty()) {
+      return Optional.empty();
+    }
+
+    if (!(methodInvocation.getMethodSelect() instanceof MemberSelectTree memberSelect)) {
+      return Optional.empty();
+    }
+
+    if (REQUIRES_COMPUTATION.matches(memberSelect.getExpression(), state)) {
+      return Optional.empty();
+    }
+
+    return Optional.of(
+        SourceCode.treeToString(memberSelect.getExpression(), state)
+            + "::"
+            + (methodInvocation.getTypeArguments().isEmpty()
+                ? ""
+                : methodInvocation.getTypeArguments().stream()
+                    .map(arg -> SourceCode.treeToString(arg, state))
+                    .collect(joining(",", "<", ">")))
+            + memberSelect.getIdentifier());
+  }
+}

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

@@ -39,6 +39,7 @@ import com.google.errorprone.fixes.SuggestedFix;
 import com.google.errorprone.fixes.SuggestedFixes;
 import com.google.errorprone.matchers.Description;
 import com.google.errorprone.matchers.Matchers;
+import com.google.errorprone.predicates.TypePredicates;
 import com.google.errorprone.refaster.ImportPolicy;
 import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.MemberSelectTree;
@@ -101,6 +102,7 @@ public final class StaticImport extends BugChecker implements MemberSelectTreeMa
           Preconditions.class.getCanonicalName(),
           Predicates.class.getCanonicalName(),
           StandardCharsets.class.getCanonicalName(),
+          TypePredicates.class.getCanonicalName(),
           Verify.class.getCanonicalName(),
           "com.fasterxml.jackson.annotation.JsonCreator.Mode",
           "com.fasterxml.jackson.annotation.JsonFormat.Shape",

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

@@ -3,6 +3,7 @@ package tech.picnic.errorprone.refasterrules;
 import com.google.errorprone.refaster.Refaster;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
+import java.util.function.Function;
 import java.util.function.Predicate;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 
@@ -37,7 +38,12 @@ final class ClassRules {
     }
   }
 
-  /** Prefer {@link Class#isInstance(Object)} method references over more verbose alternatives. */
+  /**
+   * Prefer {@link Class#isInstance(Object)} method references over lambda expressions that require
+   * naming a variable.
+   */
+  // XXX: Once the `ClassReferenceIsInstancePredicate` rule is dropped, rename this rule to just
+  // `ClassIsInstancePredicate`.
   static final class ClassLiteralIsInstancePredicate<T, S> {
     @BeforeTemplate
     Predicate<S> before() {
@@ -50,7 +56,11 @@ final class ClassRules {
     }
   }
 
-  /** Prefer {@link Class#isInstance(Object)} method references over more verbose alternatives. */
+  /**
+   * Prefer {@link Class#isInstance(Object)} method references over lambda expressions that require
+   * naming a variable.
+   */
+  // XXX: Drop this rule once the `MethodReferenceUsage` rule is enabled by default.
   static final class ClassReferenceIsInstancePredicate<T, S> {
     @BeforeTemplate
     Predicate<S> before(Class<T> clazz) {
@@ -62,4 +72,39 @@ final class ClassRules {
       return clazz::isInstance;
     }
   }
+
+  /**
+   * Prefer {@link Class#cast(Object)} method references over lambda expressions that require naming
+   * a variable.
+   */
+  // XXX: Once the `ClassReferenceCast` rule is dropped, rename this rule to just `ClassCast`.
+  static final class ClassLiteralCast<T, S> {
+    @BeforeTemplate
+    @SuppressWarnings("unchecked")
+    Function<T, S> before() {
+      return t -> (S) t;
+    }
+
+    @AfterTemplate
+    Function<T, S> after() {
+      return Refaster.<S>clazz()::cast;
+    }
+  }
+
+  /**
+   * Prefer {@link Class#cast(Object)} method references over lambda expressions that require naming
+   * a variable.
+   */
+  // XXX: Drop this rule once the `MethodReferenceUsage` rule is enabled by default.
+  static final class ClassReferenceCast<T, S> {
+    @BeforeTemplate
+    Function<T, S> before(Class<? extends S> clazz) {
+      return o -> clazz.cast(o);
+    }
+
+    @AfterTemplate
+    Function<T, S> after(Class<? extends S> clazz) {
+      return clazz::cast;
+    }
+  }
 }

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

@@ -8,7 +8,9 @@ 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.NotMatches;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
@@ -21,6 +23,7 @@ import java.util.function.Consumer;
 import java.util.function.IntFunction;
 import java.util.stream.Stream;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
+import tech.picnic.errorprone.refaster.matchers.IsRefasterAsVarargs;
 
 /** Refaster rules related to expressions dealing with (arbitrary) collections. */
 // XXX: There are other Guava `Iterables` methods that should not be called if the input is known to
@@ -39,7 +42,7 @@ final class CollectionRules {
       "java:S1155" /* This violation will be rewritten. */,
       "LexicographicalAnnotationAttributeListing" /* `key-*` entry must remain last. */,
       "OptionalFirstCollectionElement" /* This is a more specific template. */,
-      "StreamIsEmpty" /* This is a more specific template. */,
+      "StreamFindAnyIsEmpty" /* This is a more specific template. */,
       "key-to-resolve-AnnotationUseStyle-and-TrailingComment-check-conflict"
     })
     boolean before(Collection<T> collection) {
@@ -184,6 +187,24 @@ final class CollectionRules {
     }
   }
 
+  /** Don't unnecessarily call {@link Stream#distinct()} on an already-unique stream of elements. */
+  // XXX: This rule assumes that the `Set` relies on `Object#equals`, rather than a custom
+  // equivalence relation.
+  // XXX: Expressions that drop or reorder elements from the stream, such as `.filter`, `.skip` and
+  // `sorted`, can similarly be simplified. Covering all cases is better done using an Error Prone
+  // check.
+  static final class SetStream<T> {
+    @BeforeTemplate
+    Stream<?> before(Set<T> set) {
+      return set.stream().distinct();
+    }
+
+    @AfterTemplate
+    Stream<?> after(Set<T> set) {
+      return set.stream();
+    }
+  }
+
   /** Prefer {@link ArrayList#ArrayList(Collection)} over the Guava alternative. */
   @SuppressWarnings(
       "NonApiType" /* Matching against `List` would unnecessarily constrain the rule. */)
@@ -276,6 +297,23 @@ final class CollectionRules {
     }
   }
 
+  /** Prefer {@link Arrays#asList(Object[])} over more contrived alternatives. */
+  // XXX: Consider moving this rule to `ImmutableListRules` and having it suggest
+  // `ImmutableList#copyOf`. That would retain immutability, at the cost of no longer handling
+  // `null`s.
+  static final class ArraysAsList<T> {
+    // XXX: This expression produces an unmodifiable list, while the alternative doesn't.
+    @BeforeTemplate
+    List<T> before(@NotMatches(IsRefasterAsVarargs.class) T[] array) {
+      return Arrays.stream(array).toList();
+    }
+
+    @AfterTemplate
+    List<T> after(T[] array) {
+      return Arrays.asList(array);
+    }
+  }
+
   /** Prefer calling {@link Collection#toArray()} over more contrived alternatives. */
   static final class CollectionToArray<T> {
     @BeforeTemplate

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

@@ -16,13 +16,18 @@ 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.AlsoNegation;
 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.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.Collections;
 import java.util.Comparator;
+import java.util.List;
 import java.util.Optional;
 import java.util.function.BinaryOperator;
 import java.util.function.Function;
@@ -92,6 +97,24 @@ final class ComparatorRules {
     }
   }
 
+  /** Don't explicitly compare enums by their ordinal. */
+  abstract static class ComparingEnum<E extends Enum<E>, T> {
+    @Placeholder(allowsIdentity = true)
+    abstract E toEnumFunction(@MayOptionallyUse T value);
+
+    @BeforeTemplate
+    @SuppressWarnings("EnumOrdinal" /* This violation will be rewritten. */)
+    Comparator<T> before() {
+      return comparingInt(v -> toEnumFunction(v).ordinal());
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    Comparator<T> after() {
+      return comparing(v -> toEnumFunction(v));
+    }
+  }
+
   /** Don't explicitly create {@link Comparator}s unnecessarily. */
   static final class ThenComparing<S, T extends Comparable<? super T>> {
     @BeforeTemplate
@@ -222,18 +245,77 @@ final class ComparatorRules {
     }
   }
 
+  /** Prefer {@link Collections#sort(List)} over more verbose alternatives. */
+  static final class CollectionsSort<T extends Comparable<? super T>> {
+    @BeforeTemplate
+    void before(List<T> collection) {
+      Collections.sort(collection, naturalOrder());
+    }
+
+    @AfterTemplate
+    void after(List<T> collection) {
+      Collections.sort(collection);
+    }
+  }
+
+  /** Prefer {@link Collections#min(Collection)} over more verbose alternatives. */
+  static final class CollectionsMin<T extends Comparable<? super T>> {
+    @BeforeTemplate
+    T before(Collection<T> collection) {
+      return Refaster.anyOf(
+          Collections.min(collection, naturalOrder()), Collections.max(collection, reverseOrder()));
+    }
+
+    @AfterTemplate
+    T after(Collection<T> collection) {
+      return Collections.min(collection);
+    }
+  }
+
   /**
    * Avoid unnecessary creation of a {@link Stream} to determine the minimum of a known collection
    * of values.
    */
-  static final class MinOfVarargs<T> {
+  static final class MinOfArray<S, T extends S> {
     @BeforeTemplate
-    T before(@Repeated T value, Comparator<T> cmp) {
+    T before(T[] array, Comparator<S> cmp) {
+      return Arrays.stream(array).min(cmp).orElseThrow();
+    }
+
+    @AfterTemplate
+    T after(T[] array, Comparator<S> cmp) {
+      return Collections.min(Arrays.asList(array), cmp);
+    }
+  }
+
+  /**
+   * Avoid unnecessary creation of a {@link Stream} to determine the minimum of a known collection
+   * of values.
+   */
+  static final class CollectionsMinWithComparator<S, T extends S> {
+    @BeforeTemplate
+    T before(Collection<T> collection, Comparator<S> cmp) {
+      return collection.stream().min(cmp).orElseThrow();
+    }
+
+    @AfterTemplate
+    T after(Collection<T> collection, Comparator<S> cmp) {
+      return Collections.min(collection, cmp);
+    }
+  }
+
+  /**
+   * Avoid unnecessary creation of a {@link Stream} to determine the minimum of a known collection
+   * of values.
+   */
+  static final class MinOfVarargs<S, T extends S> {
+    @BeforeTemplate
+    T before(@Repeated T value, Comparator<S> cmp) {
       return Stream.of(Refaster.asVarargs(value)).min(cmp).orElseThrow();
     }
 
     @AfterTemplate
-    T after(@Repeated T value, Comparator<T> cmp) {
+    T after(@Repeated T value, Comparator<S> cmp) {
       return Collections.min(Arrays.asList(value), cmp);
     }
   }
@@ -269,7 +351,7 @@ 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) {
+    T before(T value1, T value2, Comparator<? super T> cmp) {
       return Refaster.anyOf(
           cmp.compare(value1, value2) <= 0 ? value1 : value2,
           cmp.compare(value1, value2) > 0 ? value2 : value1,
@@ -284,23 +366,69 @@ final class ComparatorRules {
     }
 
     @AfterTemplate
-    T after(T value1, T value2, Comparator<T> cmp) {
+    T after(T value1, T value2, Comparator<? super T> cmp) {
       return Comparators.min(value1, value2, cmp);
     }
   }
 
+  /** Prefer {@link Collections#max(Collection)} over more verbose alternatives. */
+  static final class CollectionsMax<T extends Comparable<? super T>> {
+    @BeforeTemplate
+    T before(Collection<T> collection) {
+      return Refaster.anyOf(
+          Collections.max(collection, naturalOrder()), Collections.min(collection, reverseOrder()));
+    }
+
+    @AfterTemplate
+    T after(Collection<T> collection) {
+      return Collections.max(collection);
+    }
+  }
+
   /**
    * Avoid unnecessary creation of a {@link Stream} to determine the maximum of a known collection
    * of values.
    */
-  static final class MaxOfVarargs<T> {
+  static final class MaxOfArray<S, T extends S> {
     @BeforeTemplate
-    T before(@Repeated T value, Comparator<T> cmp) {
+    T before(T[] array, Comparator<S> cmp) {
+      return Arrays.stream(array).max(cmp).orElseThrow();
+    }
+
+    @AfterTemplate
+    T after(T[] array, Comparator<S> cmp) {
+      return Collections.max(Arrays.asList(array), cmp);
+    }
+  }
+
+  /**
+   * Avoid unnecessary creation of a {@link Stream} to determine the maximum of a known collection
+   * of values.
+   */
+  static final class CollectionsMaxWithComparator<S, T extends S> {
+    @BeforeTemplate
+    T before(Collection<T> collection, Comparator<S> cmp) {
+      return collection.stream().max(cmp).orElseThrow();
+    }
+
+    @AfterTemplate
+    T after(Collection<T> collection, Comparator<S> cmp) {
+      return Collections.max(collection, cmp);
+    }
+  }
+
+  /**
+   * Avoid unnecessary creation of a {@link Stream} to determine the maximum of a known collection
+   * of values.
+   */
+  static final class MaxOfVarargs<S, T extends S> {
+    @BeforeTemplate
+    T before(@Repeated T value, Comparator<S> cmp) {
       return Stream.of(Refaster.asVarargs(value)).max(cmp).orElseThrow();
     }
 
     @AfterTemplate
-    T after(@Repeated T value, Comparator<T> cmp) {
+    T after(@Repeated T value, Comparator<S> cmp) {
       return Collections.max(Arrays.asList(value), cmp);
     }
   }
@@ -336,7 +464,7 @@ 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) {
+    T before(T value1, T value2, Comparator<? super T> cmp) {
       return Refaster.anyOf(
           cmp.compare(value1, value2) >= 0 ? value1 : value2,
           cmp.compare(value1, value2) < 0 ? value2 : value1,
@@ -351,7 +479,7 @@ final class ComparatorRules {
     }
 
     @AfterTemplate
-    T after(T value1, T value2, Comparator<T> cmp) {
+    T after(T value1, T value2, Comparator<? super T> cmp) {
       return Comparators.max(value1, value2, cmp);
     }
   }
@@ -419,4 +547,34 @@ final class ComparatorRules {
       return maxBy(naturalOrder());
     }
   }
+
+  /** Don't explicitly compare enums by their ordinal. */
+  static final class IsLessThan<E extends Enum<E>> {
+    @BeforeTemplate
+    @SuppressWarnings("EnumOrdinal" /* This violation will be rewritten. */)
+    boolean before(E value1, E value2) {
+      return value1.ordinal() < value2.ordinal();
+    }
+
+    @AfterTemplate
+    @AlsoNegation
+    boolean after(E value1, E value2) {
+      return value1.compareTo(value2) < 0;
+    }
+  }
+
+  /** Don't explicitly compare enums by their ordinal. */
+  static final class IsLessThanOrEqualTo<E extends Enum<E>> {
+    @BeforeTemplate
+    @SuppressWarnings("EnumOrdinal" /* This violation will be rewritten. */)
+    boolean before(E value1, E value2) {
+      return value1.ordinal() <= value2.ordinal();
+    }
+
+    @AfterTemplate
+    @AlsoNegation
+    boolean after(E value1, E value2) {
+      return value1.compareTo(value2) <= 0;
+    }
+  }
 }

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

@@ -1,5 +1,6 @@
 package tech.picnic.errorprone.refasterrules;
 
+import static java.util.function.Predicate.isEqual;
 import static java.util.function.Predicate.not;
 
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
@@ -19,9 +20,9 @@ import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 final class EqualityRules {
   private EqualityRules() {}
 
-  /** Prefer reference-based quality for enums. */
-  // Primitive value comparisons are not listed, because Error Prone flags those out of the box.
-  static final class PrimitiveOrReferenceEquality<T extends Enum<T>> {
+  /** Prefer reference-based equality for enums. */
+  // Primitive value comparisons are not matched, because Error Prone flags those out of the box.
+  static final class EnumReferenceEquality<T extends Enum<T>> {
     /**
      * Enums can be compared by reference. It is safe to do so even in the face of refactorings,
      * because if the type is ever converted to a non-enum, then Error-Prone will complain about any
@@ -30,8 +31,9 @@ final class EqualityRules {
     // XXX: This Refaster rule is the topic of https://github.com/google/error-prone/issues/559. We
     // work around the issue by selecting the "largest replacements". See the `Refaster` check.
     @BeforeTemplate
+    @SuppressWarnings("EnumOrdinal" /* This violation will be rewritten. */)
     boolean before(T a, T b) {
-      return Refaster.anyOf(a.equals(b), Objects.equals(a, b));
+      return Refaster.anyOf(a.equals(b), Objects.equals(a, b), a.ordinal() == b.ordinal());
     }
 
     @AfterTemplate
@@ -42,6 +44,20 @@ final class EqualityRules {
     }
   }
 
+  /** Prefer reference-based equality for enums. */
+  static final class EnumReferenceEqualityLambda<T extends Enum<T>> {
+    @BeforeTemplate
+    Predicate<T> before(T e) {
+      return Refaster.anyOf(isEqual(e), e::equals);
+    }
+
+    @AfterTemplate
+    @SuppressWarnings("java:S1698" /* Reference comparison is valid for enums. */)
+    Predicate<T> after(T e) {
+      return v -> v == e;
+    }
+  }
+
   /** Prefer {@link Object#equals(Object)} over the equivalent lambda function. */
   // 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.

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

@@ -2,12 +2,18 @@ package tech.picnic.errorprone.refasterrules;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
 
+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.Repeated;
+import java.io.File;
 import java.io.IOException;
+import java.net.URI;
 import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.attribute.FileAttribute;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 
 /** Refaster rules related to expressions dealing with files. */
@@ -15,6 +21,49 @@ import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 final class FileRules {
   private FileRules() {}
 
+  /** Prefer the more idiomatic {@link Path#of(URI)} over {@link Paths#get(URI)}. */
+  static final class PathOfUri {
+    @BeforeTemplate
+    Path before(URI uri) {
+      return Paths.get(uri);
+    }
+
+    @AfterTemplate
+    Path after(URI uri) {
+      return Path.of(uri);
+    }
+  }
+
+  /**
+   * Prefer the more idiomatic {@link Path#of(String, String...)} over {@link Paths#get(String,
+   * String...)}.
+   */
+  static final class PathOfString {
+    @BeforeTemplate
+    Path before(String first, @Repeated String more) {
+      return Paths.get(first, more);
+    }
+
+    @AfterTemplate
+    Path after(String first, @Repeated String more) {
+      return Path.of(first, more);
+    }
+  }
+
+  /** Avoid redundant conversions from {@link Path} to {@link File}. */
+  // XXX: Review whether a rule such as this one is better handled by the `IdentityConversion` rule.
+  static final class PathInstance {
+    @BeforeTemplate
+    Path before(Path path) {
+      return path.toFile().toPath();
+    }
+
+    @AfterTemplate
+    Path after(Path path) {
+      return path;
+    }
+  }
+
   /** Prefer {@link Files#readString(Path, Charset)} over more contrived alternatives. */
   static final class FilesReadStringWithCharset {
     @BeforeTemplate
@@ -40,4 +89,44 @@ final class FileRules {
       return Files.readString(path);
     }
   }
+
+  /**
+   * Prefer {@link Files#createTempFile(String, String, FileAttribute[])} over alternatives that
+   * create files with more liberal permissions.
+   */
+  static final class FilesCreateTempFileToFile {
+    @BeforeTemplate
+    @SuppressWarnings({
+      "FilesCreateTempFileInCustomDirectoryToFile" /* This is a more specific template. */,
+      "java:S5443" /* This violation will be rewritten. */,
+      "key-to-resolve-AnnotationUseStyle-and-TrailingComment-check-conflict"
+    })
+    File before(String prefix, String suffix) throws IOException {
+      return Refaster.anyOf(
+          File.createTempFile(prefix, suffix), File.createTempFile(prefix, suffix, null));
+    }
+
+    @AfterTemplate
+    @SuppressWarnings(
+        "java:S5443" /* On POSIX systems the file will only have user read-write permissions. */)
+    File after(String prefix, String suffix) throws IOException {
+      return Files.createTempFile(prefix, suffix).toFile();
+    }
+  }
+
+  /**
+   * Prefer {@link Files#createTempFile(Path, String, String, FileAttribute[])} over alternatives
+   * that create files with more liberal permissions.
+   */
+  static final class FilesCreateTempFileInCustomDirectoryToFile {
+    @BeforeTemplate
+    File before(File directory, String prefix, String suffix) throws IOException {
+      return File.createTempFile(prefix, suffix, directory);
+    }
+
+    @AfterTemplate
+    File after(File directory, String prefix, String suffix) throws IOException {
+      return Files.createTempFile(directory.toPath(), prefix, suffix).toFile();
+    }
+  }
 }

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

@@ -302,16 +302,22 @@ import tech.picnic.errorprone.refaster.annotation.TypeMigration;
 final class JUnitToAssertJRules {
   private JUnitToAssertJRules() {}
 
-  static final class ThrowNewAssertionError {
+  static final class Fail<T> {
     @BeforeTemplate
-    void before() {
-      Assertions.fail();
+    T before() {
+      return Assertions.fail();
     }
 
+    // XXX: Add `@UseImportPolicy(STATIC_IMPORT_ALWAYS)` once
+    // https://github.com/google/error-prone/pull/3584 is resolved. Until that time, statically
+    // importing AssertJ's `fail` is likely to clash with an existing static import of JUnit's
+    // `fail`. Note that combining Error Prone's `RemoveUnusedImports` and
+    // `UnnecessarilyFullyQualified` checks and our `StaticImport` check will anyway cause the
+    // method to be imported statically if possible; just in a less efficient manner.
     @AfterTemplate
     @DoNotCall
-    void after() {
-      throw new AssertionError();
+    T after() {
+      return fail();
     }
   }
 
@@ -321,12 +327,7 @@ final class JUnitToAssertJRules {
       return Assertions.fail(message);
     }
 
-    // XXX: Add `@UseImportPolicy(STATIC_IMPORT_ALWAYS)` once
-    // https://github.com/google/error-prone/pull/3584 is resolved. Until that time, statically
-    // importing AssertJ's `fail` is likely to clash with an existing static import of JUnit's
-    // `fail`. Note that combining Error Prone's `RemoveUnusedImports` and
-    // `UnnecessarilyFullyQualified` checks and our `StaticImport` check will anyway cause the
-    // method to be imported statically if possible; just in a less efficient manner.
+    // XXX: Add `@UseImportPolicy(STATIC_IMPORT_ALWAYS)`. See `Fail` comment.
     @AfterTemplate
     T after(String message) {
       return fail(message);
@@ -339,28 +340,24 @@ final class JUnitToAssertJRules {
       return Assertions.fail(message, throwable);
     }
 
-    // XXX: Add `@UseImportPolicy(STATIC_IMPORT_ALWAYS)` once
-    // https://github.com/google/error-prone/pull/3584 is resolved. Until that time, statically
-    // importing AssertJ's `fail` is likely to clash with an existing static import of JUnit's
-    // `fail`. Note that combining Error Prone's `RemoveUnusedImports` and
-    // `UnnecessarilyFullyQualified` checks and our `StaticImport` check will anyway cause the
-    // method to be imported statically if possible; just in a less efficient manner.
+    // XXX: Add `@UseImportPolicy(STATIC_IMPORT_ALWAYS)`. See `Fail` comment.
     @AfterTemplate
     T after(String message, Throwable throwable) {
       return fail(message, throwable);
     }
   }
 
-  static final class FailWithThrowable {
+  static final class FailWithThrowable<T> {
     @BeforeTemplate
-    void before(Throwable throwable) {
-      Assertions.fail(throwable);
+    T before(Throwable throwable) {
+      return Assertions.fail(throwable);
     }
 
+    // XXX: Add `@UseImportPolicy(STATIC_IMPORT_ALWAYS)`. See `Fail` comment.
     @AfterTemplate
     @DoNotCall
-    void after(Throwable throwable) {
-      throw new AssertionError(throwable);
+    T after(Throwable throwable) {
+      return fail(throwable);
     }
   }
 

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

@@ -20,13 +20,26 @@ 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;
+import tech.picnic.errorprone.refaster.matchers.RequiresComputation;
 
 /** Refaster rules related to expressions dealing with {@link Optional}s. */
 @OnlineDocumentation
 final class OptionalRules {
   private OptionalRules() {}
 
+  /** Prefer {@link Optional#empty()} over the more contrived alternative. */
+  static final class OptionalEmpty<T> {
+    @BeforeTemplate
+    Optional<T> before() {
+      return Optional.ofNullable(null);
+    }
+
+    @AfterTemplate
+    Optional<T> after() {
+      return Optional.empty();
+    }
+  }
+
   static final class OptionalOfNullable<T> {
     // XXX: Refaster should be smart enough to also rewrite occurrences in which there are
     // parentheses around the null check, but that's currently not the case. Try to fix that.
@@ -242,24 +255,21 @@ 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.
+   * Prefer {@link Optional#orElse(Object)} over {@link Optional#orElseGet(Supplier)} if the
+   * fallback value does not require non-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> {
+  // XXX: This rule is the counterpart to the `OptionalOrElseGet` bug checker. Once the
+  // `MethodReferenceUsage` bug checker is "production ready", that bug checker may similarly be
+  // replaced with a Refaster rule.
+  static final class OptionalOrElse<T> {
     @BeforeTemplate
-    T before(Optional<T> optional, @NotMatches(IsLikelyTrivialComputation.class) T value) {
-      return optional.orElse(value);
+    T before(Optional<T> optional, @NotMatches(RequiresComputation.class) T value) {
+      return optional.orElseGet(() -> value);
     }
 
     @AfterTemplate
     T after(Optional<T> optional, T value) {
-      return optional.orElseGet(() -> value);
+      return optional.orElse(value);
     }
   }
 
@@ -360,7 +370,12 @@ final class OptionalRules {
   /** Prefer {@link Optional#or(Supplier)} over more verbose alternatives. */
   static final class OptionalOrOtherOptional<T> {
     @BeforeTemplate
-    @SuppressWarnings("NestedOptionals" /* Auto-fix for the `NestedOptionals` check. */)
+    @SuppressWarnings({
+      "LexicographicalAnnotationAttributeListing" /* `key-*` entry must remain last. */,
+      "NestedOptionals" /* This violation will be rewritten. */,
+      "OptionalOrElse" /* Parameters represent expressions that may require computation. */,
+      "key-to-resolve-AnnotationUseStyle-and-TrailingComment-check-conflict"
+    })
     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.
@@ -386,9 +401,13 @@ final class OptionalRules {
    */
   static final class OptionalIdentity<T> {
     @BeforeTemplate
+    @SuppressWarnings("NestedOptionals")
     Optional<T> before(Optional<T> optional, Comparator<? super T> comparator) {
       return Refaster.anyOf(
           optional.or(Refaster.anyOf(() -> Optional.empty(), Optional::empty)),
+          optional
+              .map(Optional::of)
+              .orElseGet(Refaster.anyOf(() -> Optional.empty(), Optional::empty)),
           optional.stream().findFirst(),
           optional.stream().findAny(),
           optional.stream().min(comparator),
@@ -442,9 +461,7 @@ final class OptionalRules {
   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));
+      return optional.map(Stream::of).orElseGet(Stream::empty);
     }
 
     @AfterTemplate

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

@@ -8,6 +8,8 @@ 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.common.primitives.UnsignedInts;
+import com.google.common.primitives.UnsignedLongs;
 import com.google.errorprone.refaster.Refaster;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.AlsoNegation;
@@ -76,6 +78,8 @@ final class PrimitiveRules {
   }
 
   /** Prefer {@link Math#toIntExact(long)} over the Guava alternative. */
+  // XXX: This rule changes the exception possibly thrown from `IllegalArgumentException` to
+  // `ArithmeticException`.
   static final class LongToIntExact {
     @BeforeTemplate
     int before(long l) {
@@ -192,72 +196,8 @@ final class PrimitiveRules {
     }
   }
 
-  /** 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. */
+  // XXX: Drop this rule once https://github.com/google/guava/pull/7371 is released.
   static final class FloatCompare {
     @BeforeTemplate
     int before(float a, float b) {
@@ -271,6 +211,7 @@ final class PrimitiveRules {
   }
 
   /** Prefer {@link Double#compare(double, double)} over the Guava alternative. */
+  // XXX: Drop this rule once https://github.com/google/guava/pull/7371 is released.
   static final class DoubleCompare {
     @BeforeTemplate
     int before(double a, double b) {
@@ -442,4 +383,205 @@ final class PrimitiveRules {
       return Long.signum(l) == -1;
     }
   }
+
+  /** Prefer JDK's {@link Integer#compareUnsigned(int, int)} over third-party alternatives. */
+  static final class IntegerCompareUnsigned {
+    @BeforeTemplate
+    int before(int x, int y) {
+      return UnsignedInts.compare(x, y);
+    }
+
+    @AfterTemplate
+    int after(int x, int y) {
+      return Integer.compareUnsigned(x, y);
+    }
+  }
+
+  /** Prefer JDK's {@link Long#compareUnsigned(long, long)} over third-party alternatives. */
+  static final class LongCompareUnsigned {
+    @BeforeTemplate
+    long before(long x, long y) {
+      return UnsignedLongs.compare(x, y);
+    }
+
+    @AfterTemplate
+    long after(long x, long y) {
+      return Long.compareUnsigned(x, y);
+    }
+  }
+
+  /** Prefer JDK's {@link Integer#divideUnsigned(int, int)} over third-party alternatives. */
+  static final class IntegerDivideUnsigned {
+    @BeforeTemplate
+    int before(int x, int y) {
+      return UnsignedInts.divide(x, y);
+    }
+
+    @AfterTemplate
+    int after(int x, int y) {
+      return Integer.divideUnsigned(x, y);
+    }
+  }
+
+  /** Prefer JDK's {@link Long#divideUnsigned(long, long)} over third-party alternatives. */
+  static final class LongDivideUnsigned {
+    @BeforeTemplate
+    long before(long x, long y) {
+      return UnsignedLongs.divide(x, y);
+    }
+
+    @AfterTemplate
+    long after(long x, long y) {
+      return Long.divideUnsigned(x, y);
+    }
+  }
+
+  /** Prefer JDK's {@link Integer#remainderUnsigned(int, int)} over third-party alternatives. */
+  static final class IntegerRemainderUnsigned {
+    @BeforeTemplate
+    int before(int x, int y) {
+      return UnsignedInts.remainder(x, y);
+    }
+
+    @AfterTemplate
+    int after(int x, int y) {
+      return Integer.remainderUnsigned(x, y);
+    }
+  }
+
+  /** Prefer JDK's {@link Long#remainderUnsigned(long, long)} over third-party alternatives. */
+  static final class LongRemainderUnsigned {
+    @BeforeTemplate
+    long before(long x, long y) {
+      return UnsignedLongs.remainder(x, y);
+    }
+
+    @AfterTemplate
+    long after(long x, long y) {
+      return Long.remainderUnsigned(x, y);
+    }
+  }
+
+  /**
+   * Prefer JDK's {@link Integer#parseUnsignedInt(String)} over third-party or more verbose
+   * alternatives.
+   */
+  static final class IntegerParseUnsignedInt {
+    @BeforeTemplate
+    int before(String string) {
+      return Refaster.anyOf(
+          UnsignedInts.parseUnsignedInt(string), Integer.parseUnsignedInt(string, 10));
+    }
+
+    @AfterTemplate
+    int after(String string) {
+      return Integer.parseUnsignedInt(string);
+    }
+  }
+
+  /**
+   * Prefer JDK's {@link Long#parseUnsignedLong(String)} over third-party or more verbose
+   * alternatives.
+   */
+  static final class LongParseUnsignedLong {
+    @BeforeTemplate
+    long before(String string) {
+      return Refaster.anyOf(
+          UnsignedLongs.parseUnsignedLong(string), Long.parseUnsignedLong(string, 10));
+    }
+
+    @AfterTemplate
+    long after(String string) {
+      return Long.parseUnsignedLong(string);
+    }
+  }
+
+  /** Prefer JDK's {@link Integer#parseUnsignedInt(String, int)} over third-party alternatives. */
+  static final class IntegerParseUnsignedIntWithRadix {
+    @BeforeTemplate
+    int before(String string, int radix) {
+      return UnsignedInts.parseUnsignedInt(string, radix);
+    }
+
+    @AfterTemplate
+    int after(String string, int radix) {
+      return Integer.parseUnsignedInt(string, radix);
+    }
+  }
+
+  /** Prefer JDK's {@link Long#parseUnsignedLong(String, int)} over third-party alternatives. */
+  static final class LongParseUnsignedLongWithRadix {
+    @BeforeTemplate
+    long before(String string, int radix) {
+      return UnsignedLongs.parseUnsignedLong(string, radix);
+    }
+
+    @AfterTemplate
+    long after(String string, int radix) {
+      return Long.parseUnsignedLong(string, radix);
+    }
+  }
+
+  /**
+   * Prefer JDK's {@link Integer#toUnsignedString(int)} over third-party or more verbose
+   * alternatives.
+   */
+  static final class IntegerToUnsignedString {
+    @BeforeTemplate
+    String before(int i) {
+      return Refaster.anyOf(UnsignedInts.toString(i), Integer.toUnsignedString(i, 10));
+    }
+
+    @AfterTemplate
+    String after(int i) {
+      return Integer.toUnsignedString(i);
+    }
+  }
+
+  /**
+   * Prefer JDK's {@link Long#toUnsignedString(long)} over third-party or more verbose alternatives.
+   */
+  static final class LongToUnsignedString {
+    @BeforeTemplate
+    String before(long i) {
+      return Refaster.anyOf(UnsignedLongs.toString(i), Long.toUnsignedString(i, 10));
+    }
+
+    @AfterTemplate
+    String after(long i) {
+      return Long.toUnsignedString(i);
+    }
+  }
+
+  /**
+   * Prefer JDK's {@link Integer#toUnsignedString(int,int)} over third-party or more verbose
+   * alternatives.
+   */
+  static final class IntegerToUnsignedStringWithRadix {
+    @BeforeTemplate
+    String before(int i, int radix) {
+      return UnsignedInts.toString(i, radix);
+    }
+
+    @AfterTemplate
+    String after(int i, int radix) {
+      return Integer.toUnsignedString(i, radix);
+    }
+  }
+
+  /**
+   * Prefer JDK's {@link Long#toUnsignedString(long,int)} over third-party or more verbose
+   * alternatives.
+   */
+  static final class LongToUnsignedStringWithRadix {
+    @BeforeTemplate
+    String before(long i, int radix) {
+      return UnsignedLongs.toString(i, radix);
+    }
+
+    @AfterTemplate
+    String after(long i, int radix) {
+      return Long.toUnsignedString(i, radix);
+    }
+  }
 }

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

@@ -3,7 +3,6 @@ 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.Comparator.naturalOrder;
 import static java.util.Comparator.reverseOrder;
@@ -14,6 +13,7 @@ import static java.util.stream.Collectors.toCollection;
 import static org.assertj.core.api.Assertions.assertThat;
 import static reactor.function.TupleUtils.function;
 
+import com.github.benmanes.caffeine.cache.AsyncLoadingCache;
 import com.google.common.collect.ImmutableCollection;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
@@ -34,6 +34,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.Callable;
+import java.util.concurrent.CompletableFuture;
 import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
 import java.util.function.Consumer;
@@ -41,6 +42,7 @@ import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
 import java.util.stream.Collector;
+import java.util.stream.Stream;
 import org.jspecify.annotations.Nullable;
 import org.reactivestreams.Publisher;
 import reactor.core.publisher.Flux;
@@ -52,7 +54,6 @@ import reactor.util.context.Context;
 import reactor.util.function.Tuple2;
 import tech.picnic.errorprone.refaster.annotation.Description;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
-import tech.picnic.errorprone.refaster.annotation.Severity;
 import tech.picnic.errorprone.refaster.matchers.IsEmpty;
 import tech.picnic.errorprone.refaster.matchers.IsIdentityOperation;
 import tech.picnic.errorprone.refaster.matchers.ThrowsCheckedException;
@@ -380,30 +381,23 @@ final class ReactorRules {
   }
 
   /**
-   * Prefer {@link Flux#take(long, boolean)} over {@link Flux#take(long)}.
+   * Prefer {@link Flux#take(long)} over {@link Flux#take(long, boolean)} where relevant.
    *
    * <p>In Reactor versions prior to 3.5.0, {@code Flux#take(long)} makes an unbounded request
-   * upstream, and is equivalent to {@code Flux#take(long, false)}. In 3.5.0, the behavior of {@code
-   * Flux#take(long)} will change to that of {@code Flux#take(long, true)}.
-   *
-   * <p>The intent with this Refaster rule is to get the new behavior before upgrading to Reactor
-   * 3.5.0.
+   * upstream, and is equivalent to {@code Flux#take(long, false)}. From version 3.5.0 onwards, the
+   * behavior of {@code Flux#take(long)} instead matches {@code Flux#take(long, true)}.
    */
-  // XXX: Drop this rule some time after upgrading to Reactor 3.6.0, or introduce a way to apply
-  // this rule only when an older version of Reactor is on the classpath.
-  // XXX: Once Reactor 3.6.0 is out, introduce a rule that rewrites code in the opposite direction.
   @Description(
-      "Prior to Reactor 3.5.0, `take(n)` requests and unbounded number of elements upstream.")
-  @Severity(WARNING)
+      "From Reactor 3.5.0 onwards, `take(n)` no longer requests an unbounded number of elements upstream.")
   static final class FluxTake<T> {
     @BeforeTemplate
     Flux<T> before(Flux<T> flux, long n) {
-      return flux.take(n);
+      return flux.take(n, /* limitRequest= */ true);
     }
 
     @AfterTemplate
     Flux<T> after(Flux<T> flux, long n) {
-      return flux.take(n, /* limitRequest= */ true);
+      return flux.take(n);
     }
   }
 
@@ -489,15 +483,20 @@ final class ReactorRules {
   }
 
   /** Prefer {@link Flux#just(Object)} over more contrived alternatives. */
-  static final class FluxJust {
+  static final class FluxJust<T> {
     @BeforeTemplate
-    Flux<Integer> before(int start) {
-      return Flux.range(start, 1);
+    Flux<Integer> before(int value) {
+      return Flux.range(value, 1);
+    }
+
+    @BeforeTemplate
+    Flux<T> before(T value) {
+      return Mono.just(value).repeat().take(1);
     }
 
     @AfterTemplate
-    Flux<Integer> after(int start) {
-      return Flux.just(start);
+    Flux<T> after(T value) {
+      return Flux.just(value);
     }
   }
 
@@ -566,6 +565,7 @@ final class ReactorRules {
         @Matches(IsIdentityOperation.class)
             Function<? super P, ? extends Publisher<? extends S>> identityOperation) {
       return Refaster.anyOf(
+          flux.concatMap(function, 0),
           flux.flatMap(function, 1),
           flux.flatMapSequential(function, 1),
           flux.map(function).concatMap(identityOperation));
@@ -1205,6 +1205,26 @@ final class ReactorRules {
     }
   }
 
+  /** Prefer {@link Flux#fromIterable(Iterable)} over less efficient alternatives. */
+  // XXX: Once the `FluxFromStreamSupplier` rule is constrained using
+  // `@NotMatches(IsIdentityOperation.class)`, this rule should also cover
+  // `Flux.fromStream(collection.stream())`.
+  static final class FluxFromIterable<T> {
+    // XXX: Once the `MethodReferenceUsage` check is generally enabled, drop the second
+    // `Refaster.anyOf` variant.
+    @BeforeTemplate
+    Flux<T> before(Collection<T> collection) {
+      return Flux.fromStream(
+          Refaster.<Supplier<Stream<? extends T>>>anyOf(
+              collection::stream, () -> collection.stream()));
+    }
+
+    @AfterTemplate
+    Flux<T> after(Collection<T> collection) {
+      return Flux.fromIterable(collection);
+    }
+  }
+
   /**
    * Prefer {@link Flux#count()} followed by a conversion from {@code long} to {@code int} over
    * collecting into a list and counting its elements.
@@ -1899,4 +1919,76 @@ final class ReactorRules {
       return step.verifyTimeout(duration);
     }
   }
+
+  /**
+   * Prefer {@link Mono#fromFuture(Supplier)} over {@link Mono#fromFuture(CompletableFuture)}, as
+   * the former may defer initiation of the asynchronous computation until subscription.
+   */
+  static final class MonoFromFutureSupplier<T> {
+    // XXX: Constrain the `future` parameter using `@NotMatches(IsIdentityOperation.class)` once
+    // `IsIdentityOperation` no longer matches nullary method invocations.
+    @BeforeTemplate
+    Mono<T> before(CompletableFuture<T> future) {
+      return Mono.fromFuture(future);
+    }
+
+    @AfterTemplate
+    Mono<T> after(CompletableFuture<T> future) {
+      return Mono.fromFuture(() -> future);
+    }
+  }
+
+  /**
+   * Prefer {@link Mono#fromFuture(Supplier, boolean)} over {@link
+   * Mono#fromFuture(CompletableFuture, boolean)}, as the former may defer initiation of the
+   * asynchronous computation until subscription.
+   */
+  static final class MonoFromFutureSupplierBoolean<T> {
+    // XXX: Constrain the `future` parameter using `@NotMatches(IsIdentityOperation.class)` once
+    // `IsIdentityOperation` no longer matches nullary method invocations.
+    @BeforeTemplate
+    Mono<T> before(CompletableFuture<T> future, boolean suppressCancel) {
+      return Mono.fromFuture(future, suppressCancel);
+    }
+
+    @AfterTemplate
+    Mono<T> after(CompletableFuture<T> future, boolean suppressCancel) {
+      return Mono.fromFuture(() -> future, suppressCancel);
+    }
+  }
+
+  /**
+   * Don't propagate {@link Mono} cancellations to an upstream cache value computation, as
+   * completion of such computations may benefit concurrent or subsequent cache usages.
+   */
+  static final class MonoFromFutureAsyncLoadingCacheGet<K, V> {
+    @BeforeTemplate
+    Mono<V> before(AsyncLoadingCache<K, V> cache, K key) {
+      return Mono.fromFuture(() -> cache.get(key));
+    }
+
+    @AfterTemplate
+    Mono<V> after(AsyncLoadingCache<K, V> cache, K key) {
+      return Mono.fromFuture(() -> cache.get(key), /* suppressCancel= */ true);
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#fromStream(Supplier)} over {@link Flux#fromStream(Stream)}, as the former
+   * yields a {@link Flux} that is more likely to behave as expected when subscribed to more than
+   * once.
+   */
+  static final class FluxFromStreamSupplier<T> {
+    // XXX: Constrain the `stream` parameter using `@NotMatches(IsIdentityOperation.class)` once
+    // `IsIdentityOperation` no longer matches nullary method invocations.
+    @BeforeTemplate
+    Flux<T> before(Stream<T> stream) {
+      return Flux.fromStream(stream);
+    }
+
+    @AfterTemplate
+    Flux<T> after(Stream<T> stream) {
+      return Flux.fromStream(() -> stream);
+    }
+  }
 }

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

@@ -25,6 +25,7 @@ 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.AlsoNegation;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
 import com.google.errorprone.refaster.annotation.Matches;
 import com.google.errorprone.refaster.annotation.MayOptionallyUse;
@@ -256,7 +257,7 @@ final class StreamRules {
   // 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, K, V, C extends Collection<K>, M extends Map<K, V>> {
+  static final class StreamFindAnyIsEmpty<T, K, V, C extends Collection<K>, M extends Map<K, V>> {
     @BeforeTemplate
     boolean before(Stream<T> stream, Collector<? super T, ?, ? extends C> collector) {
       return Refaster.anyOf(
@@ -274,20 +275,20 @@ final class StreamRules {
     }
 
     @AfterTemplate
+    @AlsoNegation
     boolean after(Stream<T> stream) {
       return stream.findAny().isEmpty();
     }
   }
 
-  /** In order to test whether a stream has any element, simply try to find one. */
-  static final class StreamIsNotEmpty<T> {
+  /**
+   * Prefer {@link Stream#findAny()} over {@link Stream#findFirst()} if one only cares whether the
+   * stream is nonempty.
+   */
+  static final class StreamFindAnyIsPresent<T> {
     @BeforeTemplate
     boolean before(Stream<T> stream) {
-      return Refaster.anyOf(
-          stream.count() != 0,
-          stream.count() > 0,
-          stream.count() >= 1,
-          stream.findFirst().isPresent());
+      return stream.findFirst().isPresent();
     }
 
     @AfterTemplate

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

@@ -161,8 +161,9 @@ final class TestNGToAssertJRules {
 
     @AfterTemplate
     @DoNotCall
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     void after() {
-      throw new AssertionError();
+      fail();
     }
   }
 

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

@@ -0,0 +1,80 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+
+final class EmptyMonoZipTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(EmptyMonoZip.class, getClass())
+        .expectErrorMessage(
+            "ARGUMENT",
+            m ->
+                m.contains(
+                    "Don't pass a `Mono<Void>` or `Mono.empty()` argument to `Mono#{zip,With}`"))
+        .expectErrorMessage(
+            "RECEIVER",
+            m ->
+                m.contains(
+                    "Invoking `Mono#zipWith` on `Mono#empty()` or a `Mono<Void>` is a no-op"))
+        .addSourceLines(
+            "A.java",
+            "import static reactor.core.publisher.Mono.zip;",
+            "",
+            "import reactor.core.publisher.Flux;",
+            "import reactor.core.publisher.Mono;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Flux.just(1).zip(Mono.empty(), Flux.just(2));",
+            "",
+            "    Mono<Void> voidMono = Mono.empty();",
+            "    Mono<Integer> integerMono = Mono.empty();",
+            "",
+            "    zip(Mono.just(1), Mono.just(2));",
+            "    Mono.zip(Mono.just(1), Mono.just(2));",
+            "    Mono.zip(Mono.just(1), Mono.just(2), Mono.just(3));",
+            "    Mono.zip(integerMono, integerMono);",
+            "",
+            "    // BUG: Diagnostic matches: ARGUMENT",
+            "    zip(Mono.empty(), Mono.empty());",
+            "    // BUG: Diagnostic matches: ARGUMENT",
+            "    Mono.zip(Mono.empty(), Mono.empty());",
+            "    // BUG: Diagnostic matches: ARGUMENT",
+            "    Mono.zip(voidMono, Mono.just(1));",
+            "    // BUG: Diagnostic matches: ARGUMENT",
+            "    Mono.zip(voidMono, voidMono);",
+            "    // BUG: Diagnostic matches: ARGUMENT",
+            "    Mono.zip(Mono.just(1).then(), Mono.just(2));",
+            "    // BUG: Diagnostic matches: ARGUMENT",
+            "    Mono.zip(Mono.just(1), Mono.just(2), voidMono);",
+            "",
+            "    Mono.just(1).zipWith(Mono.just(2));",
+            "    Mono.just(1).zipWith(integerMono);",
+            "    Mono.just(1).zipWith(integerMono, (a, b) -> a + b);",
+            "",
+            "    // BUG: Diagnostic matches: ARGUMENT",
+            "    Mono.just(1).zipWith(Mono.empty());",
+            "    // BUG: Diagnostic matches: ARGUMENT",
+            "    Mono.just(1).zipWith(voidMono);",
+            "    // BUG: Diagnostic matches: RECEIVER",
+            "    Mono.empty().zipWith(Mono.just(1));",
+            "    // BUG: Diagnostic matches: RECEIVER",
+            "    voidMono.zipWith(Mono.just(1));",
+            "  }",
+            "",
+            "  abstract class MyMono extends Mono<Object> {",
+            "    void m() {",
+            "      zip(Mono.just(1), Mono.just(2));",
+            "      // BUG: Diagnostic matches: ARGUMENT",
+            "      zip(Mono.empty(), Mono.empty());",
+            "",
+            "      zipWith(Mono.just(1));",
+            "      // BUG: Diagnostic matches: ARGUMENT",
+            "      zipWith(Mono.empty());",
+            "    }",
+            "  }",
+            "}")
+        .doTest();
+  }
+}

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

@@ -0,0 +1,137 @@
+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 OptionalOrElseGetTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(OptionalOrElseGet.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import com.google.errorprone.refaster.Refaster;",
+            "import java.util.Optional;",
+            "import java.util.function.Supplier;",
+            "",
+            "class A {",
+            "  private final Optional<Object> optional = Optional.empty();",
+            "  private final String string = optional.toString();",
+            "",
+            "  void m() {",
+            "    Optional.empty().orElse(null);",
+            "    optional.orElse(null);",
+            "    optional.orElse(\"constant\");",
+            "    optional.orElse(\"constant\" + 0);",
+            "    optional.orElse(Boolean.TRUE);",
+            "    optional.orElse(string);",
+            "    optional.orElse(this.string);",
+            "    optional.orElse(Refaster.anyOf(\"constant\", \"another\"));",
+            "    Optional.<Supplier<String>>empty().orElse(() -> \"constant\");",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    Optional.empty().orElse(string + \"constant\");",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(string + \"constant\");",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(\"constant\".toString());",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(string.toString());",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(this.string.toString());",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(String.valueOf(42));",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(string.toString().length());",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(\"constant\".equals(string));",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(string.equals(string));",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(this.string.equals(string));",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(foo());",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(this.foo());",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(new Object() {});",
+            "    // BUG: Diagnostic contains:",
+            "    optional.orElse(new int[0].length);",
+            "  }",
+            "",
+            "  private <T> T foo() {",
+            "    return null;",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    BugCheckerRefactoringTestHelper.newInstance(OptionalOrElseGet.class, getClass())
+        .addInputLines(
+            "A.java",
+            "import java.util.Optional;",
+            "",
+            "class A {",
+            "  private final Optional<Object> optional = Optional.empty();",
+            "  private final String string = optional.toString();",
+            "",
+            "  void m() {",
+            "    optional.orElse(string + \"constant\");",
+            "    optional.orElse(\"constant\".toString());",
+            "    optional.orElse(string.toString());",
+            "    optional.orElse(this.string.toString());",
+            "    optional.orElse(String.valueOf(42));",
+            "    optional.orElse(string.toString().length());",
+            "    optional.orElse(string.equals(string));",
+            "    optional.orElse(foo());",
+            "    optional.orElse(this.<Number>foo());",
+            "    optional.orElse(this.<String, Integer>bar());",
+            "    optional.orElse(new Object() {});",
+            "    optional.orElse(new int[0].length);",
+            "  }",
+            "",
+            "  private <T> T foo() {",
+            "    return null;",
+            "  }",
+            "",
+            "  private <S, T> T bar() {",
+            "    return null;",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import java.util.Optional;",
+            "",
+            "class A {",
+            "  private final Optional<Object> optional = Optional.empty();",
+            "  private final String string = optional.toString();",
+            "",
+            "  void m() {",
+            "    optional.orElseGet(() -> string + \"constant\");",
+            "    optional.orElseGet(\"constant\"::toString);",
+            "    optional.orElseGet(string::toString);",
+            "    optional.orElseGet(this.string::toString);",
+            "    optional.orElseGet(() -> String.valueOf(42));",
+            "    optional.orElseGet(() -> string.toString().length());",
+            "    optional.orElseGet(() -> string.equals(string));",
+            "    optional.orElseGet(() -> foo());",
+            "    optional.orElseGet(this::<Number>foo);",
+            "    optional.orElseGet(this::<String, Integer>bar);",
+            "    optional.orElseGet(() -> new Object() {});",
+            "    optional.orElseGet(() -> new int[0].length);",
+            "  }",
+            "",
+            "  private <T> T foo() {",
+            "    return null;",
+            "  }",
+            "",
+            "  private <S, T> T bar() {",
+            "    return null;",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/Slf4jLogStatementTest.java

@@ -19,7 +19,6 @@ final class Slf4jLogStatementTest {
             "class A {",
             "  private static final String FMT0 = \"format-string-without-placeholders\";",
             "  private static final String FMT1 = \"format-string-with-{}-placeholder\";",
-            "  private static final String FMT2 = \"format-string-with-{}-{}-placeholders\";",
             "  private static final String FMT_ERR = \"format-string-with-%s-placeholder\";",
             "  private static final Logger LOG = LoggerFactory.getLogger(A.class);",
             "",

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ClassRulesTestInput.java

@@ -1,26 +1,34 @@
 package tech.picnic.errorprone.refasterrules;
 
 import com.google.common.collect.ImmutableSet;
-import java.io.IOException;
+import java.util.function.Function;
 import java.util.function.Predicate;
 import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 
 final class ClassRulesTest implements RefasterRuleCollectionTestCase {
-  boolean testClassIsInstance() throws IOException {
+  boolean testClassIsInstance() {
     return CharSequence.class.isAssignableFrom("foo".getClass());
   }
 
-  ImmutableSet<Boolean> testInstanceof() throws IOException {
+  ImmutableSet<Boolean> testInstanceof() {
     Class<?> clazz = CharSequence.class;
     return ImmutableSet.of(CharSequence.class.isInstance("foo"), clazz.isInstance("bar"));
   }
 
-  Predicate<String> testClassLiteralIsInstancePredicate() throws IOException {
+  Predicate<String> testClassLiteralIsInstancePredicate() {
     return s -> s instanceof CharSequence;
   }
 
-  Predicate<String> testClassReferenceIsInstancePredicate() throws IOException {
+  Predicate<String> testClassReferenceIsInstancePredicate() {
     Class<?> clazz = CharSequence.class;
     return s -> clazz.isInstance(s);
   }
+
+  Function<Number, Integer> testClassLiteralCast() {
+    return i -> (Integer) i;
+  }
+
+  Function<Number, Integer> testClassReferenceCast() {
+    return i -> Integer.class.cast(i);
+  }
 }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ClassRulesTestOutput.java

@@ -1,26 +1,34 @@
 package tech.picnic.errorprone.refasterrules;
 
 import com.google.common.collect.ImmutableSet;
-import java.io.IOException;
+import java.util.function.Function;
 import java.util.function.Predicate;
 import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 
 final class ClassRulesTest implements RefasterRuleCollectionTestCase {
-  boolean testClassIsInstance() throws IOException {
+  boolean testClassIsInstance() {
     return CharSequence.class.isInstance("foo");
   }
 
-  ImmutableSet<Boolean> testInstanceof() throws IOException {
+  ImmutableSet<Boolean> testInstanceof() {
     Class<?> clazz = CharSequence.class;
     return ImmutableSet.of("foo" instanceof CharSequence, clazz.isInstance("bar"));
   }
 
-  Predicate<String> testClassLiteralIsInstancePredicate() throws IOException {
+  Predicate<String> testClassLiteralIsInstancePredicate() {
     return CharSequence.class::isInstance;
   }
 
-  Predicate<String> testClassReferenceIsInstancePredicate() throws IOException {
+  Predicate<String> testClassReferenceIsInstancePredicate() {
     Class<?> clazz = CharSequence.class;
     return clazz::isInstance;
   }
+
+  Function<Number, Integer> testClassLiteralCast() {
+    return Integer.class::cast;
+  }
+
+  Function<Number, Integer> testClassReferenceCast() {
+    return Integer.class::cast;
+  }
 }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/CollectionRulesTestInput.java

@@ -6,9 +6,11 @@ import com.google.common.collect.ImmutableSortedSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedList;
+import java.util.List;
 import java.util.Optional;
 import java.util.TreeSet;
 import java.util.stream.Stream;
@@ -70,6 +72,10 @@ final class CollectionRulesTest implements RefasterRuleCollectionTestCase {
     }
   }
 
+  Stream<Integer> testSetStream() {
+    return ImmutableSet.of(1).stream().distinct();
+  }
+
   ArrayList<String> testNewArrayListFromCollection() {
     return Lists.newArrayList(ImmutableList.of("foo"));
   }
@@ -94,6 +100,10 @@ final class CollectionRulesTest implements RefasterRuleCollectionTestCase {
     return ImmutableSet.of(1).asList().toString();
   }
 
+  List<String> testArraysAsList() {
+    return Arrays.stream(new String[0]).toList();
+  }
+
   ImmutableSet<Object[]> testCollectionToArray() {
     return ImmutableSet.of(
         ImmutableSet.of(1).toArray(new Object[1]),

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/CollectionRulesTestOutput.java

@@ -6,9 +6,11 @@ import com.google.common.collect.ImmutableSortedSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedList;
+import java.util.List;
 import java.util.Optional;
 import java.util.TreeSet;
 import java.util.stream.Stream;
@@ -62,6 +64,10 @@ final class CollectionRulesTest implements RefasterRuleCollectionTestCase {
     new HashSet<Number>().removeAll(ImmutableSet.of(2));
   }
 
+  Stream<Integer> testSetStream() {
+    return ImmutableSet.of(1).stream();
+  }
+
   ArrayList<String> testNewArrayListFromCollection() {
     return new ArrayList<>(ImmutableList.of("foo"));
   }
@@ -86,6 +92,10 @@ final class CollectionRulesTest implements RefasterRuleCollectionTestCase {
     return ImmutableSet.of(1).toString();
   }
 
+  List<String> testArraysAsList() {
+    return Arrays.asList(new String[0]);
+  }
+
   ImmutableSet<Object[]> testCollectionToArray() {
     return ImmutableSet.of(
         ImmutableSet.of(1).toArray(), ImmutableSet.of(2).toArray(), ImmutableSet.of(3).toArray());

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ComparatorRulesTestInput.java

@@ -9,6 +9,7 @@ import static java.util.stream.Collectors.minBy;
 import com.google.common.collect.Comparators;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
+import java.math.RoundingMode;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Comparator;
@@ -54,6 +55,10 @@ final class ComparatorRulesTest implements RefasterRuleCollectionTestCase {
         Comparator.comparing(s -> "foo", Comparator.comparingInt(String::length)));
   }
 
+  Comparator<String> testComparingEnum() {
+    return Comparator.comparingInt(s -> RoundingMode.valueOf(s).ordinal());
+  }
+
   Comparator<String> testThenComparing() {
     return Comparator.<String>naturalOrder().thenComparing(Comparator.comparing(String::isEmpty));
   }
@@ -102,6 +107,24 @@ final class ComparatorRulesTest implements RefasterRuleCollectionTestCase {
         Comparator.<String>reverseOrder().compare("baz", "qux"));
   }
 
+  void testCollectionsSort() {
+    Collections.sort(ImmutableList.of("foo", "bar"), naturalOrder());
+  }
+
+  ImmutableSet<String> testCollectionsMin() {
+    return ImmutableSet.of(
+        Collections.min(ImmutableList.of("foo"), naturalOrder()),
+        Collections.max(ImmutableList.of("bar"), reverseOrder()));
+  }
+
+  String testMinOfArray() {
+    return Arrays.stream(new String[0]).min(naturalOrder()).orElseThrow();
+  }
+
+  String testCollectionsMinWithComparator() {
+    return ImmutableSet.of("foo", "bar").stream().min(naturalOrder()).orElseThrow();
+  }
+
   int testMinOfVarargs() {
     return Stream.of(1, 2).min(naturalOrder()).orElseThrow();
   }
@@ -130,6 +153,20 @@ final class ComparatorRulesTest implements RefasterRuleCollectionTestCase {
         Collections.min(ImmutableSet.of("a", "b"), (a, b) -> 1));
   }
 
+  ImmutableSet<String> testCollectionsMax() {
+    return ImmutableSet.of(
+        Collections.max(ImmutableList.of("foo"), naturalOrder()),
+        Collections.min(ImmutableList.of("bar"), reverseOrder()));
+  }
+
+  String testMaxOfArray() {
+    return Arrays.stream(new String[0]).max(naturalOrder()).orElseThrow();
+  }
+
+  String testCollectionsMaxWithComparator() {
+    return ImmutableSet.of("foo", "bar").stream().max(naturalOrder()).orElseThrow();
+  }
+
   int testMaxOfVarargs() {
     return Stream.of(1, 2).max(naturalOrder()).orElseThrow();
   }
@@ -173,4 +210,16 @@ final class ComparatorRulesTest implements RefasterRuleCollectionTestCase {
   Collector<Integer, ?, Optional<Integer>> testMaxByNaturalOrder() {
     return minBy(reverseOrder());
   }
+
+  ImmutableSet<Boolean> testIsLessThan() {
+    return ImmutableSet.of(
+        RoundingMode.UP.ordinal() < RoundingMode.DOWN.ordinal(),
+        RoundingMode.UP.ordinal() >= RoundingMode.DOWN.ordinal());
+  }
+
+  ImmutableSet<Boolean> testIsLessThanOrEqualTo() {
+    return ImmutableSet.of(
+        RoundingMode.UP.ordinal() <= RoundingMode.DOWN.ordinal(),
+        RoundingMode.UP.ordinal() > RoundingMode.DOWN.ordinal());
+  }
 }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ComparatorRulesTestOutput.java

@@ -1,5 +1,6 @@
 package tech.picnic.errorprone.refasterrules;
 
+import static java.util.Comparator.comparing;
 import static java.util.Comparator.naturalOrder;
 import static java.util.Comparator.reverseOrder;
 import static java.util.function.Function.identity;
@@ -9,6 +10,7 @@ import static java.util.stream.Collectors.minBy;
 import com.google.common.collect.Comparators;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
+import java.math.RoundingMode;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Comparator;
@@ -52,6 +54,10 @@ final class ComparatorRulesTest implements RefasterRuleCollectionTestCase {
         Comparator.comparing(s -> "foo", Comparator.comparingInt(String::length)));
   }
 
+  Comparator<String> testComparingEnum() {
+    return comparing(s -> RoundingMode.valueOf(s));
+  }
+
   Comparator<String> testThenComparing() {
     return Comparator.<String>naturalOrder().thenComparing(String::isEmpty);
   }
@@ -92,6 +98,23 @@ final class ComparatorRulesTest implements RefasterRuleCollectionTestCase {
     return ImmutableSet.of("foo".compareTo("bar"), "qux".compareTo("baz"));
   }
 
+  void testCollectionsSort() {
+    Collections.sort(ImmutableList.of("foo", "bar"));
+  }
+
+  ImmutableSet<String> testCollectionsMin() {
+    return ImmutableSet.of(
+        Collections.min(ImmutableList.of("foo")), Collections.min(ImmutableList.of("bar")));
+  }
+
+  String testMinOfArray() {
+    return Collections.min(Arrays.asList(new String[0]), naturalOrder());
+  }
+
+  String testCollectionsMinWithComparator() {
+    return Collections.min(ImmutableSet.of("foo", "bar"), naturalOrder());
+  }
+
   int testMinOfVarargs() {
     return Collections.min(Arrays.asList(1, 2), naturalOrder());
   }
@@ -120,6 +143,19 @@ final class ComparatorRulesTest implements RefasterRuleCollectionTestCase {
         Comparators.min("a", "b", (a, b) -> 1));
   }
 
+  ImmutableSet<String> testCollectionsMax() {
+    return ImmutableSet.of(
+        Collections.max(ImmutableList.of("foo")), Collections.max(ImmutableList.of("bar")));
+  }
+
+  String testMaxOfArray() {
+    return Collections.max(Arrays.asList(new String[0]), naturalOrder());
+  }
+
+  String testCollectionsMaxWithComparator() {
+    return Collections.max(ImmutableSet.of("foo", "bar"), naturalOrder());
+  }
+
   int testMaxOfVarargs() {
     return Collections.max(Arrays.asList(1, 2), naturalOrder());
   }
@@ -163,4 +199,16 @@ final class ComparatorRulesTest implements RefasterRuleCollectionTestCase {
   Collector<Integer, ?, Optional<Integer>> testMaxByNaturalOrder() {
     return maxBy(naturalOrder());
   }
+
+  ImmutableSet<Boolean> testIsLessThan() {
+    return ImmutableSet.of(
+        RoundingMode.UP.compareTo(RoundingMode.DOWN) < 0,
+        RoundingMode.UP.compareTo(RoundingMode.DOWN) >= 0);
+  }
+
+  ImmutableSet<Boolean> testIsLessThanOrEqualTo() {
+    return ImmutableSet.of(
+        RoundingMode.UP.compareTo(RoundingMode.DOWN) <= 0,
+        RoundingMode.UP.compareTo(RoundingMode.DOWN) > 0);
+  }
 }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestInput.java

@@ -1,5 +1,6 @@
 package tech.picnic.errorprone.refasterrules;
 
+import static java.util.function.Predicate.isEqual;
 import static java.util.function.Predicate.not;
 
 import com.google.common.collect.BoundType;
@@ -14,15 +15,21 @@ import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 final class EqualityRulesTest implements RefasterRuleCollectionTestCase {
   @Override
   public ImmutableSet<Object> elidedTypesAndStaticImports() {
-    return ImmutableSet.of(Objects.class, Optional.class, not(null));
+    return ImmutableSet.of(Objects.class, Optional.class, isEqual(null), not(null));
   }
 
-  ImmutableSet<Boolean> testPrimitiveOrReferenceEquality() {
+  ImmutableSet<Boolean> testEnumReferenceEquality() {
     return ImmutableSet.of(
         RoundingMode.UP.equals(RoundingMode.DOWN),
         Objects.equals(RoundingMode.UP, RoundingMode.DOWN),
+        RoundingMode.UP.ordinal() == RoundingMode.DOWN.ordinal(),
         !RoundingMode.UP.equals(RoundingMode.DOWN),
-        !Objects.equals(RoundingMode.UP, RoundingMode.DOWN));
+        !Objects.equals(RoundingMode.UP, RoundingMode.DOWN),
+        RoundingMode.UP.ordinal() != RoundingMode.DOWN.ordinal());
+  }
+
+  ImmutableSet<Predicate<RoundingMode>> testEnumReferenceEqualityLambda() {
+    return ImmutableSet.of(isEqual(RoundingMode.DOWN), RoundingMode.UP::equals);
   }
 
   boolean testEqualsPredicate() {

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestOutput.java

@@ -1,5 +1,6 @@
 package tech.picnic.errorprone.refasterrules;
 
+import static java.util.function.Predicate.isEqual;
 import static java.util.function.Predicate.not;
 
 import com.google.common.collect.BoundType;
@@ -14,17 +15,23 @@ import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 final class EqualityRulesTest implements RefasterRuleCollectionTestCase {
   @Override
   public ImmutableSet<Object> elidedTypesAndStaticImports() {
-    return ImmutableSet.of(Objects.class, Optional.class, not(null));
+    return ImmutableSet.of(Objects.class, Optional.class, isEqual(null), not(null));
   }
 
-  ImmutableSet<Boolean> testPrimitiveOrReferenceEquality() {
+  ImmutableSet<Boolean> testEnumReferenceEquality() {
     return ImmutableSet.of(
         RoundingMode.UP == RoundingMode.DOWN,
         RoundingMode.UP == RoundingMode.DOWN,
+        RoundingMode.UP == RoundingMode.DOWN,
+        RoundingMode.UP != RoundingMode.DOWN,
         RoundingMode.UP != RoundingMode.DOWN,
         RoundingMode.UP != RoundingMode.DOWN);
   }
 
+  ImmutableSet<Predicate<RoundingMode>> testEnumReferenceEqualityLambda() {
+    return ImmutableSet.of(v -> v == RoundingMode.DOWN, v -> v == RoundingMode.UP);
+  }
+
   boolean testEqualsPredicate() {
     // XXX: When boxing is involved this rule seems to break. Example:
     // Stream.of(1).anyMatch(e -> Integer.MIN_VALUE.equals(e));

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/FileRulesTestInput.java

@@ -1,12 +1,28 @@
 package tech.picnic.errorprone.refasterrules;
 
+import com.google.common.collect.ImmutableSet;
+import java.io.File;
 import java.io.IOException;
+import java.net.URI;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
+import java.nio.file.Path;
 import java.nio.file.Paths;
 import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 
 final class FileRulesTest implements RefasterRuleCollectionTestCase {
+  Path testPathOfUri() {
+    return Paths.get(URI.create("foo"));
+  }
+
+  ImmutableSet<Path> testPathOfString() {
+    return ImmutableSet.of(Paths.get("foo"), Paths.get("bar", "baz", "qux"));
+  }
+
+  Path testPathInstance() {
+    return Path.of("foo").toFile().toPath();
+  }
+
   String testFilesReadStringWithCharset() throws IOException {
     return new String(Files.readAllBytes(Paths.get("foo")), StandardCharsets.ISO_8859_1);
   }
@@ -14,4 +30,13 @@ final class FileRulesTest implements RefasterRuleCollectionTestCase {
   String testFilesReadString() throws IOException {
     return Files.readString(Paths.get("foo"), StandardCharsets.UTF_8);
   }
+
+  ImmutableSet<File> testFilesCreateTempFileToFile() throws IOException {
+    return ImmutableSet.of(
+        File.createTempFile("foo", "bar"), File.createTempFile("baz", "qux", null));
+  }
+
+  File testFilesCreateTempFileInCustomDirectoryToFile() throws IOException {
+    return File.createTempFile("foo", "bar", new File("baz"));
+  }
 }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/FileRulesTestOutput.java

@@ -1,12 +1,28 @@
 package tech.picnic.errorprone.refasterrules;
 
+import com.google.common.collect.ImmutableSet;
+import java.io.File;
 import java.io.IOException;
+import java.net.URI;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
+import java.nio.file.Path;
 import java.nio.file.Paths;
 import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 
 final class FileRulesTest implements RefasterRuleCollectionTestCase {
+  Path testPathOfUri() {
+    return Path.of(URI.create("foo"));
+  }
+
+  ImmutableSet<Path> testPathOfString() {
+    return ImmutableSet.of(Path.of("foo"), Path.of("bar", "baz", "qux"));
+  }
+
+  Path testPathInstance() {
+    return Path.of("foo");
+  }
+
   String testFilesReadStringWithCharset() throws IOException {
     return Files.readString(Paths.get("foo"), StandardCharsets.ISO_8859_1);
   }
@@ -14,4 +30,13 @@ final class FileRulesTest implements RefasterRuleCollectionTestCase {
   String testFilesReadString() throws IOException {
     return Files.readString(Paths.get("foo"));
   }
+
+  ImmutableSet<File> testFilesCreateTempFileToFile() throws IOException {
+    return ImmutableSet.of(
+        Files.createTempFile("foo", "bar").toFile(), Files.createTempFile("baz", "qux").toFile());
+  }
+
+  File testFilesCreateTempFileInCustomDirectoryToFile() throws IOException {
+    return Files.createTempFile(new File("baz").toPath(), "foo", "bar").toFile();
+  }
 }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ImmutableMultisetRulesTestInput.java

@@ -26,6 +26,7 @@ final class ImmutableMultisetRulesTest implements RefasterRuleCollectionTestCase
         Stream.<Integer>empty().collect(toImmutableMultiset()));
   }
 
+  @SuppressWarnings("unchecked")
   ImmutableMultiset<ImmutableMultiset<Integer>> testIterableToImmutableMultiset() {
     return ImmutableMultiset.of(
         ImmutableList.of(1).stream().collect(toImmutableMultiset()),

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ImmutableMultisetRulesTestOutput.java

@@ -24,6 +24,7 @@ final class ImmutableMultisetRulesTest implements RefasterRuleCollectionTestCase
     return ImmutableMultiset.of(ImmutableMultiset.of(), ImmutableMultiset.of());
   }
 
+  @SuppressWarnings("unchecked")
   ImmutableMultiset<ImmutableMultiset<Integer>> testIterableToImmutableMultiset() {
     return ImmutableMultiset.of(
         ImmutableMultiset.copyOf(ImmutableList.of(1)),

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ImmutableSortedMultisetRulesTestInput.java

@@ -37,6 +37,7 @@ final class ImmutableSortedMultisetRulesTest implements RefasterRuleCollectionTe
         Stream.<Integer>empty().collect(toImmutableSortedMultiset(naturalOrder())));
   }
 
+  @SuppressWarnings("unchecked")
   ImmutableMultiset<ImmutableSortedMultiset<Integer>> testIterableToImmutableSortedMultiset() {
     return ImmutableMultiset.of(
         ImmutableSortedMultiset.copyOf(naturalOrder(), ImmutableList.of(1)),

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ImmutableSortedMultisetRulesTestOutput.java

@@ -35,6 +35,7 @@ final class ImmutableSortedMultisetRulesTest implements RefasterRuleCollectionTe
     return ImmutableMultiset.of(ImmutableSortedMultiset.of(), ImmutableSortedMultiset.of());
   }
 
+  @SuppressWarnings("unchecked")
   ImmutableMultiset<ImmutableSortedMultiset<Integer>> testIterableToImmutableSortedMultiset() {
     return ImmutableMultiset.of(
         ImmutableSortedMultiset.copyOf(ImmutableList.of(1)),

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/JUnitToAssertJRulesTestInput.java

@@ -32,8 +32,8 @@ final class JUnitToAssertJRulesTest implements RefasterRuleCollectionTestCase {
         (Runnable) () -> assertTrue(true));
   }
 
-  void testThrowNewAssertionError() {
-    Assertions.fail();
+  Object testFail() {
+    return Assertions.fail();
   }
 
   Object testFailWithMessage() {
@@ -44,8 +44,8 @@ final class JUnitToAssertJRulesTest implements RefasterRuleCollectionTestCase {
     return Assertions.fail("foo", new IllegalStateException());
   }
 
-  void testFailWithThrowable() {
-    Assertions.fail(new IllegalStateException());
+  Object testFailWithThrowable() {
+    return Assertions.fail(new IllegalStateException());
   }
 
   void testAssertThatIsTrue() {

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/JUnitToAssertJRulesTestOutput.java

@@ -35,8 +35,8 @@ final class JUnitToAssertJRulesTest implements RefasterRuleCollectionTestCase {
         (Runnable) () -> assertTrue(true));
   }
 
-  void testThrowNewAssertionError() {
-    throw new AssertionError();
+  Object testFail() {
+    return org.assertj.core.api.Assertions.fail();
   }
 
   Object testFailWithMessage() {
@@ -47,8 +47,8 @@ final class JUnitToAssertJRulesTest implements RefasterRuleCollectionTestCase {
     return org.assertj.core.api.Assertions.fail("foo", new IllegalStateException());
   }
 
-  void testFailWithThrowable() {
-    throw new AssertionError(new IllegalStateException());
+  Object testFailWithThrowable() {
+    return org.assertj.core.api.Assertions.fail(new IllegalStateException());
   }
 
   void testAssertThatIsTrue() {

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/OptionalRulesTestInput.java

@@ -13,6 +13,10 @@ final class OptionalRulesTest implements RefasterRuleCollectionTestCase {
     return ImmutableSet.of(Streams.class);
   }
 
+  Optional<String> testOptionalEmpty() {
+    return Optional.ofNullable(null);
+  }
+
   ImmutableSet<Optional<String>> testOptionalOfNullable() {
     return ImmutableSet.of(
         toString() == null ? Optional.empty() : Optional.of(toString()),
@@ -79,11 +83,9 @@ final class OptionalRulesTest implements RefasterRuleCollectionTestCase {
     return Optional.of("foo").orElseGet(() -> Optional.of("bar").orElseThrow());
   }
 
-  ImmutableSet<String> testOptionalOrElseGet() {
+  ImmutableSet<String> testOptionalOrElse() {
     return ImmutableSet.of(
-        Optional.of("foo").orElse("bar"),
-        Optional.of("baz").orElse(toString()),
-        Optional.of("qux").orElse(String.valueOf(true)));
+        Optional.of("foo").orElseGet(() -> "bar"), Optional.of("baz").orElseGet(() -> toString()));
   }
 
   ImmutableSet<Object> testStreamFlatMapOptional() {
@@ -120,10 +122,12 @@ final class OptionalRulesTest implements RefasterRuleCollectionTestCase {
     return ImmutableSet.of(
         Optional.of("foo").or(() -> Optional.empty()),
         Optional.of("bar").or(Optional::empty),
-        Optional.of("baz").stream().findFirst(),
-        Optional.of("qux").stream().findAny(),
-        Optional.of("quux").stream().min(String::compareTo),
-        Optional.of("quuz").stream().max(String::compareTo));
+        Optional.of("baz").map(Optional::of).orElseGet(() -> Optional.empty()),
+        Optional.of("qux").map(Optional::of).orElseGet(Optional::empty),
+        Optional.of("quux").stream().findFirst(),
+        Optional.of("quuz").stream().findAny(),
+        Optional.of("corge").stream().min(String::compareTo),
+        Optional.of("grault").stream().max(String::compareTo));
   }
 
   ImmutableSet<Optional<String>> testOptionalFilter() {
@@ -136,9 +140,7 @@ final class OptionalRulesTest implements RefasterRuleCollectionTestCase {
     return Optional.of(1).stream().map(String::valueOf).findAny();
   }
 
-  ImmutableSet<Stream<String>> testOptionalStream() {
-    return ImmutableSet.of(
-        Optional.of("foo").map(Stream::of).orElse(Stream.empty()),
-        Optional.of("bar").map(Stream::of).orElseGet(Stream::empty));
+  Stream<String> testOptionalStream() {
+    return Optional.of("foo").map(Stream::of).orElseGet(Stream::empty);
   }
 }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/OptionalRulesTestOutput.java

@@ -15,6 +15,10 @@ final class OptionalRulesTest implements RefasterRuleCollectionTestCase {
     return ImmutableSet.of(Streams.class);
   }
 
+  Optional<String> testOptionalEmpty() {
+    return Optional.empty();
+  }
+
   ImmutableSet<Optional<String>> testOptionalOfNullable() {
     return ImmutableSet.of(Optional.ofNullable(toString()), Optional.ofNullable(toString()));
   }
@@ -76,11 +80,9 @@ final class OptionalRulesTest implements RefasterRuleCollectionTestCase {
     return Optional.of("foo").or(() -> Optional.of("bar")).orElseThrow();
   }
 
-  ImmutableSet<String> testOptionalOrElseGet() {
+  ImmutableSet<String> testOptionalOrElse() {
     return ImmutableSet.of(
-        Optional.of("foo").orElse("bar"),
-        Optional.of("baz").orElse(toString()),
-        Optional.of("qux").orElseGet(() -> String.valueOf(true)));
+        Optional.of("foo").orElse("bar"), Optional.of("baz").orElseGet(() -> toString()));
   }
 
   ImmutableSet<Object> testStreamFlatMapOptional() {
@@ -120,7 +122,9 @@ final class OptionalRulesTest implements RefasterRuleCollectionTestCase {
         Optional.of("baz"),
         Optional.of("qux"),
         Optional.of("quux"),
-        Optional.of("quuz"));
+        Optional.of("quuz"),
+        Optional.of("corge"),
+        Optional.of("grault"));
   }
 
   ImmutableSet<Optional<String>> testOptionalFilter() {
@@ -132,7 +136,7 @@ final class OptionalRulesTest implements RefasterRuleCollectionTestCase {
     return Optional.of(1).map(String::valueOf);
   }
 
-  ImmutableSet<Stream<String>> testOptionalStream() {
-    return ImmutableSet.of(Optional.of("foo").stream(), Optional.of("bar").stream());
+  Stream<String> testOptionalStream() {
+    return Optional.of("foo").stream();
   }
 }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/PrimitiveRulesTestInput.java

@@ -9,6 +9,8 @@ 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.common.primitives.UnsignedInts;
+import com.google.common.primitives.UnsignedLongs;
 import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 
 final class PrimitiveRulesTest implements RefasterRuleCollectionTestCase {
@@ -22,7 +24,9 @@ final class PrimitiveRulesTest implements RefasterRuleCollectionTestCase {
         Floats.class,
         Ints.class,
         Longs.class,
-        Shorts.class);
+        Shorts.class,
+        UnsignedInts.class,
+        UnsignedLongs.class);
   }
 
   ImmutableSet<Boolean> testLessThan() {
@@ -105,26 +109,6 @@ final class PrimitiveRulesTest implements RefasterRuleCollectionTestCase {
     return Doubles.hashCode(1);
   }
 
-  int testBooleanCompare() {
-    return Booleans.compare(false, true);
-  }
-
-  int testCharacterCompare() {
-    return Chars.compare('a', 'b');
-  }
-
-  int testShortCompare() {
-    return Shorts.compare((short) 1, (short) 2);
-  }
-
-  int testIntegerCompare() {
-    return Ints.compare(1, 2);
-  }
-
-  int testLongCompare() {
-    return Longs.compare(1, 2);
-  }
-
   int testFloatCompare() {
     return Floats.compare(1, 2);
   }
@@ -190,4 +174,60 @@ final class PrimitiveRulesTest implements RefasterRuleCollectionTestCase {
     return ImmutableSet.of(
         Long.signum(1L) < 0, Long.signum(2L) <= -1, Long.signum(3L) >= 0, Long.signum(4L) > -1);
   }
+
+  int testIntegerCompareUnsigned() {
+    return UnsignedInts.compare(1, 2);
+  }
+
+  long testLongCompareUnsigned() {
+    return UnsignedLongs.compare(1, 2);
+  }
+
+  int testIntegerDivideUnsigned() {
+    return UnsignedInts.divide(1, 2);
+  }
+
+  long testLongDivideUnsigned() {
+    return UnsignedLongs.divide(1, 2);
+  }
+
+  int testIntegerRemainderUnsigned() {
+    return UnsignedInts.remainder(1, 2);
+  }
+
+  long testLongRemainderUnsigned() {
+    return UnsignedLongs.remainder(1, 2);
+  }
+
+  ImmutableSet<Integer> testIntegerParseUnsignedInt() {
+    return ImmutableSet.of(UnsignedInts.parseUnsignedInt("1"), Integer.parseUnsignedInt("2", 10));
+  }
+
+  ImmutableSet<Long> testLongParseUnsignedLong() {
+    return ImmutableSet.of(UnsignedLongs.parseUnsignedLong("1"), Long.parseUnsignedLong("2", 10));
+  }
+
+  int testIntegerParseUnsignedIntWithRadix() {
+    return UnsignedInts.parseUnsignedInt("1", 2);
+  }
+
+  long testLongParseUnsignedLongWithRadix() {
+    return UnsignedLongs.parseUnsignedLong("1", 2);
+  }
+
+  ImmutableSet<String> testIntegerToUnsignedString() {
+    return ImmutableSet.of(UnsignedInts.toString(1), Integer.toUnsignedString(2, 10));
+  }
+
+  ImmutableSet<String> testLongToUnsignedString() {
+    return ImmutableSet.of(UnsignedLongs.toString(1), Long.toUnsignedString(2, 10));
+  }
+
+  String testIntegerToUnsignedStringWithRadix() {
+    return UnsignedInts.toString(1, 2);
+  }
+
+  String testLongToUnsignedStringWithRadix() {
+    return UnsignedLongs.toString(1, 2);
+  }
 }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/PrimitiveRulesTestOutput.java

@@ -9,6 +9,8 @@ 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.common.primitives.UnsignedInts;
+import com.google.common.primitives.UnsignedLongs;
 import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 
 final class PrimitiveRulesTest implements RefasterRuleCollectionTestCase {
@@ -22,7 +24,9 @@ final class PrimitiveRulesTest implements RefasterRuleCollectionTestCase {
         Floats.class,
         Ints.class,
         Longs.class,
-        Shorts.class);
+        Shorts.class,
+        UnsignedInts.class,
+        UnsignedLongs.class);
   }
 
   ImmutableSet<Boolean> testLessThan() {
@@ -105,26 +109,6 @@ final class PrimitiveRulesTest implements RefasterRuleCollectionTestCase {
     return Double.hashCode(1);
   }
 
-  int testBooleanCompare() {
-    return Boolean.compare(false, true);
-  }
-
-  int testCharacterCompare() {
-    return Character.compare('a', 'b');
-  }
-
-  int testShortCompare() {
-    return Short.compare((short) 1, (short) 2);
-  }
-
-  int testIntegerCompare() {
-    return Integer.compare(1, 2);
-  }
-
-  int testLongCompare() {
-    return Long.compare(1, 2);
-  }
-
   int testFloatCompare() {
     return Float.compare(1, 2);
   }
@@ -190,4 +174,60 @@ final class PrimitiveRulesTest implements RefasterRuleCollectionTestCase {
     return ImmutableSet.of(
         Long.signum(1L) == -1, Long.signum(2L) == -1, Long.signum(3L) != -1, Long.signum(4L) != -1);
   }
+
+  int testIntegerCompareUnsigned() {
+    return Integer.compareUnsigned(1, 2);
+  }
+
+  long testLongCompareUnsigned() {
+    return Long.compareUnsigned(1, 2);
+  }
+
+  int testIntegerDivideUnsigned() {
+    return Integer.divideUnsigned(1, 2);
+  }
+
+  long testLongDivideUnsigned() {
+    return Long.divideUnsigned(1, 2);
+  }
+
+  int testIntegerRemainderUnsigned() {
+    return Integer.remainderUnsigned(1, 2);
+  }
+
+  long testLongRemainderUnsigned() {
+    return Long.remainderUnsigned(1, 2);
+  }
+
+  ImmutableSet<Integer> testIntegerParseUnsignedInt() {
+    return ImmutableSet.of(Integer.parseUnsignedInt("1"), Integer.parseUnsignedInt("2"));
+  }
+
+  ImmutableSet<Long> testLongParseUnsignedLong() {
+    return ImmutableSet.of(Long.parseUnsignedLong("1"), Long.parseUnsignedLong("2"));
+  }
+
+  int testIntegerParseUnsignedIntWithRadix() {
+    return Integer.parseUnsignedInt("1", 2);
+  }
+
+  long testLongParseUnsignedLongWithRadix() {
+    return Long.parseUnsignedLong("1", 2);
+  }
+
+  ImmutableSet<String> testIntegerToUnsignedString() {
+    return ImmutableSet.of(Integer.toUnsignedString(1), Integer.toUnsignedString(2));
+  }
+
+  ImmutableSet<String> testLongToUnsignedString() {
+    return ImmutableSet.of(Long.toUnsignedString(1), Long.toUnsignedString(2));
+  }
+
+  String testIntegerToUnsignedStringWithRadix() {
+    return Integer.toUnsignedString(1, 2);
+  }
+
+  String testLongToUnsignedStringWithRadix() {
+    return Long.toUnsignedString(1, 2);
+  }
 }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestInput.java

@@ -10,6 +10,7 @@ import static java.util.stream.Collectors.minBy;
 import static java.util.stream.Collectors.toCollection;
 import static org.assertj.core.api.Assertions.assertThat;
 
+import com.github.benmanes.caffeine.cache.AsyncLoadingCache;
 import com.google.common.collect.ImmutableCollection;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -21,7 +22,9 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.Callable;
+import java.util.concurrent.CompletableFuture;
 import java.util.function.Supplier;
+import java.util.stream.Stream;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.math.MathFlux;
@@ -142,7 +145,7 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
   }
 
   Flux<Integer> testFluxTake() {
-    return Flux.just(1, 2, 3).take(1);
+    return Flux.just(1, 2, 3).take(1, true);
   }
 
   Mono<String> testMonoDefaultIfEmpty() {
@@ -182,8 +185,8 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
         Flux.range(0, 0));
   }
 
-  Flux<Integer> testFluxJust() {
-    return Flux.range(0, 1);
+  ImmutableSet<Flux<Integer>> testFluxJust() {
+    return ImmutableSet.of(Flux.range(0, 1), Mono.just(2).repeat().take(1));
   }
 
   ImmutableSet<Mono<?>> testMonoIdentity() {
@@ -207,11 +210,12 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
 
   ImmutableSet<Flux<Integer>> testFluxConcatMap() {
     return ImmutableSet.of(
-        Flux.just(1).flatMap(Mono::just, 1),
-        Flux.just(2).flatMapSequential(Mono::just, 1),
-        Flux.just(3).map(Mono::just).concatMap(identity()),
-        Flux.just(4).map(Mono::just).concatMap(v -> v),
-        Flux.just(5).map(Mono::just).concatMap(v -> Mono.empty()));
+        Flux.just(1).concatMap(Mono::just, 0),
+        Flux.just(2).flatMap(Mono::just, 1),
+        Flux.just(3).flatMapSequential(Mono::just, 1),
+        Flux.just(4).map(Mono::just).concatMap(identity()),
+        Flux.just(5).map(Mono::just).concatMap(v -> v),
+        Flux.just(6).map(Mono::just).concatMap(v -> Mono.empty()));
   }
 
   ImmutableSet<Flux<Integer>> testFluxConcatMapWithPrefetch() {
@@ -432,6 +436,12 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
         Flux.just(ImmutableList.of("bar")).concatMap(Flux::fromIterable, 2));
   }
 
+  ImmutableSet<Flux<String>> testFluxFromIterable() {
+    return ImmutableSet.of(
+        Flux.fromStream(ImmutableList.of("foo")::stream),
+        Flux.fromStream(() -> ImmutableList.of("bar").stream()));
+  }
+
   ImmutableSet<Mono<Integer>> testFluxCountMapMathToIntExact() {
     return ImmutableSet.of(
         Flux.just(1).collect(toImmutableList()).map(Collection::size),
@@ -646,4 +656,20 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
   Duration testStepVerifierLastStepVerifyTimeout() {
     return Mono.empty().as(StepVerifier::create).expectTimeout(Duration.ZERO).verify();
   }
+
+  Mono<Void> testMonoFromFutureSupplier() {
+    return Mono.fromFuture(CompletableFuture.completedFuture(null));
+  }
+
+  Mono<Void> testMonoFromFutureSupplierBoolean() {
+    return Mono.fromFuture(CompletableFuture.completedFuture(null), true);
+  }
+
+  Mono<String> testMonoFromFutureAsyncLoadingCacheGet() {
+    return Mono.fromFuture(() -> ((AsyncLoadingCache<Integer, String>) null).get(0));
+  }
+
+  Flux<Integer> testFluxFromStreamSupplier() {
+    return Flux.fromStream(Stream.of(1));
+  }
 }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestOutput.java

@@ -12,6 +12,7 @@ import static java.util.stream.Collectors.toCollection;
 import static org.assertj.core.api.Assertions.assertThat;
 import static reactor.function.TupleUtils.function;
 
+import com.github.benmanes.caffeine.cache.AsyncLoadingCache;
 import com.google.common.collect.ImmutableCollection;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -23,7 +24,9 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.Callable;
+import java.util.concurrent.CompletableFuture;
 import java.util.function.Supplier;
+import java.util.stream.Stream;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.function.TupleUtils;
@@ -147,7 +150,7 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
   }
 
   Flux<Integer> testFluxTake() {
-    return Flux.just(1, 2, 3).take(1, true);
+    return Flux.just(1, 2, 3).take(1);
   }
 
   Mono<String> testMonoDefaultIfEmpty() {
@@ -186,8 +189,8 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
         Flux.empty());
   }
 
-  Flux<Integer> testFluxJust() {
-    return Flux.just(0);
+  ImmutableSet<Flux<Integer>> testFluxJust() {
+    return ImmutableSet.of(Flux.just(0), Flux.just(2));
   }
 
   ImmutableSet<Mono<?>> testMonoIdentity() {
@@ -214,7 +217,8 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
         Flux.just(2).concatMap(Mono::just),
         Flux.just(3).concatMap(Mono::just),
         Flux.just(4).concatMap(Mono::just),
-        Flux.just(5).map(Mono::just).concatMap(v -> Mono.empty()));
+        Flux.just(5).concatMap(Mono::just),
+        Flux.just(6).map(Mono::just).concatMap(v -> Mono.empty()));
   }
 
   ImmutableSet<Flux<Integer>> testFluxConcatMapWithPrefetch() {
@@ -427,6 +431,11 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
         Flux.just(ImmutableList.of("bar")).concatMapIterable(identity(), 2));
   }
 
+  ImmutableSet<Flux<String>> testFluxFromIterable() {
+    return ImmutableSet.of(
+        Flux.fromIterable(ImmutableList.of("foo")), Flux.fromIterable(ImmutableList.of("bar")));
+  }
+
   ImmutableSet<Mono<Integer>> testFluxCountMapMathToIntExact() {
     return ImmutableSet.of(
         Flux.just(1).count().map(Math::toIntExact),
@@ -627,4 +636,20 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
   Duration testStepVerifierLastStepVerifyTimeout() {
     return Mono.empty().as(StepVerifier::create).verifyTimeout(Duration.ZERO);
   }
+
+  Mono<Void> testMonoFromFutureSupplier() {
+    return Mono.fromFuture(() -> CompletableFuture.completedFuture(null));
+  }
+
+  Mono<Void> testMonoFromFutureSupplierBoolean() {
+    return Mono.fromFuture(() -> CompletableFuture.completedFuture(null), true);
+  }
+
+  Mono<String> testMonoFromFutureAsyncLoadingCacheGet() {
+    return Mono.fromFuture(() -> ((AsyncLoadingCache<Integer, String>) null).get(0), true);
+  }
+
+  Flux<Integer> testFluxFromStreamSupplier() {
+    return Flux.fromStream(() -> Stream.of(1));
+  }
 }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/StreamRulesTestInput.java

@@ -120,7 +120,7 @@ final class StreamRulesTest implements RefasterRuleCollectionTestCase {
         Stream.of("bar").map(String::length).findFirst());
   }
 
-  ImmutableSet<Boolean> testStreamIsEmpty() {
+  ImmutableSet<Boolean> testStreamFindAnyIsEmpty() {
     return ImmutableSet.of(
         Stream.of(1).count() == 0,
         Stream.of(2).count() <= 0,
@@ -131,15 +131,14 @@ final class StreamRulesTest implements RefasterRuleCollectionTestCase {
         Stream.of(7).collect(collectingAndThen(toImmutableList(), ImmutableList::isEmpty)),
         Stream.of(8).collect(collectingAndThen(toImmutableMap(k -> k, v -> v), Map::isEmpty)),
         Stream.of(9)
-            .collect(collectingAndThen(toImmutableMap(k -> k, v -> v), ImmutableMap::isEmpty)));
+            .collect(collectingAndThen(toImmutableMap(k -> k, v -> v), ImmutableMap::isEmpty)),
+        Stream.of(10).count() != 0,
+        Stream.of(11).count() > 0,
+        Stream.of(12).count() >= 1);
   }
 
-  ImmutableSet<Boolean> testStreamIsNotEmpty() {
-    return ImmutableSet.of(
-        Stream.of(1).count() != 0,
-        Stream.of(2).count() > 0,
-        Stream.of(3).count() >= 1,
-        Stream.of(4).findFirst().isPresent());
+  boolean testStreamFindAnyIsPresent() {
+    return Stream.of(1).findFirst().isPresent();
   }
 
   ImmutableSet<Optional<String>> testStreamMin() {

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/StreamRulesTestOutput.java

@@ -121,7 +121,7 @@ final class StreamRulesTest implements RefasterRuleCollectionTestCase {
         Stream.of("bar").findFirst().map(String::length));
   }
 
-  ImmutableSet<Boolean> testStreamIsEmpty() {
+  ImmutableSet<Boolean> testStreamFindAnyIsEmpty() {
     return ImmutableSet.of(
         Stream.of(1).findAny().isEmpty(),
         Stream.of(2).findAny().isEmpty(),
@@ -131,15 +131,14 @@ final class StreamRulesTest implements RefasterRuleCollectionTestCase {
         Stream.of(6).findAny().isEmpty(),
         Stream.of(7).findAny().isEmpty(),
         Stream.of(8).findAny().isEmpty(),
-        Stream.of(9).findAny().isEmpty());
+        Stream.of(9).findAny().isEmpty(),
+        !Stream.of(10).findAny().isEmpty(),
+        !Stream.of(11).findAny().isEmpty(),
+        !Stream.of(12).findAny().isEmpty());
   }
 
-  ImmutableSet<Boolean> testStreamIsNotEmpty() {
-    return ImmutableSet.of(
-        Stream.of(1).findAny().isPresent(),
-        Stream.of(2).findAny().isPresent(),
-        Stream.of(3).findAny().isPresent(),
-        Stream.of(4).findAny().isPresent());
+  boolean testStreamFindAnyIsPresent() {
+    return Stream.of(1).findAny().isPresent();
   }
 
   ImmutableSet<Optional<String>> testStreamMin() {

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/TestNGToAssertJRulesTestOutput.java

@@ -41,7 +41,7 @@ final class TestNGToAssertJRulesTest implements RefasterRuleCollectionTestCase {
   }
 
   void testFail() {
-    throw new AssertionError();
+    fail();
   }
 
   void testFailWithMessage() {

error-prone-experimental/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.15.1-SNAPSHOT</version>
+        <version>0.18.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>error-prone-experimental</artifactId>

error-prone-guidelines/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.15.1-SNAPSHOT</version>
+        <version>0.18.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>error-prone-guidelines</artifactId>

error-prone-utils/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.15.1-SNAPSHOT</version>
+        <version>0.18.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>error-prone-utils</artifactId>

generate-docs.sh

@@ -1,27 +0,0 @@
-#!/usr/bin/env bash
-
-set -e -u -o pipefail
-
-REPOSITORY_ROOT="$(git rev-parse --show-toplevel)"
-WEBSITE_ROOT="${REPOSITORY_ROOT}/website"
-
-generate_homepage() {
-    local homepage="${WEBSITE_ROOT}/index.md"
-
-    echo "Generating ${homepage}..."
-    cat - "${REPOSITORY_ROOT}/README.md" > "${homepage}" << EOF
----
-layout: default
-title: Home
-nav_order: 1
----
-EOF
-
-    local macos_compat=""
-    [[ "${OSTYPE}" == "darwin"* ]] && macos_compat="yes"
-    sed -i ${macos_compat:+".bak"} 's/src="website\//src="/g' "${homepage}"
-    sed -i ${macos_compat:+".bak"} 's/srcset="website\//srcset="/g' "${homepage}"
-}
-
-# Generate the website.
-generate_homepage

integration-tests/checkstyle-expected-warnings.txt

@@ -13,12 +13,16 @@ src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionAvoidNoArgument
 src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionCatchParameterNameTest.java:[166,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `enum` is not a valid identifier)
 src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionCatchParameterNameTest.java:[193,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `interface` is not a valid identifier)
 src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionEqualsAvoidNullTest.java:[39,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that a method named `equals` is already defined in this class or a supertype)
+src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionIllegalInstantiationTest.java:[91,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `interface` is not a valid identifier)
 src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionLambdaBodyLengthTest.java:[39,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
 src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionMissingJavadocTypeTest.java:[39,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `class` is not a valid identifier)
 src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionMissingOverrideTest.java:[39,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `class` is not a valid identifier)
 src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionMissingOverrideTest.java:[67,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `interface` is not a valid identifier)
+src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionMultipleStringLiteralsTest.java:[41,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
 src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionNeedBracesTest.java:[40,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `do` is not a valid identifier)
 src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionOuterTypeNumberTest.java:[39,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
+src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionParameterNumberTest.java:[39,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
+src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionSimplifyBooleanExpressionTest.java:[90,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `interface` is not a valid identifier)
 src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionUnnecessarySemicolonAfterTypeMemberDeclarationTest.java:[41,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
 src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionUnnecessarySemicolonInTryWithResourcesTest.java:[41,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
 src/test/java/com/puppycrawl/tools/checkstyle/DetailAstImplTest.java:[595,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that a method named `toString` is already defined in this class or a supertype)
@@ -48,10 +52,8 @@ src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/DefaultComesLastChec
 src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/ExplicitInitializationCheckTest.java:[36,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
 src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/FallThroughCheckTest.java:[38,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
 src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/HiddenFieldCheckTest.java:[105,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
-src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/IllegalCatchCheckTest.java:[36,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
 src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/IllegalInstantiationCheckTest.java:[48,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
 src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/IllegalThrowsCheckTest.java:[37,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
-src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/IllegalTokenCheckTest.java:[57,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `native` is not a valid identifier)
 src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/NestedIfDepthCheckTest.java:[37,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
 src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/NestedTryDepthCheckTest.java:[36,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)
 src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/NoArrayTrailingCommaCheckTest.java:[36,8] [JUnitMethodDeclaration] This method's name should not redundantly start with `test` (but note that `default` is not a valid identifier)

integration-tests/checkstyle-init.patch

@@ -1,7 +1,7 @@
 --- a/pom.xml
 +++ b/pom.xml
-@@ -362,6 +362,12 @@
-       <version>1.3.0</version>
+@@ -366,6 +366,12 @@
+       <version>1.4.1</version>
        <scope>test</scope>
      </dependency>
 +    <dependency>
@@ -13,7 +13,7 @@
      <dependency>
        <groupId>nl.jqno.equalsverifier</groupId>
        <artifactId>equalsverifier</artifactId>
-@@ -2412,6 +2418,8 @@
+@@ -2422,6 +2428,8 @@
                      <arg>
                        -Xplugin:ErrorProne ${error-prone.configuration-args}
                      </arg>
@@ -22,7 +22,7 @@
                    </compilerArgs>
                    <annotationProcessorPaths>
                      <path>
-@@ -2424,6 +2432,11 @@
+@@ -2434,6 +2442,11 @@
                        <artifactId>error-prone-contrib</artifactId>
                        <version>${error-prone-support.version}</version>
                      </path>
@@ -34,7 +34,7 @@
                    </annotationProcessorPaths>
                  </configuration>
                </execution>
-@@ -2468,9 +2481,10 @@
+@@ -2476,9 +2489,10 @@
                      <arg>-XDcompilePolicy=simple</arg>
                      <arg>
                        -Xplugin:ErrorProne \
@@ -46,7 +46,7 @@
                    </compilerArgs>
                    <annotationProcessorPaths>
                      <path>
-@@ -2483,6 +2497,11 @@
+@@ -2491,6 +2505,11 @@
                        <artifactId>error-prone-contrib</artifactId>
                        <version>${error-prone-support.version}</version>
                      </path>
@@ -69,17 +69,6 @@
      public static DetailNode parseJavadocAsDetailNode(DetailAST blockComment) {
          final JavadocDetailNodeParser parser = new JavadocDetailNodeParser();
          final ParseStatus status = parser.parseJavadocAsDetailNode(blockComment);
---- a/src/main/java/com/puppycrawl/tools/checkstyle/Main.java
-+++ b/src/main/java/com/puppycrawl/tools/checkstyle/Main.java
-@@ -626,6 +626,8 @@ public final class Main {
-             + "reported to standard out in plain format. Checkstyle requires a configuration "
-             + "XML file that configures the checks to apply.",
-             mixinStandardHelpOptions = true)
-+    // XXX: Don't reorder arguments to `picocli.CommandLine.Option#names`.
-+    @SuppressWarnings("LexicographicalAnnotationAttributeListing")
-     private static final class CliOptions {
- 
-         /** Width of CLI help option. */
 --- a/src/main/java/com/puppycrawl/tools/checkstyle/SarifLogger.java
 +++ b/src/main/java/com/puppycrawl/tools/checkstyle/SarifLogger.java
 @@ -139,6 +139,9 @@ public class SarifLogger extends AbstractAutomaticBean implements AuditListener
@@ -92,19 +81,6 @@
          final String rendered = report
              .replace(VERSION_PLACEHOLDER, String.valueOf(version))
              .replace(RESULTS_PLACEHOLDER, String.join(",\n", results));
---- a/src/main/java/com/puppycrawl/tools/checkstyle/site/SiteUtil.java
-+++ b/src/main/java/com/puppycrawl/tools/checkstyle/site/SiteUtil.java
-@@ -564,6 +564,10 @@ public final class SiteUtil {
-      * @return a set of properties for the given class.
-      */
-     public static Set<String> getPropertiesForDocumentation(Class<?> clss, Object instance) {
-+        // XXX: File PR to replace `.collect(toSet())` with `.collect(toCollection(HashSet::new))`.
-+        // XXX: Update `CollectorMutability` to recognize cases such as this one, where the created
-+        // collection is clearly modified.
-+        @SuppressWarnings("CollectorMutability")
-         final Set<String> properties =
-                 getProperties(clss).stream()
-                     .filter(prop -> {
 --- a/src/test/java/com/puppycrawl/tools/checkstyle/CheckerTest.java
 +++ b/src/test/java/com/puppycrawl/tools/checkstyle/CheckerTest.java
 @@ -93,6 +93,8 @@ import de.thetaphi.forbiddenapis.SuppressForbidden;
@@ -147,21 +123,9 @@
              final Object test = new PackageObjectFactory(Collections.singleton(null), classLoader,
                      TRY_IN_ALL_REGISTERED_PACKAGES);
              assertWithMessage("Exception is expected but got " + test).fail();
---- a/src/test/java/com/puppycrawl/tools/checkstyle/PropertyCacheFileTest.java
-+++ b/src/test/java/com/puppycrawl/tools/checkstyle/PropertyCacheFileTest.java
-@@ -429,6 +429,9 @@ public class PropertyCacheFileTest extends AbstractPathTestSupport {
-      *                     mock toByteArray to throw exception.
-      */
-     @Test
-+    // XXX: Drop suppression once
-+    // https://github.com/checkstyle/checkstyle/pull/14362 is resolved.
-+    @SuppressWarnings("InputStreamReadAllBytes")
-     public void testNonExistentResource() throws IOException {
-         final Configuration config = new DefaultConfiguration("myName");
-         final String filePath = File.createTempFile("junit", null, temporaryFolder).getPath();
 --- a/src/test/java/com/puppycrawl/tools/checkstyle/TreeWalkerTest.java
 +++ b/src/test/java/com/puppycrawl/tools/checkstyle/TreeWalkerTest.java
-@@ -81,6 +81,8 @@ import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
+@@ -80,6 +80,8 @@ import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
   * @noinspectionreason ClassWithTooManyDependencies - complex tests require a
   *      large number of imports
   */

integration-tests/checkstyle.sh

@@ -2,203 +2,35 @@
 
 set -e -u -o pipefail
 
-integration_test_root="$(cd "$(dirname -- "${0}")" && pwd)"
-error_prone_support_root="${integration_test_root}/.."
-repos_root="${integration_test_root}/.repos"
-
 test_name="$(basename "${0}" .sh)"
-project=checkstyle
-repository=https://github.com/checkstyle/checkstyle.git
-revision=checkstyle-10.13.0
-
-if [ "${#}" -gt 2 ] || ([ "${#}" = 2 ] && [ "${1:---sync}" != '--sync' ]); then
-  echo "Usage: ${0} [--sync] [<report_directory>]"
-  exit 1
-fi
-do_sync="$([ "${#}" = 0 ] || [ "${1:-}" != '--sync' ] || echo 1)"
-report_directory="$([ "${#}" = 0 ] || ([ -z "${do_sync}" ] && echo "${1}") || ([ "${#}" = 1 ] || echo "${2}"))"
-
-if [ -n "${report_directory}" ]; then
-  mkdir -p "${report_directory}"
-else
-  report_directory="$(mktemp -d)"
-  trap 'rm -rf -- "${report_directory}"' INT TERM HUP EXIT
-fi
-
-case "$(uname -s)" in
-  Linux*)
-    grep_command=grep
-    sed_command=sed
-    ;;
-  Darwin*)
-    grep_command=ggrep
-    sed_command=gsed
-    ;;
-  *)
-    echo "Unsupported distribution $(uname -s) for this script."
-    exit 1
-    ;;
-esac
-
+project='checkstyle'
+repository='https://github.com/checkstyle/checkstyle.git'
+revision='checkstyle-10.14.0'
 # XXX: Configure Renovate to manage the AssertJ version declared here.
-shared_build_flags="
-  -Perror-prone-compile,error-prone-test-compile
-  -Dassertj.version=3.24.2
-  -Derror-prone.version=$(
-    mvn -f "${error_prone_support_root}" help:evaluate -Dexpression=version.error-prone -q -DforceStdout
-  )
-  -Derror-prone-support.version=$(
-    mvn -f "${error_prone_support_root}" help:evaluate -Dexpression=project.version -q -DforceStdout
-  )
-  -DadditionalSourceDirectories=\${project.basedir}\${file.separator}src\${file.separator}it\${file.separator}java,\${project.basedir}\${file.separator}src\${file.separator}xdocs-examples\${file.separator}java
-  "
-
-# XXX: Configure Renovate to manage the fmt-maven-plugin version declared here.
-# XXX: Once GitHub actions uses Maven 3.9.2+, we can inline this variable with
-# version reference `${fmt.version}`, and `-Dfmt.version=2.21.1` added to
-# `shared_build_flags`.
-format_goal='com.spotify.fmt:fmt-maven-plugin:2.21.1:format'
-
-error_prone_shared_flags='-XepExcludedPaths:(\Q${project.basedir}${file.separator}src${file.separator}\E(it|test|xdocs-examples)\Q${file.separator}resources\E|\Q${project.build.directory}${file.separator}\E).*'
-
-# XXX: Drop the `ErrorProneRuntimeClasspath` exclusion once that check resides
-# in a separate Maven module.
-error_prone_patch_flags="${error_prone_shared_flags} -XepPatchLocation:IN_PLACE -XepPatchChecks:$(
-  find "${error_prone_support_root}" -path "*/META-INF/services/com.google.errorprone.bugpatterns.BugChecker" -print0 \
-    | xargs -0 "${grep_command}" -hoP '[^.]+$' \
-    | "${grep_command}" -v ErrorProneRuntimeClasspath \
-    | paste -s -d ',' -
-)"
-
-# XXX: Drop the `ErrorProneRuntimeClasspath` exclusion once that check resides
-# in a separate Maven module.
-error_prone_validation_flags="${error_prone_shared_flags} -XepDisableAllChecks $(
-  find "${error_prone_support_root}" -path "*/META-INF/services/com.google.errorprone.bugpatterns.BugChecker" -print0 \
-    | xargs -0 "${grep_command}" -hoP '[^.]+$' \
-    | "${sed_command}" -r 's,(.*),-Xep:\1:WARN,' \
-    | "${grep_command}" -v ErrorProneRuntimeClasspath \
-    | paste -s -d ' ' -
-)"
-
-echo "Shared build flags: ${shared_build_flags}"
-echo "Error Prone patch flags: ${error_prone_patch_flags}"
-echo "Error Prone validation flags: ${error_prone_validation_flags}"
-
-mkdir -p "${repos_root}"
-
-# Make sure that the targeted tag of the project's Git repository is checked
-# out.
-project_root="${repos_root}/${project}"
-if [ ! -d "${project_root}" ]; then
-  # The repository has not yet been cloned; create a shallow clone.
-  git clone --branch "${revision}" --depth 1 "${repository}" "${project_root}"
-else
-  # The repository does already appear to exist. Try to check out the requested
-  # tag if possible, and fetch it otherwise.
-  #
-  # Under certain circumstances this does not cause the relevant tag to be
-  # created, so if necessary we manually create it.
-  git -C "${project_root}" checkout --force "${revision}" 2>/dev/null \
-    || (
-         git -C "${project_root}" fetch --depth 1 "${repository}" "${revision}" \
-           && git -C "${project_root}" checkout --force FETCH_HEAD \
-           && (git -C "${project_root}" tag "${revision}" || true)
-       )
-fi
-
-pushd "${project_root}"
-
-# Make sure that Git is sufficiently configured to enable committing to the
-# project's Git repository.
-git config user.email || git config user.email "integration-test@example.com"
-git config user.name || git config user.name "Integration Test"
-
-# Prepare the code for analysis by (a) applying the minimal set of changes
-# required to run Error Prone with Error Prone Support and (b) formatting the
-# code using the same method by which it will be formatted after each
-# compilation round. The initial formatting operation ensures that subsequent
-# modifications can be rendered in a clean manner.
-git clean -fdx
-git apply < "${integration_test_root}/${test_name}-init.patch"
-git commit -m 'dependency: Introduce Error Prone Support' .
-mvn ${shared_build_flags} "${format_goal}"
-git commit -m 'minor: Reformat using Google Java Format' .
-diff_base="$(git rev-parse HEAD)"
-
-# Apply Error Prone Support-suggested changes until a fixed point is reached.
-function apply_patch() {
-  local extra_build_args="${1}"
-
-  mvn ${shared_build_flags} ${extra_build_args} \
-    package "${format_goal}" \
-    -Derror-prone.configuration-args="${error_prone_patch_flags}" \
-    -DskipTests
-
-  if ! git diff --exit-code; then
-    git commit -m 'minor: Apply patches' .
-
-    # Changes were applied, so another compilation round may apply yet more
-    # changes. For performance reasons we perform incremental compilation,
-    # enabled using a misleading flag. (See
-    # https://issues.apache.org/jira/browse/MCOMPILER-209 for details.)
-    apply_patch '-Dmaven.compiler.useIncrementalCompilation=false'
-  elif [ "${extra_build_args}" != 'clean' ]; then
-    # No changes were applied. We'll attempt one more round in which all files
-    # are recompiled, because there are cases in which violations are missed
-    # during incremental compilation.
-    apply_patch 'clean'
-  fi
-}
-apply_patch ''
-
-# Run one more full build and log the output.
-#
-# By also running the tests, we validate that the (majority of) applied changes
-# are behavior preserving. Some tests are skipped:
+additional_build_flags='-Dassertj.version=3.24.2'
+additional_source_directories='${project.basedir}${file.separator}src${file.separator}it${file.separator}java,${project.basedir}${file.separator}src${file.separator}xdocs-examples${file.separator}java'
+patch_error_prone_flags=''
+validation_error_prone_flags=''
+# Validation skips some tests:
 # - The `metadataFilesGenerationAllFiles` test is skipped because it makes line
 #   number assertions that will fail when the code is formatted or patched.
-# - The `allCheckSectionJavaDocs` test is skipped because is validates that
+# - The `allCheckSectionJavaDocs` test is skipped because it validates that
 #   Javadoc has certain closing tags that are removed by Google Java Format.
-validation_build_log="${report_directory}/${test_name}-validation-build-log.txt"
-mvn ${shared_build_flags} \
-      clean package \
-      -Derror-prone.configuration-args="${error_prone_validation_flags}" \
-      -Dtest='
-        !MetadataGeneratorUtilTest#metadataFilesGenerationAllFiles,
-        !XdocsJavaDocsTest#allCheckSectionJavaDocs' \
-    | tee "${validation_build_log}" \
-  || failure=1
+validation_build_flags='-Dtest=!MetadataGeneratorUtilTest#metadataFilesGenerationAllFiles,!XdocsJavaDocsTest#allCheckSectionJavaDocs'
 
-# Collect the applied changes.
-expected_changes="${integration_test_root}/${test_name}-expected-changes.patch"
-actual_changes="${report_directory}/${test_name}-changes.patch"
-(git diff "${diff_base}"..HEAD | "${grep_command}" -vP '^(diff|index)' || true) > "${actual_changes}"
-
-# Collect the warnings reported by Error Prone Support checks.
-expected_warnings="${integration_test_root}/${test_name}-expected-warnings.txt"
-actual_warnings="${report_directory}/${test_name}-validation-build-warnings.txt"
-("${grep_command}" -oP "(?<=^\\Q[WARNING] ${PWD}/\\E).*" "${validation_build_log}" | "${grep_command}" -P '\] \[' || true) | LC_ALL=C sort > "${actual_warnings}"
-
-# Persist or validate the applied changes and reported warnings.
-if [ -n "${do_sync}" ]; then
-  echo 'Saving changes...'
-  cp "${actual_changes}" "${expected_changes}"
-  cp "${actual_warnings}" "${expected_warnings}"
-else
-  echo 'Inspecting changes...'
-  # XXX: This "diff of diffs" also contains vacuous sections, introduced due to
-  # line offset differences. Try to omit those from the final output.
-  if ! diff -u "${expected_changes}" "${actual_changes}"; then
-    echo 'There are unexpected changes. Inspect the preceding output for details.'
-    failure=1
-  fi
-  echo 'Inspecting emitted warnings...'
-  if ! diff -u "${expected_warnings}" "${actual_warnings}"; then
-    echo 'Diagnostics output changed. Inspect the preceding output for details.'
-    failure=1
-  fi
-fi
-
-if [ -n "${failure:-}" ]; then
+if [ "${#}" -gt 2 ] || ([ "${#}" = 2 ] && [ "${1:---sync}" != '--sync' ]); then
+  >&2 echo "Usage: ${0} [--sync] [<report_directory>]"
   exit 1
 fi
+
+"$(dirname "${0}")/run-integration-test.sh" \
+  "${test_name}" \
+  "${project}" \
+  "${repository}" \
+  "${revision}" \
+  "${additional_build_flags}" \
+  "${additional_source_directories}" \
+  "${patch_error_prone_flags}" \
+  "${validation_error_prone_flags}" \
+  "${validation_build_flags}" \
+  $@

integration-tests/run-integration-test.sh

@@ -0,0 +1,210 @@
+#!/usr/bin/env bash
+
+# Integration test framework for Maven builds.
+#
+# This script is not meant to be invoked manually. Instead it should be invoked
+# through one of the top-level integration test scripts, such as
+# `checkstyle.sh`.
+
+set -e -u -o pipefail
+
+integration_test_root="$(cd "$(dirname -- "${0}")" && pwd)"
+error_prone_support_root="${integration_test_root}/.."
+repos_root="${integration_test_root}/.repos"
+
+if [ "${#}" -lt 9 ] || [ "${#}" -gt 11 ] || ([ "${#}" = 11 ] && [ "${10:---sync}" != '--sync' ]); then
+  >&2 echo "Usage: $(basename "${0}") <test_name> <project> <repository> <revision> <additional_build_flags> <additional_source_directories> <patch_error_prone_flags> <validation_error_prone_flags> <validation_build_flags> [--sync] [<report_directory>]"
+  exit 1
+fi
+
+test_name="${1}"
+project="${2}"
+repository="${3}"
+revision="${4}"
+additional_build_flags="${5}"
+additional_source_directories="${6}"
+patch_error_prone_flags="${7}"
+validation_error_prone_flags="${8}"
+validation_build_flags="${9}"
+do_sync="$([ "${#}" = 9 ] || [ "${10:-}" != '--sync' ] || echo 1)"
+report_directory="$([ "${#}" = 9 ] || ([ -z "${do_sync}" ] && echo "${10}") || ([ "${#}" = 10 ] || echo "${11}"))"
+
+if [ -n "${report_directory}" ]; then
+  mkdir -p "${report_directory}"
+else
+  report_directory="$(mktemp -d)"
+  trap 'rm -rf -- "${report_directory}"' INT TERM HUP EXIT
+fi
+
+case "$(uname -s)" in
+  Linux*)
+    grep_command=grep
+    sed_command=sed
+    ;;
+  Darwin*)
+    grep_command=ggrep
+    sed_command=gsed
+    ;;
+  *)
+    echo "Unsupported distribution $(uname -s) for this script."
+    exit 1
+    ;;
+esac
+
+shared_build_flags="
+  -Perror-prone-compile,error-prone-test-compile
+  -Derror-prone.version=$(
+    mvn -f "${error_prone_support_root}" help:evaluate -Dexpression=version.error-prone -q -DforceStdout
+  )
+  -Derror-prone-support.version=$(
+    mvn -f "${error_prone_support_root}" help:evaluate -Dexpression=project.version -q -DforceStdout
+  )
+  -DadditionalSourceDirectories=${additional_source_directories}
+  ${additional_build_flags}
+  "
+
+# XXX: Configure Renovate to manage the fmt-maven-plugin version declared here.
+# XXX: Once GitHub actions uses Maven 3.9.2+, we can inline this variable with
+# version reference `${fmt.version}`, and `-Dfmt.version=2.21.1` added to
+# `shared_build_flags`.
+format_goal='com.spotify.fmt:fmt-maven-plugin:2.21.1:format'
+
+error_prone_shared_flags='-XepExcludedPaths:(\Q${project.basedir}${file.separator}src${file.separator}\E(it|test|xdocs-examples)\Q${file.separator}resources\E|\Q${project.build.directory}${file.separator}\E).*'
+
+error_prone_patch_flags="${error_prone_shared_flags} -XepPatchLocation:IN_PLACE -XepPatchChecks:$(
+   find "${error_prone_support_root}" \
+      -path "*/META-INF/services/com.google.errorprone.bugpatterns.BugChecker" \
+      -not -path "*/error-prone-experimental/*" \
+      -not -path "*/error-prone-guidelines/*" \
+      -print0 \
+    | xargs -0 "${grep_command}" -hoP '[^.]+$' \
+    | paste -s -d ',' -
+) ${patch_error_prone_flags}"
+
+error_prone_validation_flags="${error_prone_shared_flags} -XepDisableAllChecks $(
+   find "${error_prone_support_root}" \
+      -path "*/META-INF/services/com.google.errorprone.bugpatterns.BugChecker" \
+      -not -path "*/error-prone-experimental/*" \
+      -not -path "*/error-prone-guidelines/*" \
+      -print0 \
+    | xargs -0 "${grep_command}" -hoP '[^.]+$' \
+    | "${sed_command}" -r 's,(.*),-Xep:\1:WARN,' \
+    | paste -s -d ' ' -
+) ${validation_error_prone_flags}"
+
+echo "Shared build flags: ${shared_build_flags}"
+echo "Error Prone patch flags: ${error_prone_patch_flags}"
+echo "Error Prone validation flags: ${error_prone_validation_flags}"
+
+mkdir -p "${repos_root}"
+
+# Make sure that the targeted tag of the project's Git repository is checked
+# out.
+project_root="${repos_root}/${project}"
+if [ ! -d "${project_root}" ]; then
+  # The repository has not yet been cloned; create a shallow clone.
+  git clone --branch "${revision}" --depth 1 "${repository}" "${project_root}"
+else
+  # The repository does already appear to exist. Try to check out the requested
+  # tag if possible, and fetch it otherwise.
+  #
+  # Under certain circumstances this does not cause the relevant tag to be
+  # created, so if necessary we manually create it.
+  git -C "${project_root}" checkout --force "${revision}" 2>/dev/null \
+    || (
+         git -C "${project_root}" fetch --depth 1 "${repository}" "${revision}" \
+           && git -C "${project_root}" checkout --force FETCH_HEAD \
+           && (git -C "${project_root}" tag "${revision}" || true)
+       )
+fi
+
+pushd "${project_root}"
+
+# Make sure that Git is sufficiently configured to enable committing to the
+# project's Git repository.
+git config user.email || git config user.email 'integration-test@example.com'
+git config user.name || git config user.name 'Integration Test'
+
+# Prepare the code for analysis by (a) applying the minimal set of changes
+# required to run Error Prone with Error Prone Support and (b) formatting the
+# code using the same method by which it will be formatted after each
+# compilation round. The initial formatting operation ensures that subsequent
+# modifications can be rendered in a clean manner.
+git clean -fdx
+git apply < "${integration_test_root}/${test_name}-init.patch"
+git commit -m 'dependency: Introduce Error Prone Support' .
+mvn ${shared_build_flags} "${format_goal}"
+git commit -m 'minor: Reformat using Google Java Format' .
+diff_base="$(git rev-parse HEAD)"
+
+# Apply Error Prone Support-suggested changes until a fixed point is reached.
+function apply_patch() {
+  local extra_build_args="${1}"
+
+  mvn ${shared_build_flags} ${extra_build_args} \
+    package "${format_goal}" \
+    -Derror-prone.configuration-args="${error_prone_patch_flags}" \
+    -DskipTests
+
+  if ! git diff --exit-code; then
+    git commit -m 'minor: Apply patches' .
+
+    # Changes were applied, so another compilation round may apply yet more
+    # changes. For performance reasons we perform incremental compilation,
+    # enabled using a misleading flag. (See
+    # https://issues.apache.org/jira/browse/MCOMPILER-209 for details.)
+    apply_patch '-Dmaven.compiler.useIncrementalCompilation=false'
+  elif [ "${extra_build_args}" != 'clean' ]; then
+    # No changes were applied. We'll attempt one more round in which all files
+    # are recompiled, because there are cases in which violations are missed
+    # during incremental compilation.
+    apply_patch 'clean'
+  fi
+}
+apply_patch ''
+
+# Run one more full build and log the output.
+#
+# By also running the tests, we validate that the (majority of) applied changes
+# are behavior preserving.
+validation_build_log="${report_directory}/${test_name}-validation-build-log.txt"
+mvn ${shared_build_flags} \
+      clean package \
+      -Derror-prone.configuration-args="${error_prone_validation_flags}" \
+      ${validation_build_flags} \
+    | tee "${validation_build_log}" \
+  || failure=1
+
+# Collect the applied changes.
+expected_changes="${integration_test_root}/${test_name}-expected-changes.patch"
+actual_changes="${report_directory}/${test_name}-changes.patch"
+(git diff "${diff_base}"..HEAD | "${grep_command}" -vP '^(diff|index)' || true) > "${actual_changes}"
+
+# Collect the warnings reported by Error Prone Support checks.
+expected_warnings="${integration_test_root}/${test_name}-expected-warnings.txt"
+actual_warnings="${report_directory}/${test_name}-validation-build-warnings.txt"
+("${grep_command}" -oP "(?<=^\\Q[WARNING] ${PWD}/\\E).*" "${validation_build_log}" | "${grep_command}" -P '\] \[' || true) | LC_ALL=C sort > "${actual_warnings}"
+
+# Persist or validate the applied changes and reported warnings.
+if [ -n "${do_sync}" ]; then
+  echo 'Saving changes...'
+  cp "${actual_changes}" "${expected_changes}"
+  cp "${actual_warnings}" "${expected_warnings}"
+else
+  echo 'Inspecting changes...'
+  # XXX: This "diff of diffs" also contains vacuous sections, introduced due to
+  # line offset differences. Try to omit those from the final output.
+  if ! diff -u "${expected_changes}" "${actual_changes}"; then
+    echo 'There are unexpected changes. Inspect the preceding output for details.'
+    failure=1
+  fi
+  echo 'Inspecting emitted warnings...'
+  if ! diff -u "${expected_warnings}" "${actual_warnings}"; then
+    echo 'Diagnostics output changed. Inspect the preceding output for details.'
+    failure=1
+  fi
+fi
+
+if [ -n "${failure:-}" ]; then
+  exit 1
+fi

pom.xml

@@ -4,7 +4,7 @@
 
     <groupId>tech.picnic.error-prone-support</groupId>
     <artifactId>error-prone-support</artifactId>
-    <version>0.15.1-SNAPSHOT</version>
+    <version>0.18.1-SNAPSHOT</version>
     <packaging>pom</packaging>
 
     <name>Picnic :: Error Prone Support</name>
@@ -148,7 +148,7 @@
         <groupId.error-prone>com.google.errorprone</groupId.error-prone>
         <!-- The build timestamp is derived from the most recent commit
         timestamp in support of reproducible builds. -->
-        <project.build.outputTimestamp>2024-02-11T13:31:59Z</project.build.outputTimestamp>
+        <project.build.outputTimestamp>2024-08-11T13:05:54Z</project.build.outputTimestamp>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <!-- Glob pattern identifying Refaster rule definition files. These
         Java classes don't contain "regular" code, and thus require special
@@ -205,19 +205,19 @@
         one place. We use these to keep dependencies in sync. Version numbers
         that need to be referenced only once should *not* be listed here. -->
         <version.auto-service>1.1.1</version.auto-service>
-        <version.auto-value>1.10.4</version.auto-value>
+        <version.auto-value>1.11.0</version.auto-value>
         <version.error-prone>${version.error-prone-orig}</version.error-prone>
         <version.error-prone-fork>v${version.error-prone-orig}-picnic-1</version.error-prone-fork>
-        <version.error-prone-orig>2.24.1</version.error-prone-orig>
-        <version.error-prone-slf4j>0.1.22</version.error-prone-slf4j>
+        <version.error-prone-orig>2.32.0</version.error-prone-orig>
+        <version.error-prone-slf4j>0.1.28</version.error-prone-slf4j>
         <version.guava-beta-checker>1.0</version.guava-beta-checker>
         <version.jdk>17</version.jdk>
-        <version.maven>3.9.5</version.maven>
-        <version.mockito>5.10.0</version.mockito>
+        <version.maven>3.9.9</version.maven>
+        <version.mockito>5.13.0</version.mockito>
         <version.nopen-checker>1.0.1</version.nopen-checker>
-        <version.nullaway>0.10.23</version.nullaway>
+        <version.nullaway>0.11.2</version.nullaway>
         <version.pitest-git>1.1.4</version.pitest-git>
-        <version.rewrite-templating>1.5.0</version.rewrite-templating>
+        <version.rewrite-templating>1.14.1</version.rewrite-templating>
         <version.surefire>3.2.3</version.surefire>
     </properties>
 
@@ -296,10 +296,15 @@
             <dependency>
                 <groupId>com.fasterxml.jackson</groupId>
                 <artifactId>jackson-bom</artifactId>
-                <version>2.16.1</version>
+                <version>2.17.2</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
+            <dependency>
+                <groupId>com.github.ben-manes.caffeine</groupId>
+                <artifactId>caffeine</artifactId>
+                <version>3.1.8</version>
+            </dependency>
             <dependency>
                 <groupId>com.google.auto</groupId>
                 <artifactId>auto-common</artifactId>
@@ -328,7 +333,7 @@
             <dependency>
                 <groupId>com.google.googlejavaformat</groupId>
                 <artifactId>google-java-format</artifactId>
-                <version>1.19.2</version>
+                <version>1.23.0</version>
             </dependency>
             <dependency>
                 <groupId>com.google.guava</groupId>
@@ -338,14 +343,14 @@
             <dependency>
                 <groupId>com.google.guava</groupId>
                 <artifactId>guava-bom</artifactId>
-                <version>33.0.0-jre</version>
+                <version>33.3.0-jre</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
             <dependency>
                 <groupId>com.google.truth</groupId>
                 <artifactId>truth</artifactId>
-                <version>1.4.1</version>
+                <version>1.4.4</version>
             </dependency>
             <dependency>
                 <groupId>com.jakewharton.nopen</groupId>
@@ -357,10 +362,15 @@
                 <artifactId>nullaway</artifactId>
                 <version>${version.nullaway}</version>
             </dependency>
+            <dependency>
+                <groupId>io.github.java-diff-utils</groupId>
+                <artifactId>java-diff-utils</artifactId>
+                <version>4.12</version>
+            </dependency>
             <dependency>
                 <groupId>io.projectreactor</groupId>
                 <artifactId>reactor-bom</artifactId>
-                <version>2023.0.3</version>
+                <version>2023.0.10</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
@@ -372,17 +382,22 @@
             <dependency>
                 <groupId>io.swagger</groupId>
                 <artifactId>swagger-annotations</artifactId>
-                <version>1.6.13</version>
+                <version>1.6.14</version>
             </dependency>
             <dependency>
                 <groupId>io.swagger.core.v3</groupId>
                 <artifactId>swagger-annotations</artifactId>
-                <version>2.2.20</version>
+                <version>2.2.23</version>
             </dependency>
             <dependency>
                 <groupId>jakarta.servlet</groupId>
                 <artifactId>jakarta.servlet-api</artifactId>
-                <version>6.0.0</version>
+                <version>6.1.0</version>
+            </dependency>
+            <dependency>
+                <groupId>javax.annotation</groupId>
+                <artifactId>javax.annotation-api</artifactId>
+                <version>1.3.2</version>
             </dependency>
             <dependency>
                 <groupId>javax.inject</groupId>
@@ -407,7 +422,7 @@
             <dependency>
                 <groupId>net.bytebuddy</groupId>
                 <artifactId>byte-buddy</artifactId>
-                <version>1.14.12</version>
+                <version>1.15.1</version>
             </dependency>
             <!-- Specified so that Renovate will file Maven upgrade PRs, which
             subsequently will cause `maven-enforcer-plugin` to require that
@@ -420,24 +435,24 @@
             <dependency>
                 <groupId>org.aspectj</groupId>
                 <artifactId>aspectjweaver</artifactId>
-                <version>1.9.21.1</version>
+                <version>1.9.22.1</version>
             </dependency>
             <dependency>
                 <groupId>org.assertj</groupId>
                 <artifactId>assertj-bom</artifactId>
-                <version>3.25.3</version>
+                <version>3.26.3</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
             <dependency>
                 <groupId>org.checkerframework</groupId>
                 <artifactId>checker-qual</artifactId>
-                <version>3.42.0</version>
+                <version>3.47.0</version>
             </dependency>
             <dependency>
                 <groupId>org.hamcrest</groupId>
                 <artifactId>hamcrest-core</artifactId>
-                <version>2.2</version>
+                <version>3.0</version>
             </dependency>
             <dependency>
                 <groupId>org.immutables</groupId>
@@ -447,12 +462,12 @@
             <dependency>
                 <groupId>org.jspecify</groupId>
                 <artifactId>jspecify</artifactId>
-                <version>0.3.0</version>
+                <version>1.0.0</version>
             </dependency>
             <dependency>
                 <groupId>org.junit</groupId>
                 <artifactId>junit-bom</artifactId>
-                <version>5.10.2</version>
+                <version>5.11.0</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
@@ -466,7 +481,7 @@
             <dependency>
                 <groupId>org.mongodb</groupId>
                 <artifactId>mongodb-driver-core</artifactId>
-                <version>4.11.1</version>
+                <version>5.1.4</version>
             </dependency>
             <dependency>
                 <groupId>org.openrewrite</groupId>
@@ -476,40 +491,40 @@
             <dependency>
                 <groupId>org.openrewrite.recipe</groupId>
                 <artifactId>rewrite-recipe-bom</artifactId>
-                <version>2.6.4</version>
+                <version>2.18.0</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
             <dependency>
                 <groupId>org.slf4j</groupId>
                 <artifactId>slf4j-bom</artifactId>
-                <version>2.0.12</version>
+                <version>2.0.16</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
             <dependency>
                 <groupId>org.springframework</groupId>
                 <artifactId>spring-framework-bom</artifactId>
-                <version>6.1.4</version>
+                <version>6.1.12</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
             <dependency>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-test</artifactId>
-                <version>3.2.2</version>
+                <version>3.3.3</version>
             </dependency>
             <dependency>
                 <groupId>org.springframework.security</groupId>
                 <artifactId>spring-security-bom</artifactId>
-                <version>6.2.2</version>
+                <version>6.3.3</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
             <dependency>
                 <groupId>org.testng</groupId>
                 <artifactId>testng</artifactId>
-                <version>7.9.0</version>
+                <version>7.10.2</version>
             </dependency>
         </dependencies>
     </dependencyManagement>
@@ -520,7 +535,7 @@
                 <plugin>
                     <groupId>com.github.ekryd.sortpom</groupId>
                     <artifactId>sortpom-maven-plugin</artifactId>
-                    <version>3.3.0</version>
+                    <version>4.0.0</version>
                     <configuration>
                         <createBackupFile>false</createBackupFile>
                         <encoding>${project.build.sourceEncoding}</encoding>
@@ -557,7 +572,7 @@
                 <plugin>
                     <groupId>com.spotify.fmt</groupId>
                     <artifactId>fmt-maven-plugin</artifactId>
-                    <version>2.22.1</version>
+                    <version>2.24</version>
                     <configuration>
                         <additionalSourceDirectories>
                             <additionalSourceDirectory>${basedir}/src/test/resources</additionalSourceDirectory>
@@ -577,7 +592,7 @@
                 <plugin>
                     <groupId>de.thetaphi</groupId>
                     <artifactId>forbiddenapis</artifactId>
-                    <version>3.6</version>
+                    <version>3.7</version>
                     <configuration>
                         <bundledSignatures>
                             <bundledSignature>jdk-internal</bundledSignature>
@@ -624,7 +639,7 @@
                 <plugin>
                     <groupId>io.github.git-commit-id</groupId>
                     <artifactId>git-commit-id-maven-plugin</artifactId>
-                    <version>7.0.0</version>
+                    <version>9.0.1</version>
                     <configuration>
                         <injectAllReactorProjects>true</injectAllReactorProjects>
                         <runOnlyOnce>true</runOnlyOnce>
@@ -643,7 +658,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-checkstyle-plugin</artifactId>
-                    <version>3.3.1</version>
+                    <version>3.5.0</version>
                     <configuration>
                         <checkstyleRules>
                             <!-- We only enable rules that are not enforced by
@@ -679,6 +694,7 @@
                                         <property name="allowNonPrintableEscapes" value="true" />
                                     </module>
                                     <module name="AvoidNoArgumentSuperConstructorCall" />
+                                    <module name="ConstructorsDeclarationGrouping" />
                                     <module name="DeclarationOrder">
                                         <!-- We don't enforce sorting fields by
                                         their visibility modifier, for two
@@ -891,7 +907,7 @@
                         <dependency>
                             <groupId>com.puppycrawl.tools</groupId>
                             <artifactId>checkstyle</artifactId>
-                            <version>10.13.0</version>
+                            <version>10.18.1</version>
                         </dependency>
                         <dependency>
                             <groupId>io.spring.nohttp</groupId>
@@ -911,12 +927,12 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-clean-plugin</artifactId>
-                    <version>3.3.2</version>
+                    <version>3.4.0</version>
                 </plugin>
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-compiler-plugin</artifactId>
-                    <version>3.12.1</version>
+                    <version>3.13.0</version>
                     <configuration>
                         <annotationProcessorPaths>
                             <!-- XXX: Inline and drop the version
@@ -959,11 +975,43 @@
                         https://issues.apache.org/jira/browse/MCOMPILER-209. -->
                         <useIncrementalCompilation>false</useIncrementalCompilation>
                     </configuration>
+                    <executions>
+                        <!-- OpenRewrite recipe sources, generated by the
+                        `rewrite-templating` annotation processor and
+                        identified as classes whose name ends in `Recipes`, are
+                        compiled to target Java 8 for compatibility with the
+                        wider OpenRewrite ecosystem. The `maven-jar-plugin` is
+                        configured to package these files into a separate JAR. -->
+                        <execution>
+                            <id>compile-recipes</id>
+                            <goals>
+                                <goal>compile</goal>
+                            </goals>
+                            <configuration>
+                                <compilerArgs combine.self="override">
+                                    <!-- When Java 8 is targeted we can't use
+                                    the `add-exports` flag. And since this goal
+                                    only recompiles already-compiled code,
+                                    static analysis is irrelevant. As such we
+                                    clear all compiler arguments, and only
+                                    suppress source/target/bootstrap classpath
+                                    warnings. -->
+                                    <arg>-Xlint:-options</arg>
+                                </compilerArgs>
+                                <source>8</source>
+                                <target>8</target>
+                                <includes>
+                                    <include>**/*Recipes.java</include>
+                                </includes>
+                                <outputDirectory>${project.build.directory}/openrewrite-recipes</outputDirectory>
+                            </configuration>
+                        </execution>
+                    </executions>
                 </plugin>
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-dependency-plugin</artifactId>
-                    <version>3.6.1</version>
+                    <version>3.8.0</version>
                     <configuration>
                         <!-- XXX: Drop `ignoreAllNonTestScoped` once
                         https://issues.apache.org/jira/browse/MNG-6058 is
@@ -978,7 +1026,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-deploy-plugin</artifactId>
-                    <version>3.1.1</version>
+                    <version>3.1.3</version>
                     <configuration>
                         <retryFailedDeploymentCount>3</retryFailedDeploymentCount>
                     </configuration>
@@ -986,7 +1034,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-enforcer-plugin</artifactId>
-                    <version>3.4.1</version>
+                    <version>3.5.0</version>
                     <configuration>
                         <fail>false</fail>
                         <rules>
@@ -1041,6 +1089,9 @@
                             <requireJavaVersion>
                                 <version>${version.jdk}</version>
                             </requireJavaVersion>
+                            <requireMatchingCoordinates>
+                                <moduleNameMustMatchArtifactId>true</moduleNameMustMatchArtifactId>
+                            </requireMatchingCoordinates>
                             <requireMavenVersion>
                                 <version>${version.maven}</version>
                             </requireMavenVersion>
@@ -1053,7 +1104,7 @@
                         <dependency>
                             <groupId>org.codehaus.mojo</groupId>
                             <artifactId>extra-enforcer-rules</artifactId>
-                            <version>1.7.0</version>
+                            <version>1.8.0</version>
                         </dependency>
                     </dependencies>
                     <executions>
@@ -1068,7 +1119,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-gpg-plugin</artifactId>
-                    <version>3.1.0</version>
+                    <version>3.2.5</version>
                     <executions>
                         <execution>
                             <id>sign-artifacts</id>
@@ -1081,12 +1132,12 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-install-plugin</artifactId>
-                    <version>3.1.1</version>
+                    <version>3.1.3</version>
                 </plugin>
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-jar-plugin</artifactId>
-                    <version>3.3.0</version>
+                    <version>3.4.2</version>
                     <configuration>
                         <skipIfEmpty>true</skipIfEmpty>
                         <archive>
@@ -1103,6 +1154,39 @@
                         </archive>
                     </configuration>
                     <executions>
+                        <execution>
+                            <id>default-jar</id>
+                            <goals>
+                                <goal>jar</goal>
+                            </goals>
+                            <configuration>
+                                <!-- These Java 17 bytecode classes are omitted
+                                from the default JAR, as instead we produce a
+                                separate artifact with Java 8 bytecode variants. -->
+                                <excludes>
+                                    <excludes>**/*Recipe$*.class</excludes>
+                                    <excludes>**/*Recipe.class</excludes>
+                                    <excludes>**/*Recipes.class</excludes>
+                                </excludes>
+                            </configuration>
+                        </execution>
+                        <execution>
+                            <!-- Creates a custom JAR with Java 8-compatible
+                            OpenRewrite recipe classes. -->
+                            <id>create-openrewrite-recipes-jar</id>
+                            <goals>
+                                <goal>jar</goal>
+                            </goals>
+                            <configuration>
+                                <classesDirectory>${project.build.directory}/openrewrite-recipes</classesDirectory>
+                                <classifier>recipes</classifier>
+                                <includes>
+                                    <includes>**/*Recipe$*.class</includes>
+                                    <includes>**/*Recipe.class</includes>
+                                    <includes>**/*Recipes.class</includes>
+                                </includes>
+                            </configuration>
+                        </execution>
                         <execution>
                             <id>create-test-jar</id>
                             <goals>
@@ -1114,7 +1198,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-javadoc-plugin</artifactId>
-                    <version>3.6.3</version>
+                    <version>3.10.0</version>
                     <configuration>
                         <additionalJOptions>
                             <additionalJOption>--add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED</additionalJOption>
@@ -1143,7 +1227,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-release-plugin</artifactId>
-                    <version>3.0.1</version>
+                    <version>3.1.1</version>
                     <configuration>
                         <autoVersionSubmodules>true</autoVersionSubmodules>
                         <preparationProfiles>release</preparationProfiles>
@@ -1170,7 +1254,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-source-plugin</artifactId>
-                    <version>3.3.0</version>
+                    <version>3.3.1</version>
                     <executions>
                         <execution>
                             <id>generate-source-jar</id>
@@ -1184,7 +1268,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-surefire-plugin</artifactId>
-                    <version>3.2.5</version>
+                    <version>3.5.0</version>
                     <configuration>
                         <includes>
                             <include>**/*Test.java</include>
@@ -1200,7 +1284,7 @@
                 <plugin>
                     <groupId>org.codehaus.mojo</groupId>
                     <artifactId>build-helper-maven-plugin</artifactId>
-                    <version>3.5.0</version>
+                    <version>3.6.0</version>
                 </plugin>
                 <plugin>
                     <groupId>org.codehaus.mojo</groupId>
@@ -1296,6 +1380,7 @@
                                 <!-- -->
                                 GPL-2.0-with-classpath-exception
                                 | CDDL/GPLv2+CE
+                                | CDDL + GPLv2 with classpath exception
                                 | GNU General Public License, version 2 (GPL2), with the classpath exception
                                 | GNU General Public License, version 2, with the Classpath Exception
                                 | GPL2 w/ CPE
@@ -1330,7 +1415,7 @@
                 <plugin>
                     <groupId>org.codehaus.mojo</groupId>
                     <artifactId>tidy-maven-plugin</artifactId>
-                    <version>1.2.0</version>
+                    <version>1.3.0</version>
                     <executions>
                         <execution>
                             <id>check-pom</id>
@@ -1343,7 +1428,7 @@
                 <plugin>
                     <groupId>org.codehaus.mojo</groupId>
                     <artifactId>versions-maven-plugin</artifactId>
-                    <version>2.16.2</version>
+                    <version>2.17.1</version>
                     <configuration>
                         <updateBuildOutputTimestampPolicy>never</updateBuildOutputTimestampPolicy>
                     </configuration>
@@ -1351,7 +1436,7 @@
                 <plugin>
                     <groupId>org.gaul</groupId>
                     <artifactId>modernizer-maven-plugin</artifactId>
-                    <version>2.7.0</version>
+                    <version>2.9.0</version>
                     <configuration>
                         <exclusionPatterns>
                             <!-- The plugin suggests replacing usages of
@@ -1382,7 +1467,7 @@
                 <plugin>
                     <groupId>org.jacoco</groupId>
                     <artifactId>jacoco-maven-plugin</artifactId>
-                    <version>0.8.11</version>
+                    <version>0.8.12</version>
                     <configuration>
                         <excludes>
                             <!-- Refaster rules are tested using a custom method
@@ -1394,7 +1479,7 @@
                 <plugin>
                     <groupId>org.kordamp.maven</groupId>
                     <artifactId>pomchecker-maven-plugin</artifactId>
-                    <version>1.10.0</version>
+                    <version>1.13.0</version>
                     <configuration>
                         <failOnError>false</failOnError>
                         <release>false</release>
@@ -1412,7 +1497,7 @@
                 <plugin>
                     <groupId>org.pitest</groupId>
                     <artifactId>pitest-maven</artifactId>
-                    <version>1.15.8</version>
+                    <version>1.16.1</version>
                     <configuration>
                         <excludedClasses>
                             <!-- AutoValue generated classes. -->
@@ -1466,7 +1551,7 @@
                 <plugin>
                     <groupId>org.sonarsource.scanner.maven</groupId>
                     <artifactId>sonar-maven-plugin</artifactId>
-                    <version>3.10.0.2594</version>
+                    <version>4.0.0.4121</version>
                 </plugin>
             </plugins>
         </pluginManagement>
@@ -1743,6 +1828,11 @@
                         <groupId>org.apache.maven.plugins</groupId>
                         <artifactId>maven-enforcer-plugin</artifactId>
                     </plugin>
+                    <plugin>
+                        <groupId>org.codehaus.mojo</groupId>
+                        <artifactId>exec-maven-plugin</artifactId>
+                        <version>3.4.1</version>
+                    </plugin>
                     <plugin>
                         <groupId>org.codehaus.mojo</groupId>
                         <artifactId>license-maven-plugin</artifactId>

refaster-compiler/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.15.1-SNAPSHOT</version>
+        <version>0.18.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>refaster-compiler</artifactId>

refaster-compiler/src/main/java/tech/picnic/errorprone/refaster/plugin/RefasterRuleCompilerTaskListener.java

@@ -21,7 +21,6 @@ import com.sun.tools.javac.code.Symbol.ClassSymbol;
 import com.sun.tools.javac.code.Symbol.PackageSymbol;
 import com.sun.tools.javac.main.JavaCompiler;
 import com.sun.tools.javac.util.Context;
-import com.sun.tools.javac.util.Name;
 import java.io.IOException;
 import java.io.ObjectOutput;
 import java.io.ObjectOutputStream;
@@ -112,7 +111,7 @@ final class RefasterRuleCompilerTaskListener implements TaskListener {
             return (sym != null
                     && sym.getQualifiedName()
                         .contentEquals(BeforeTemplate.class.getCanonicalName()))
-                || super.visitAnnotation(node, unused);
+                || super.visitAnnotation(node, null);
           }
 
           @Override
@@ -137,10 +136,10 @@ final class RefasterRuleCompilerTaskListener implements TaskListener {
     return enclosingPackage == null ? "" : enclosingPackage.toString();
   }
 
-  private static CharSequence toSimpleFlatName(ClassSymbol symbol) {
-    Name flatName = symbol.flatName();
+  private static String toSimpleFlatName(ClassSymbol symbol) {
+    String flatName = symbol.flatName().toString();
     int lastDot = flatName.lastIndexOf((byte) '.');
-    return lastDot < 0 ? flatName : flatName.subSequence(lastDot + 1, flatName.length());
+    return lastDot < 0 ? flatName : flatName.substring(lastDot + 1);
   }
 
   private static void outputCodeTransformer(CodeTransformer codeTransformer, FileObject target)

refaster-runner/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.15.1-SNAPSHOT</version>
+        <version>0.18.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>refaster-runner</artifactId>
@@ -58,6 +58,11 @@
             <artifactId>guava</artifactId>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>javax.annotation</groupId>
+            <artifactId>javax.annotation-api</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>javax.inject</groupId>
             <artifactId>javax.inject</artifactId>

refaster-runner/src/main/java/tech/picnic/errorprone/refaster/runner/Refaster.java

@@ -166,7 +166,7 @@ public final class Refaster extends BugChecker implements CompilationUnitTreeMat
             "Refaster Rule",
             description.getLink(),
             String.join(": ", description.checkName, description.getRawMessage()))
-        .overrideSeverity(severityOverride.orElse(description.severity()))
+        .overrideSeverity(severityOverride.orElseGet(description::severity))
         .addAllFixes(description.fixes)
         .build();
   }

refaster-support/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.15.1-SNAPSHOT</version>
+        <version>0.18.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>refaster-support</artifactId>

refaster-support/src/main/java/tech/picnic/errorprone/refaster/matchers/RequiresComputation.java

@@ -2,6 +2,7 @@ package tech.picnic.errorprone.refaster.matchers;
 
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.matchers.Matcher;
+import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.ArrayAccessTree;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.IdentifierTree;
@@ -9,34 +10,19 @@ import com.sun.source.tree.LambdaExpressionTree;
 import com.sun.source.tree.LiteralTree;
 import com.sun.source.tree.MemberReferenceTree;
 import com.sun.source.tree.MemberSelectTree;
-import com.sun.source.tree.MethodInvocationTree;
 import com.sun.source.tree.ParenthesizedTree;
 import com.sun.source.tree.TypeCastTree;
 import com.sun.source.tree.UnaryTree;
 
-/** A matcher of expressions that likely require little to no computation. */
-public final class IsLikelyTrivialComputation implements Matcher<ExpressionTree> {
+/** A matcher of expressions that may a non-trivial amount of computation. */
+public final class RequiresComputation implements Matcher<ExpressionTree> {
   private static final long serialVersionUID = 1L;
 
-  /** Instantiates a new {@link IsLikelyTrivialComputation} instance. */
-  public IsLikelyTrivialComputation() {}
+  /** Instantiates a new {@link RequiresComputation} instance. */
+  public RequiresComputation() {}
 
   @Override
   public boolean matches(ExpressionTree expressionTree, VisitorState state) {
-    if (expressionTree instanceof MethodInvocationTree methodInvocation) {
-      // XXX: Method invocations are generally *not* trivial computations, but we make an exception
-      // for nullary method invocations on the result of a trivial computation. This exception
-      // allows this `Matcher` to by the `OptionalOrElseGet` Refaster rule, such that it does not
-      // suggest the introduction of lambda expressions that are better expressed as method
-      // references. Once the `MethodReferenceUsage` bug checker is production-ready, this exception
-      // should be removed. (But at that point, instead defining a `RequiresComputation` matcher may
-      // be more appropriate.)
-      if (methodInvocation.getArguments().isEmpty()
-          && matches(methodInvocation.getMethodSelect())) {
-        return true;
-      }
-    }
-
     return matches(expressionTree);
   }
 
@@ -44,11 +30,11 @@ public final class IsLikelyTrivialComputation implements Matcher<ExpressionTree>
   // Depending on feedback such trees may be matched in the future.
   private static boolean matches(ExpressionTree expressionTree) {
     if (expressionTree instanceof ArrayAccessTree arrayAccess) {
-      return matches(arrayAccess.getExpression()) && matches(arrayAccess.getIndex());
+      return matches(arrayAccess.getExpression()) || matches(arrayAccess.getIndex());
     }
 
     if (expressionTree instanceof LiteralTree) {
-      return true;
+      return false;
     }
 
     if (expressionTree instanceof LambdaExpressionTree) {
@@ -56,11 +42,14 @@ public final class IsLikelyTrivialComputation implements Matcher<ExpressionTree>
        * Lambda expressions encapsulate computations, but their definition does not involve
        * significant computation.
        */
-      return true;
+      return false;
     }
 
     if (expressionTree instanceof IdentifierTree) {
-      return true;
+      // XXX: Generally identifiers don't by themselves represent a computation, though they may be
+      // a stand-in for one if they are a Refaster template method argument. Can we identify such
+      // cases, also when the `Matcher` is invoked by Refaster?
+      return false;
     }
 
     if (expressionTree instanceof MemberReferenceTree memberReference) {
@@ -80,11 +69,11 @@ public final class IsLikelyTrivialComputation implements Matcher<ExpressionTree>
     }
 
     if (expressionTree instanceof UnaryTree unary) {
-      // XXX: Arguably side-effectful options such as pre- and post-increment and -decrement are not
-      // trivial.
+      // XXX: Arguably side-effectful options such as pre- and post-increment and -decrement
+      // represent non-trivial computations.
       return matches(unary.getExpression());
     }
 
-    return false;
+    return ASTHelpers.constValue(expressionTree) == null;
   }
 }

refaster-support/src/test/java/tech/picnic/errorprone/refaster/matchers/RequiresComputationTest.java

@@ -8,54 +8,69 @@ import com.google.errorprone.bugpatterns.BugChecker;
 import com.sun.source.tree.ReturnTree;
 import org.junit.jupiter.api.Test;
 
-final class IsLikelyTrivialComputationTest {
+final class RequiresComputationTest {
   @Test
   void matches() {
     CompilationTestHelper.newInstance(MatcherTestChecker.class, getClass())
         .addSourceLines(
             "A.java",
+            "import java.io.OutputStream;",
+            "import java.util.Comparator;",
             "import java.util.function.Predicate;",
             "",
             "class A {",
-            "  String negative1() {",
-            "    return String.valueOf(1);",
+            "  int negative1() {",
+            "    int[] arr = new int[0];",
+            "    return arr[0];",
             "  }",
             "",
             "  String negative2() {",
-            "    return toString().toString();",
+            "    return null;",
             "  }",
             "",
-            "  String negative3() {",
-            "    return \"foo\" + toString();",
+            "  boolean negative3() {",
+            "    return false;",
             "  }",
             "",
-            "  byte negative4() {",
-            "    return \"foo\".getBytes()[0];",
+            "  int negative4() {",
+            "    return 0;",
             "  }",
             "",
-            "  int negative5() {",
-            "    int[] arr = new int[0];",
-            "    return arr[hashCode()];",
+            "  String negative5() {",
+            "    return \"foo\" + \"bar\";",
             "  }",
             "",
-            "  int negative6() {",
-            "    return 1 * 2;",
+            "  Predicate<String> negative6() {",
+            "    return v -> \"foo\".equals(v);",
             "  }",
             "",
-            "  Predicate<String> negative7() {",
-            "    return toString()::equals;",
+            "  A negative7() {",
+            "    return this;",
             "  }",
             "",
-            "  String negative8() {",
-            "    return (toString());",
+            "  Predicate<String> negative8() {",
+            "    return \"foo\"::equals;",
             "  }",
             "",
-            "  Object negative9() {",
-            "    return (Object) toString();",
+            "  OutputStream negative9() {",
+            "    return System.out;",
             "  }",
             "",
-            "  int negative10() {",
-            "    return -hashCode();",
+            "  A negative10() {",
+            "    return (this);",
+            "  }",
+            "",
+            "  Object negative11() {",
+            "    return (Object) this;",
+            "  }",
+            "",
+            "  boolean negative12() {",
+            "    boolean[] arr = new boolean[0];",
+            "    return !arr[0];",
+            "  }",
+            "",
+            "  String negative13() {",
+            "    return \"foo\" + 0;",
             "  }",
             "",
             "  String positive1() {",
@@ -68,68 +83,63 @@ final class IsLikelyTrivialComputationTest {
             "    return this.toString();",
             "  }",
             "",
-            "  int positive3() {",
-            "    int[] arr = new int[0];",
+            "  String positive3() {",
             "    // BUG: Diagnostic contains:",
-            "    return arr[0];",
+            "    return String.valueOf(1);",
             "  }",
             "",
             "  String positive4() {",
             "    // BUG: Diagnostic contains:",
-            "    return null;",
+            "    return toString().toString();",
             "  }",
             "",
-            "  boolean positive5() {",
+            "  String positive5() {",
             "    // BUG: Diagnostic contains:",
-            "    return false;",
+            "    return \"foo\" + toString();",
             "  }",
             "",
-            "  int positive6() {",
+            "  byte positive6() {",
             "    // BUG: Diagnostic contains:",
-            "    return 0;",
+            "    return \"foo\".getBytes()[0];",
             "  }",
             "",
-            "  String positive7() {",
+            "  int positive7() {",
+            "    int[] arr = new int[0];",
             "    // BUG: Diagnostic contains:",
-            "    return \"foo\" + \"bar\";",
+            "    return arr[hashCode()];",
             "  }",
             "",
             "  Predicate<String> positive8() {",
             "    // BUG: Diagnostic contains:",
-            "    return v -> \"foo\".equals(v);",
+            "    return toString()::equals;",
             "  }",
             "",
-            "  A positive9() {",
+            "  Comparator<String> positive9() {",
             "    // BUG: Diagnostic contains:",
-            "    return this;",
+            "    return toString().CASE_INSENSITIVE_ORDER;",
             "  }",
             "",
-            "  Predicate<String> positive10() {",
+            "  String positive10() {",
             "    // BUG: Diagnostic contains:",
-            "    return \"foo\"::equals;",
+            "    return (toString());",
             "  }",
             "",
-            "  A positive11() {",
+            "  Object positive11() {",
             "    // BUG: Diagnostic contains:",
-            "    return (this);",
+            "    return (Object) toString();",
             "  }",
             "",
-            "  Object positive12() {",
+            "  int positive12() {",
             "    // BUG: Diagnostic contains:",
-            "    return (Object) this;",
-            "  }",
-            "",
-            "  boolean positive13() {",
-            "    // BUG: Diagnostic contains:",
-            "    return !false;",
+            "    return -hashCode();",
             "  }",
             "}")
         .doTest();
   }
 
-  /** A {@link BugChecker} that simply delegates to {@link IsLikelyTrivialComputation}. */
+  /** A {@link BugChecker} that simply delegates to {@link RequiresComputation}. */
   @BugPattern(
-      summary = "Flags return statement expressions matched by `IsLikelyTrivialComputation`",
+      summary = "Flags return statement expressions matched by `RequiresComputation`",
       severity = ERROR)
   public static final class MatcherTestChecker extends AbstractMatcherTestChecker {
     private static final long serialVersionUID = 1L;
@@ -141,7 +151,7 @@ final class IsLikelyTrivialComputationTest {
       super(
           (expressionTree, state) ->
               state.getPath().getParentPath().getLeaf() instanceof ReturnTree
-                  && new IsLikelyTrivialComputation().matches(expressionTree, state));
+                  && new RequiresComputation().matches(expressionTree, state));
     }
   }
 }

refaster-test-support/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.15.1-SNAPSHOT</version>
+        <version>0.18.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>refaster-test-support</artifactId>
@@ -50,6 +50,11 @@
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
         </dependency>
+        <dependency>
+            <groupId>javax.annotation</groupId>
+            <artifactId>javax.annotation-api</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>javax.inject</groupId>
             <artifactId>javax.inject</artifactId>

refaster-test-support/src/main/java/tech/picnic/errorprone/refaster/test/RefasterRuleCollection.java

@@ -61,6 +61,9 @@ import tech.picnic.errorprone.refaster.runner.Refaster;
 // XXX: This check currently only validates that one `Refaster.anyOf` branch in one
 // `@BeforeTemplate` method is covered by a test. Review how we can make sure that _all_
 // `@BeforeTemplate` methods and `Refaster.anyOf` branches are covered.
+// XXX: Look into replacing this setup with another that allows test cases to be co-located
+// with/nested within the rules. This way any rule change only requires modifications in a single
+// place, rather than in three.
 @BugPattern(summary = "Exercises a Refaster rule collection", linkType = NONE, severity = ERROR)
 @SuppressWarnings("java:S2160" /* Super class equality definition suffices. */)
 public final class RefasterRuleCollection extends BugChecker implements CompilationUnitTreeMatcher {
@@ -319,7 +322,7 @@ public final class RefasterRuleCollection extends BugChecker implements Compilat
       return indexedMatches.subRangeMap(Range.closedOpen(startPosition, endPosition));
     }
 
-    private ImmutableListMultimap<Long, String> getUnexpectedMatchesByLineNumber(
+    private static ImmutableListMultimap<Long, String> getUnexpectedMatchesByLineNumber(
         ImmutableRangeMap<Integer, String> matches, String ruleUnderTest, VisitorState state) {
       LineMap lineMap = state.getPath().getCompilationUnit().getLineMap();
       return matches.asMapOfRanges().entrySet().stream()

website/.gitignore

@@ -1,12 +1,13 @@
 # Generated by Bundler and Jekyll.
 .bundle/
-Gemfile.lock
 .jekyll-cache/
 .jekyll-metadata
 .sass-cache/
 _site/
 vendor/
 
-# Generated by `../generate-docs.sh`.
-*.bak
+# XXX: Update generator name when it's renamed.
+# Generated by `JekyllCollectionGenerator`.
 index.md
+_bugpatterns/
+_refasterrules/

website/Gemfile

@@ -1,8 +1,15 @@
 ruby File.read(".ruby-version").strip
 
 source "https://rubygems.org"
-gem "html-proofer", "4.4.1"
-gem "jekyll", "4.2.2"
-gem "jekyll-sitemap", "1.4"
-gem "just-the-docs", "0.4.0.rc2"
-gem "webrick", "1.7"
+
+group :jekyll_site_dependencies do
+  gem "jekyll", "4.3.2"
+  gem "jekyll-sitemap", "1.4.0"
+  gem "just-the-docs", "0.6.2"
+  gem "rake", "13.0.6"
+  gem "webrick", "1.8.1"
+end
+
+group :website_validation_dependencies do
+  gem "html-proofer", "5.0.8"
+end

website/Gemfile.lock

@@ -0,0 +1,133 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    Ascii85 (1.1.0)
+    addressable (2.8.5)
+      public_suffix (>= 2.0.2, < 6.0)
+    afm (0.2.2)
+    async (2.6.4)
+      console (~> 1.10)
+      fiber-annotation
+      io-event (~> 1.1)
+      timers (~> 4.1)
+    colorator (1.1.0)
+    concurrent-ruby (1.2.2)
+    console (1.23.2)
+      fiber-annotation
+      fiber-local
+    em-websocket (0.5.3)
+      eventmachine (>= 0.12.9)
+      http_parser.rb (~> 0)
+    ethon (0.16.0)
+      ffi (>= 1.15.0)
+    eventmachine (1.2.7)
+    ffi (1.16.3)
+    fiber-annotation (0.2.0)
+    fiber-local (1.0.0)
+    forwardable-extended (2.6.0)
+    google-protobuf (3.24.4-x86_64-linux)
+    hashery (2.1.2)
+    html-proofer (5.0.8)
+      addressable (~> 2.3)
+      async (~> 2.1)
+      nokogiri (~> 1.13)
+      pdf-reader (~> 2.11)
+      rainbow (~> 3.0)
+      typhoeus (~> 1.3)
+      yell (~> 2.0)
+      zeitwerk (~> 2.5)
+    http_parser.rb (0.8.0)
+    i18n (1.14.1)
+      concurrent-ruby (~> 1.0)
+    io-event (1.3.2)
+    jekyll (4.3.2)
+      addressable (~> 2.4)
+      colorator (~> 1.0)
+      em-websocket (~> 0.5)
+      i18n (~> 1.0)
+      jekyll-sass-converter (>= 2.0, < 4.0)
+      jekyll-watch (~> 2.0)
+      kramdown (~> 2.3, >= 2.3.1)
+      kramdown-parser-gfm (~> 1.0)
+      liquid (~> 4.0)
+      mercenary (>= 0.3.6, < 0.5)
+      pathutil (~> 0.9)
+      rouge (>= 3.0, < 5.0)
+      safe_yaml (~> 1.0)
+      terminal-table (>= 1.8, < 4.0)
+      webrick (~> 1.7)
+    jekyll-include-cache (0.2.1)
+      jekyll (>= 3.7, < 5.0)
+    jekyll-sass-converter (3.0.0)
+      sass-embedded (~> 1.54)
+    jekyll-seo-tag (2.8.0)
+      jekyll (>= 3.8, < 5.0)
+    jekyll-sitemap (1.4.0)
+      jekyll (>= 3.7, < 5.0)
+    jekyll-watch (2.2.1)
+      listen (~> 3.0)
+    just-the-docs (0.6.2)
+      jekyll (>= 3.8.5)
+      jekyll-include-cache
+      jekyll-seo-tag (>= 2.0)
+      rake (>= 12.3.1)
+    kramdown (2.4.0)
+      rexml
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
+    liquid (4.0.4)
+    listen (3.8.0)
+      rb-fsevent (~> 0.10, >= 0.10.3)
+      rb-inotify (~> 0.9, >= 0.9.10)
+    mercenary (0.4.0)
+    nokogiri (1.15.4-x86_64-linux)
+      racc (~> 1.4)
+    pathutil (0.16.2)
+      forwardable-extended (~> 2.6)
+    pdf-reader (2.11.0)
+      Ascii85 (~> 1.0)
+      afm (~> 0.2.1)
+      hashery (~> 2.0)
+      ruby-rc4
+      ttfunk
+    public_suffix (5.0.3)
+    racc (1.7.1)
+    rainbow (3.1.1)
+    rake (13.0.6)
+    rb-fsevent (0.11.2)
+    rb-inotify (0.10.1)
+      ffi (~> 1.0)
+    rexml (3.2.6)
+    rouge (4.1.3)
+    ruby-rc4 (0.1.5)
+    safe_yaml (1.0.5)
+    sass-embedded (1.69.4)
+      google-protobuf (~> 3.23)
+      rake (>= 13.0.0)
+    terminal-table (3.0.2)
+      unicode-display_width (>= 1.1.1, < 3)
+    timers (4.3.5)
+    ttfunk (1.7.0)
+    typhoeus (1.4.0)
+      ethon (>= 0.9.0)
+    unicode-display_width (2.5.0)
+    webrick (1.8.1)
+    yell (2.2.2)
+    zeitwerk (2.6.12)
+
+PLATFORMS
+  x86_64-linux
+
+DEPENDENCIES
+  html-proofer (= 5.0.8)
+  jekyll (= 4.3.2)
+  jekyll-sitemap (= 1.4.0)
+  just-the-docs (= 0.6.2)
+  rake (= 13.0.6)
+  webrick (= 1.8.1)
+
+RUBY VERSION
+   ruby 3.1.2p20
+
+BUNDLED WITH
+   2.3.7

website/README.md

@@ -7,18 +7,30 @@ statically generated using [Jekyll][jekyll].
 # Local development
 
 To view the website on `localhost`, first follow the [Jekyll installation
-instructions][jekyll-docs-installation]. Once done, in this directory execute:
+instructions][jekyll-docs-installation]. Once done, run the following Maven
+commands in the root of the repository to extract the (test) data from the bug
+patterns and Refaster rule collections and to transform this data into a
+Jekyll-digestible format. Unless and relevant Java code has been changed, these
+commands needs to be executed once.
+
+```sh
+mvn -T1C clean install -DskipTests -Dverification.skip
+mvn exec:java@generate-docs -pl documentation-support
+```
+
+Then to build the website for local development, execute in this directory:
 
 ```sh
 bundle install
-../generate-docs.sh && bundle exec jekyll serve --livereload
+bundle exec jekyll serve --livereload
 ```
 
 The website will now be [available][localhost-port-4000] on port 4000. Source
-code modifications (including the result of rerunning `../generate-docs.sh`)
-will automatically be reflected. (An exception is `_config.yml`: changes to
-this file require a server restart.) Subsequent server restarts do not require
-running `bundle install`, unless `Gemfile` has been updated in the interim.
+code modifications (including the result of rerunning `mvn
+exec:java@generate-docs -pl documentation-support`) will automatically be
+reflected. (An exception is `_config.yml`: changes to this file require a
+server restart.) Subsequent server restarts do not require running `bundle
+install`, unless `Gemfile` has been updated in the interim.
 
 If you are not familiar with Jekyll, be sure to check out its
 [documentation][jekyll-docs]. It is recommended to follow the provided

website/_config.yml

@@ -8,15 +8,40 @@ description: >-
 
 theme: just-the-docs
 plugins:
-  - jekyll-sitemap
+- jekyll-sitemap
 
 # Files and directories not to be deployed through GitHub pages.
 exclude:
-  - Gemfile
-  - Gemfile.lock
-  - generate-version-compatibility-overview.sh
-  - README.md
-  - vendor
+- Gemfile
+- Gemfile.lock
+- generate-version-compatibility-overview.sh
+- README.md
+- vendor
+
+collections:
+  bugpatterns:
+    output: true
+  refasterrules:
+    output: true
+
+defaults:
+- scope:
+    type: "bugpatterns"
+  values:
+    layout: "bugpattern"
+- scope:
+    type: "refasterrules"
+  values:
+    layout: "refasterrule"
+
+just_the_docs:
+  collections:
+    bugpatterns:
+      name: Bug Patterns
+      nav_fold: true
+    refasterrules:
+      name: Refaster Rules
+      nav_fold: true
 
 # See https://jekyllrb.com/docs/permalinks/#built-in-formats.
 permalink: pretty
@@ -25,9 +50,9 @@ permalink: pretty
 # See
 # https://just-the-docs.github.io/just-the-docs/docs/navigation-structure/#external-navigation-links.
 nav_external_links:
-  - title: Error Prone Support on GitHub
-    url: https://github.com/PicnicSupermarket/error-prone-support
-    hide_icon: false
+- title: Error Prone Support on GitHub
+  url: https://github.com/PicnicSupermarket/error-prone-support
+  hide_icon: false
 
 callouts:
   summary:
@@ -40,9 +65,9 @@ callouts:
 social:
   name: Picnic
   links:
-    - https://github.com/PicnicSupermarket
-    - https://twitter.com/picnic
-    - https://www.linkedin.com/company/picnictechnologies
+  - https://github.com/PicnicSupermarket
+  - https://twitter.com/picnic
+  - https://www.linkedin.com/company/picnictechnologies
 twitter:
   username: picnic
   card: summary

website/_data/compatibility.yml

@@ -1,8 +1,79 @@
 # An overview of Error Prone Support releases, along with compatible Error
 # Prone releases. This data was generated by `generate-version-compatibility-overview.sh`.
 releases:
+  - version: 0.18.0
+    compatible:
+      - "2.30.0"
+      - "2.31.0"
+      - "2.32.0"
+  - version: 0.17.0
+    compatible:
+      - "2.29.2"
+      - "2.29.1"
+      - "2.29.0"
+      - "2.28.0"
+      - "2.27.1"
+      - "2.27.0"
+      - "2.26.1"
+      - "2.26.0"
+      - "2.25.0"
+      - "2.24.1"
+      - "2.24.0"
+      - "2.23.0"
+  - version: 0.16.1
+    compatible:
+      - "2.29.2"
+      - "2.29.1"
+      - "2.29.0"
+      - "2.28.0"
+      - "2.27.1"
+      - "2.27.0"
+      - "2.26.1"
+      - "2.26.0"
+      - "2.25.0"
+      - "2.24.1"
+      - "2.24.0"
+      - "2.23.0"
+  - version: 0.16.0
+    compatible:
+      - "2.29.2"
+      - "2.29.1"
+      - "2.29.0"
+      - "2.28.0"
+      - "2.27.1"
+      - "2.27.0"
+      - "2.26.1"
+      - "2.26.0"
+      - "2.25.0"
+      - "2.24.1"
+      - "2.24.0"
+      - "2.23.0"
+  - version: 0.15.0
+    compatible:
+      - "2.29.2"
+      - "2.29.1"
+      - "2.29.0"
+      - "2.28.0"
+      - "2.27.1"
+      - "2.27.0"
+      - "2.26.1"
+      - "2.26.0"
+      - "2.25.0"
+      - "2.24.1"
+      - "2.24.0"
+      - "2.23.0"
   - version: 0.14.0
     compatible:
+      - "2.29.2"
+      - "2.29.1"
+      - "2.29.0"
+      - "2.28.0"
+      - "2.27.1"
+      - "2.27.0"
+      - "2.26.1"
+      - "2.26.0"
+      - "2.25.0"
+      - "2.24.1"
       - "2.24.0"
       - "2.23.0"
       - "2.22.0"

website/_data/severities.yml

@@ -0,0 +1,6 @@
+ERROR:
+  color: red
+WARNING:
+  color: yellow
+SUGGESTION:
+  color: green

website/_layouts/bugpattern.md

@@ -0,0 +1,94 @@
+---
+# XXX: To be implemented:
+# - Support for alt names.
+# - Support for explanations.
+# - Support for "can disable".
+# - Support for custom suppression annotations.
+layout: default
+---
+
+{% capture markdown_layout %}
+
+# {{ page.name }}
+
+{{ page.severity }}
+  {: .label .label-{{ site.data.severities[page.severity].color }} }
+
+{% for tag in page.tags %}
+{{ tag }}
+  {: .label }
+{% endfor %}
+
+<a href="https://github.com/PicnicSupermarket/error-prone-support/blob/master/{{ page.source }}" class="fs-3 btn external" target="_blank">
+    View source code on GitHub
+    <svg viewBox="0 0 24 24" aria-labelledby="svg-external-link-title">
+        <use xlink:href="#svg-external-link"></use>
+    </svg>
+</a>
+
+{: .summary-title }
+> Summary
+>
+> {{ page.summary }}
+
+{% comment %}
+  # XXX: Here, include a more elaborate explantion, if available.
+{% endcomment %}
+
+{: .note-title }
+> Suppression
+>
+> Suppress false positives by adding the suppression annotation `@SuppressWarnings("{{ page.name }}")` to
+> the enclosing element.
+>
+> Disable this pattern completely by adding `-Xep:{{ page.name }}:OFF` as compiler argument.
+> [Learn more][error-prone-flags].
+{% comment %}
+  # XXX: Create an internal page on documenting the usage of compiler flags.
+{% endcomment %}
+
+{% if page.replacement or page.identification %}
+
+## Samples
+
+{% comment %}
+  # XXX: Either make this "Samples" header useful, or drop it. (In which case
+  # the wrapping conjunctive guard should also go.)
+{% endcomment %}
+
+{% if page.replacement %}
+
+### Replacement
+
+Shows the difference in example code before and after the bug pattern is
+applied.
+
+{% for diff in page.replacement %}
+{% highlight diff %}
+{{ diff }}
+{% endhighlight %}
+{% endfor %}
+
+{% endif %}
+
+{% if page.identification %}
+
+### Identification
+
+Shows code lines which will (not) be flagged by this bug pattern. \
+A `//BUG: Diagnostic contains:` comment is placed above any violating line.
+
+{% for source in page.identification %}
+{% highlight java %}
+{{ source }}
+{% endhighlight %}
+{% endfor %}
+
+{% endif %}
+
+{% endif %}
+
+[error-prone-flags]: https://errorprone.info/docs/flags
+
+{% endcapture %}
+{{ markdown_layout | markdownify }}

website/_layouts/refasterrule.md

@@ -0,0 +1,78 @@
+---
+layout: default
+---
+
+{% capture markdown_layout %}
+
+# {{ page.name }}
+{: .no_toc }
+
+{{ page.severity }}
+  {: .label .label-{{ site.data.severities[page.severity].color }} }
+
+{% for tag in page.tags %}
+{{ tag }}
+  {: .label }
+{% endfor %}
+
+<a href="https://github.com/PicnicSupermarket/error-prone-support/blob/master/{{ page.source }}" class="fs-3 btn external" target="_blank">
+    View source code on GitHub
+    <svg viewBox="0 0 24 24" aria-labelledby="svg-external-link-title">
+        <use xlink:href="#svg-external-link"></use>
+    </svg>
+</a>
+
+{: .note-title }
+> Suppression
+>
+> Disable all rules by adding `-XepOpt:Refaster:NamePattern=^(?!{{page.name}}\$).*` as
+> compiler argument.
+{% comment %}
+  # XXX: Create an internal page on documenting the usage of compiler flags.
+{% endcomment %}
+
+<details open markdown="block">
+  <summary>
+    Table of contents
+  </summary>
+  {: .text-delta }
+  1. TOC
+  {:toc}
+</details>
+
+{% for rule in page.rules %}
+## {{rule.name}}
+
+{{ page.severity }}
+  {: .label .label-{{ site.data.severities[rule.severity].color }} }
+
+{% for tag in rule.tags %}
+{{ tag }}
+  {: .label }
+{% endfor %}
+
+{: .note-title }
+> Suppression
+>
+> Suppress false positives by adding the suppression annotation `@SuppressWarnings("{{rule.name}}")` to
+> the enclosing element.
+>
+> Disable this rule by adding `-XepOpt:Refaster:NamePattern=^(?!{{page.name}}\${{rule.name}}).*`
+> as compiler argument.
+{% comment %}
+  # XXX: Create an internal page on documenting the usage of compiler flags.
+{% endcomment %}
+
+### Samples
+{: .no_toc .text-delta }
+
+Shows the difference in example code before and after the Refaster rule is
+applied.
+
+{% highlight diff %}
+{{ rule.diff }}
+{% endhighlight %}
+{% endfor %}
+
+{% endcapture %}
+{{ markdown_layout | markdownify }}

website/_sass/color_schemes/_variables.scss

@@ -2,4 +2,4 @@
 // https://github.com/just-the-docs/just-the-docs/blob/main/_sass/support/_variables.scss.
 
 // Grid system.
-$nav-width: 400px;
+$nav-width: 25rem;

website/bugpatterns.md

@@ -1,8 +0,0 @@
----
-layout: default
-title: Bug Patterns
-nav_order: 2
-has_children: true
----
-
-# Bug Patterns

website/generate-version-compatibility-overview.sh

@@ -10,15 +10,21 @@ source "${HOME}/.sdkman/bin/sdkman-init.sh"
 
 set -e -u -o pipefail
 
+# Currently all released Error Prone Support versions are compatible with Java
+# 17.
+java_version=17.0.10-tem
+(set +u && echo n | sdk install java "${java_version}")
+sdk use java "${java_version}"
+
 output_file="$(dirname "${0}")/_data/compatibility.yml"
 
-ep_versions=$(
+ep_versions="$(
   git ls-remote \
       --exit-code --refs --sort='-v:refname' \
       https://github.com/google/error-prone.git \
       'v*.*' \
     | grep -oP '(?<=/v)[^/]+$'
-)
+)"
 
 work_dir="$(mktemp -d)"
 trap 'rm -rf -- "${work_dir=}"' INT TERM HUP EXIT
@@ -39,26 +45,43 @@ for eps_version in ${eps_versions}; do
   (set +u && echo n | sdk install maven "${mvn_version}")
   sdk use maven "${mvn_version}"
 
+  # Collect the list of checks supported by this version of Error Prone
+  # Support.
+  # XXX: Conditionally omit the `MethodReferenceUsage` exclusion once that
+  # check is production-ready.
+  mvn clean compile -Dverification.skip -DskipTests
+  checks="$(
+    find \
+       -path "*/META-INF/services/com.google.errorprone.bugpatterns.BugChecker" \
+       -not -path "*/error-prone-experimental/*" \
+       -not -path "*/error-prone-guidelines/*" \
+       -print0 \
+      | xargs -0 grep -hoP '[^.]+$' \
+      | grep -v '^MethodReferenceUsage$' \
+      | paste -s -d ',' -
+    )"
+
   # Remove any Error Prone flags used by this build that may not be compatible
   # with the targeted version of Error Prone. Removal of these build flags does
   # not influence the compatibility assessment.
   sed -i -r 's,-XepAllSuggestionsAsWarnings|-Xep:\w+:\w+,,g' pom.xml
 
   # Using each Error Prone release, attempt to build and test the source, while
-  # also applying the Maven Central-hosted Refaster rules. This determines
-  # source and behavioral (in)compatibility with Error Prone APIs, while also
-  # assessing whether the Refaster rules are deserialization-compatible.
+  # also applying the Maven Central-hosted Error Prone Support-defined checks
+  # and Refaster rules. This determines source and behavioral (in)compatibility
+  # with Error Prone APIs, while also assessing whether the Refaster rules are
+  # deserialization-compatible.
   for ep_version in ${ep_versions}; do
     echo "Testing Error Prone Support ${eps_version} with Error Prone ${ep_version}..."
     mvn clean test \
         -Perror-prone \
-        -Derror-prone.patch-checks=Refaster \
+        -Derror-prone.patch-checks="${checks}" \
         -Ppatch \
         -Pself-check \
         -Dverification.skip \
         -Dversion.error-prone-orig="${ep_version}" \
       && echo "SUCCESS: { \"eps_version\": \"${eps_version}\", \"ep_version\": \"${ep_version}\" }" || true
-    # Undo any changes applied by Refaster.
+    # Undo any changes applied by the checks.
     git checkout -- '*.java'
   done
 done | tee "${build_log}"