xxx

Add openrewrite dependencies
Update the workshop branch and apply best practices of EPS
2026-03-10 08:11:25 +00:00 · 2024-04-09 09:56:06 +02:00 · 2024-04-09 09:00:28 +02:00 · 2024-04-05 10:08:52 +02:00 · 2024-04-05 07:58:59 +02:00 · 2024-04-05 07:58:58 +02:00
86 changed files with 3545 additions and 619 deletions
--- a/.github/ISSUE_TEMPLATE/bug_report.md
+++ b/.github/ISSUE_TEMPLATE/bug_report.md
@@ -42,9 +42,9 @@ Please replace this sentence with log output, if applicable.
 <!-- Please complete the following information: -->

 - Operating system (e.g. MacOS Monterey).
- Java version (i.e. `java --version`, e.g. `17.0.8`).
- Error Prone version (e.g. `2.18.0`).
- Error Prone Support version (e.g. `0.9.0`).
+- Java version (i.e. `java --version`, e.g. `17.0.10`).
+- Error Prone version (e.g. `2.25.0`).
+- Error Prone Support version (e.g. `0.15.0`).

 ### Additional context

--- a/.github/release.yml
+++ b/.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"
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -7,24 +7,34 @@ permissions:
  contents: read
 jobs:
  build:
+    if: github.repository == 'PicnicSupermarket/error-prone-support'
    strategy:
      matrix:
        os: [ ubuntu-22.04 ]
-        jdk: [ 17.0.8, 21.0.0 ]
+        jdk: [ 17.0.10, 21.0.2 ]
        distribution: [ temurin ]
        experimental: [ false ]
        include:
          - os: macos-14
-            jdk: 17.0.8
+            jdk: 17.0.10
            distribution: temurin
            experimental: false
          - os: windows-2022
-            jdk: 17.0.8
+            jdk: 17.0.10
            distribution: temurin
            experimental: false
    runs-on: ${{ matrix.os }}
    continue-on-error: ${{ matrix.experimental }}
    steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            github.com:443
+            jitpack.io: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,
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -13,6 +13,7 @@ permissions:
  contents: read
 jobs:
  analyze:
+    if: github.repository == 'PicnicSupermarket/error-prone-support'
    strategy:
      matrix:
        language: [ java, ruby ]
@@ -21,20 +22,31 @@ jobs:
      security-events: write
    runs-on: ubuntu-22.04
    steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            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
        with:
-          java-version: 17.0.8
+          java-version: 17.0.10
          java-distribution: temurin
          maven-version: 3.9.6
      - name: Initialize CodeQL
-        uses: github/codeql-action/init@b7bf0a3ed3ecfa44160715d7c442788f65f0f923 # v3.23.2
+        uses: github/codeql-action/init@1b1aada464948af03b950897e5eb522f92603cc2 # v3.24.9
        with:
          languages: ${{ matrix.language }}
      - name: Perform minimal build
        if: matrix.language == 'java'
        run: mvn -T1C clean package -DskipTests -Dverification.skip
      - name: Perform CodeQL analysis
-        uses: github/codeql-action/analyze@b7bf0a3ed3ecfa44160715d7c442788f65f0f923 # v3.23.2
+        uses: github/codeql-action/analyze@1b1aada464948af03b950897e5eb522f92603cc2 # v3.24.9
        with:
          category: /language:${{ matrix.language }}
--- a/.github/workflows/deploy-website.yml
+++ b/.github/workflows/deploy-website.yml
@@ -9,18 +9,46 @@ concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
 jobs:
  build:
+    if: github.repository == 'PicnicSupermarket/error-prone-support'
    runs-on: ubuntu-22.04
    steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
+        with:
+          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
        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
        with:
          persist-credentials: false
-      - uses: ruby/setup-ruby@bd03e04863f52d169e18a2b190e8fa6b84938215 # v1.170.0
+      - uses: ruby/setup-ruby@5f19ec79cedfadb78ab837f95b87734d0003c899 # v1.173.0
        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: Generate documentation
        run: ./generate-docs.sh
      - name: Build website with Jekyll
@@ -46,6 +74,13 @@ jobs:
      name: github-pages
      url: ${{ steps.deployment.outputs.page_url }}
    steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
+        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
--- a/.github/workflows/openssf-scorecard.yml
+++ b/.github/workflows/openssf-scorecard.yml
@@ -14,12 +14,28 @@ permissions:
  contents: read
 jobs:
  analyze:
+    if: github.repository == 'PicnicSupermarket/error-prone-support'
    permissions:
      contents: read
      security-events: write
      id-token: write
    runs-on: ubuntu-22.04
    steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            api.github.com:443
+            api.osv.dev:443
+            api.securityscorecards.dev:443
+            fulcio.sigstore.dev:443
+            github.com:443
+            oss-fuzz-build-logs.storage.googleapis.com:443
+            rekor.sigstore.dev:443
+            tuf-repo-cdn.sigstore.dev:443
+            www.bestpractices.dev:443
      - name: Check out code
        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
        with:
@@ -31,6 +47,6 @@ jobs:
          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@1b1aada464948af03b950897e5eb522f92603cc2 # v3.24.9
        with:
          sarif_file: results.sarif
--- a/.github/workflows/pitest-analyze-pr.yml
+++ b/.github/workflows/pitest-analyze-pr.yml
@@ -9,13 +9,22 @@ permissions:
  contents: read
 jobs:
  analyze-pr:
+    if: github.repository == 'PicnicSupermarket/error-prone-support'
    runs-on: ubuntu-22.04
    steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            github.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
        with:
          checkout-fetch-depth: 2
-          java-version: 17.0.8
+          java-version: 17.0.10
          java-distribution: temurin
          maven-version: 3.9.6
      - name: Run Pitest
--- a/.github/workflows/pitest-update-pr.yml
+++ b/.github/workflows/pitest-update-pr.yml
@@ -11,7 +11,7 @@ permissions:
  actions: read
 jobs:
  update-pr:
-    if: ${{ github.event.workflow_run.conclusion == 'success' }}
+    if: ${{ github.event.workflow_run.conclusion == 'success' && github.repository == 'PicnicSupermarket/error-prone-support' }}
    permissions:
      actions: read
      checks: write
@@ -19,14 +19,23 @@ jobs:
      pull-requests: write
    runs-on: ubuntu-22.04
    steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            api.github.com:443
+            github.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
        with:
-          java-version: 17.0.8
+          java-version: 17.0.10
          java-distribution: temurin
          maven-version: 3.9.6
      - name: Download Pitest analysis artifact
-        uses: dawidd6/action-download-artifact@f6b0bace624032e30a85a8fd9c1a7f8f611f5737 # v3.1.0
+        uses: dawidd6/action-download-artifact@09f2f74827fd3a8607589e5ad7f9398816f540fe # v3.1.4
        with:
          workflow: ${{ github.event.workflow_run.workflow_id }}
          name: pitest-reports
--- a/.github/workflows/run-integration-tests.yml
+++ b/.github/workflows/run-integration-tests.yml
@@ -9,20 +9,32 @@ name: "Integration tests"
 on:
  issue_comment:
    types: [ created ]
+  pull_request:
+  push:
 permissions:
  contents: read
 jobs:
  run-integration-tests:
    name: On-demand integration test
-    if: |
-      github.event.issue.pull_request && contains(github.event.comment.body, '/integration-test')
    runs-on: ubuntu-22.04
    steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            checkstyle.org:443
+            github.com:443
+            oss.sonatype.org:443
+            raw.githubusercontent.com:443
+            repo.maven.apache.org:443
+            repository.sonatype.org:443
      - name: Check out code and set up JDK and Maven
        uses: s4u/setup-maven-action@6d44c18d67d9e1549907b8815efa5e4dada1801b # v1.12.0
        with:
          checkout-ref: "refs/pull/${{ github.event.issue.number }}/head"
-          java-version: 17.0.8
+          java-version: 17.0.10
          java-distribution: temurin
          maven-version: 3.9.6
      - name: Install project to local Maven repository
--- a/.github/workflows/sonarcloud.yml
+++ b/.github/workflows/sonarcloud.yml
@@ -18,11 +18,23 @@ jobs:
      contents: read
    runs-on: ubuntu-22.04
    steps:
+      - name: Install Harden-Runner
+        uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
+        with:
+          disable-sudo: true
+          egress-policy: block
+          allowed-endpoints: >
+            ea6ne4j2sb.execute-api.eu-central-1.amazonaws.com:443
+            github.com:443
+            repo.maven.apache.org:443
+            sc-cleancode-sensorcache-eu-central-1-prod.s3.amazonaws.com:443
+            scanner.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
        with:
          checkout-fetch-depth: 0
-          java-version: 17.0.8
+          java-version: 17.0.10
          java-distribution: temurin
          maven-version: 3.9.6
      - name: Create missing `test` directory
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@
 .DS_Store
 .factorypath
 .idea
+!.idea/icon.svg
 .project
 .settings
 target
--- a/.idea/icon.svg
+++ b/.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)">
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+            </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;"/>
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+            </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>
--- a/.renovaterc.json
+++ b/.renovaterc.json
@@ -13,6 +13,7 @@
    },
    {
      "matchDepNames": [
+        "dawidd6/action-download-artifact",
        "github/codeql-action",
        "ruby/setup-ruby"
      ],
--- a/documentation-support/pom.xml
+++ b/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>0.16.2-SNAPSHOT</version>
    </parent>

    <artifactId>documentation-support</artifactId>
--- a/error-prone-contrib/pom.xml
+++ b/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>0.16.2-SNAPSHOT</version>
    </parent>

    <artifactId>error-prone-contrib</artifactId>
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/EmptyMonoZip.java
+++ b/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));
+  }
+}
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/LexicographicalAnnotationAttributeListing.java
+++ b/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";
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/OptionalOrElse.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/OptionalOrElse.java
@@ -0,0 +1,135 @@
+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.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.IdentifierTree;
+import com.sun.source.tree.LiteralTree;
+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.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: Consider also implementing the inverse, in which `.orElseGet(() -> someConstant)` is
+// flagged.
+// XXX: Once the `MethodReferenceUsageCheck` 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 `@Matches` constraint that implements the `requiresComputation`
+// logic.
+@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 OptionalOrElse extends BugChecker implements MethodInvocationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  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 OptionalOrElse} instance. */
+  public OptionalOrElse() {}
+
+  @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 (!requiresComputation(argument) || 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);
+  }
+
+  /**
+   * Tells whether the given expression contains anything other than a literal or a (possibly
+   * dereferenced) variable or constant.
+   */
+  private static boolean requiresComputation(ExpressionTree tree) {
+    return !(tree instanceof IdentifierTree
+        || tree instanceof LiteralTree
+        || (tree instanceof MemberSelectTree memberSelect
+            && !requiresComputation(memberSelect.getExpression()))
+        || ASTHelpers.constValue(tree) != null);
+  }
+
+  /** 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 (requiresComputation(memberSelect.getExpression())) {
+      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());
+  }
+}
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/StaticImport.java
+++ b/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",
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/CollectionRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/CollectionRules.java
@@ -39,7 +39,7 @@ 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) {
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ComparatorRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ComparatorRules.java
@@ -16,8 +16,11 @@ 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;
@@ -92,6 +95,24 @@ 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
@@ -419,4 +440,34 @@ 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;
+    }
+  }
 }
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/EqualityRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/EqualityRules.java
@@ -30,8 +30,9 @@ 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
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/OptionalRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/OptionalRules.java
@@ -360,7 +360,7 @@ 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("NestedOptionals")
    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 +386,13 @@ 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 +446,7 @@ 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
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java
@@ -1205,6 +1205,19 @@ final class ReactorRules {
    }
  }

+  /** Prefer {@link Flux#fromIterable(Iterable)} over less efficient alternatives. */
+  static final class FluxFromIterable<T> {
+    @BeforeTemplate
+    Flux<T> before(Collection<T> collection) {
+      return Flux.fromStream(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.
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/StreamRules.java
+++ b/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
--- a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/EmptyMonoZipTest.java
+++ b/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();
+  }
+}
--- a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/OptionalOrElseTest.java
+++ b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/OptionalOrElseTest.java
@@ -0,0 +1,135 @@
+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 OptionalOrElseTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(OptionalOrElse.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import com.google.errorprone.refaster.Refaster;",
+            "import java.util.Optional;",
+            "",
+            "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\"));",
+            "",
+            "    // 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(OptionalOrElse.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);
+  }
+}
--- a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/Slf4jLogStatementTest.java
+++ b/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);",
            "",
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ComparatorRulesTestInput.java
+++ b/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));
  }
@@ -173,4 +178,16 @@ 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());
+  }
 }
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ComparatorRulesTestOutput.java
+++ b/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);
  }
@@ -163,4 +169,16 @@ 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);
+  }
 }
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestInput.java
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestInput.java
@@ -21,8 +21,10 @@ final class EqualityRulesTest implements RefasterRuleCollectionTestCase {
    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());
  }

  boolean testEqualsPredicate() {
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestOutput.java
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestOutput.java
@@ -21,6 +21,8 @@ final class EqualityRulesTest implements RefasterRuleCollectionTestCase {
    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);
  }
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/OptionalRulesTestInput.java
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/OptionalRulesTestInput.java
@@ -120,10 +120,12 @@ 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 +138,7 @@ 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);
  }
 }
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/OptionalRulesTestOutput.java
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/OptionalRulesTestOutput.java
@@ -120,7 +120,9 @@ 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 +134,7 @@ 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();
  }
 }
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestInput.java
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestInput.java
@@ -432,6 +432,10 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
        Flux.just(ImmutableList.of("bar")).concatMap(Flux::fromIterable, 2));
  }

+  Flux<String> testFluxFromIterable() {
+    return Flux.fromStream(ImmutableList.of("foo").stream());
+  }
+
  ImmutableSet<Mono<Integer>> testFluxCountMapMathToIntExact() {
    return ImmutableSet.of(
        Flux.just(1).collect(toImmutableList()).map(Collection::size),
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestOutput.java
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestOutput.java
@@ -427,6 +427,10 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
        Flux.just(ImmutableList.of("bar")).concatMapIterable(identity(), 2));
  }

+  Flux<String> testFluxFromIterable() {
+    return Flux.fromIterable(ImmutableList.of("foo"));
+  }
+
  ImmutableSet<Mono<Integer>> testFluxCountMapMathToIntExact() {
    return ImmutableSet.of(
        Flux.just(1).count().map(Math::toIntExact),
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/StreamRulesTestInput.java
+++ b/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() {
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/StreamRulesTestOutput.java
+++ b/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() {
--- a/error-prone-experimental/pom.xml
+++ b/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>0.16.2-SNAPSHOT</version>
    </parent>

    <artifactId>error-prone-experimental</artifactId>
--- a/error-prone-guidelines/pom.xml
+++ b/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>0.16.2-SNAPSHOT</version>
    </parent>

    <artifactId>error-prone-guidelines</artifactId>
--- a/error-prone-utils/pom.xml
+++ b/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>0.16.2-SNAPSHOT</version>
    </parent>

    <artifactId>error-prone-utils</artifactId>
--- a/integration-tests/checkstyle-expected-changes.patch
+++ b/integration-tests/checkstyle-expected-changes.patch
--- a/integration-tests/checkstyle-expected-warnings.txt
+++ b/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)
--- a/integration-tests/checkstyle-init.patch
+++ b/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
  */
--- a/integration-tests/checkstyle.sh
+++ b/integration-tests/checkstyle.sh
@@ -9,7 +9,7 @@ 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
+revision=checkstyle-10.14.0

 if [ "${#}" -gt 2 ] || ([ "${#}" = 2 ] && [ "${1:---sync}" != '--sync' ]); then
  echo "Usage: ${0} [--sync] [<report_directory>]"
@@ -61,24 +61,28 @@ 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 "${error_prone_support_root}" -path "*/META-INF/services/com.google.errorprone.bugpatterns.BugChecker" -print0 \
+  find "${error_prone_support_root}" \
+     -path "*/META-INF/services/com.google.errorprone.bugpatterns.BugChecker" \
+     -not -path "*/error-prone-experimental/*" \
+     -not -path "*/error-prone-guidelines/*" \
+     -not -path "*/error-prone-contrib/*" \
+     -print0 \
    | xargs -0 "${grep_command}" -hoP '[^.]+$' \
-    | "${grep_command}" -v ErrorProneRuntimeClasspath \
    | paste -s -d ',' -
-)"
+) -XepOpt:Refaster:NamePattern=.*Workshop.*"

-# 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 "${grep_command}" -hoP '[^.]+$' \
+  find "${error_prone_support_root}" \
+     -path "*/META-INF/services/com.google.errorprone.bugpatterns.BugChecker" \
+     -not -path "*/error-prone-experimental/*" \
+     -not -path "*/error-prone-guidelines/*" \
+     -not -path "*/error-prone-contrib/*" \
+     -print0 \
+    | xargs -0 "${grep_command}" -hoP "[^.]+$' \
    | "${sed_command}" -r 's,(.*),-Xep:\1:WARN,' \
-    | "${grep_command}" -v ErrorProneRuntimeClasspath \
    | paste -s -d ' ' -
-)"
+) -XepOpt:Refaster:NamePattern=.*Workshop.*"

 echo "Shared build flags: ${shared_build_flags}"
 echo "Error Prone patch flags: ${error_prone_patch_flags}"
@@ -166,6 +170,7 @@ mvn ${shared_build_flags} \
      -Dtest='
        !MetadataGeneratorUtilTest#metadataFilesGenerationAllFiles,
        !XdocsJavaDocsTest#allCheckSectionJavaDocs' \
+      -Dstyle.color=always \
    | tee "${validation_build_log}" \
  || failure=1

@@ -189,12 +194,15 @@ else
  # 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.'
+    echo 'There are unexpected changes.'
+    echo "Inspect the changes here: ${report_directory}/${test_name}-diff-of-diffs-changes.patch"
+    diff -u "${expected_changes}" "${actual_changes}" > "${report_directory}/${test_name}-diff-of-diffs-changes.patch"
    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.'
+    echo 'Diagnostics output changed.'
+    diff -u "${expected_warnings}" "${actual_warnings}" > "${report_directory}/${test_name}-diff-of-diffs-warnings.patch"
    failure=1
  fi
 fi
--- a/pom.xml
+++ b/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>0.16.2-SNAPSHOT</version>
    <packaging>pom</packaging>

    <name>Picnic :: Error Prone Support</name>
@@ -48,6 +48,7 @@
        <module>refaster-runner</module>
        <module>refaster-support</module>
        <module>refaster-test-support</module>
+        <module>workshop</module>
    </modules>

    <scm child.scm.developerConnection.inherit.append.path="false" child.scm.url.inherit.append.path="false">
@@ -148,7 +149,7 @@
        <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>2024-03-15T12:04:44Z</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
@@ -207,17 +208,17 @@
        <version.auto-service>1.1.1</version.auto-service>
        <version.auto-value>1.10.4</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-fork>v${version.error-prone-orig}-picnic-2</version.error-prone-fork>
+        <version.error-prone-orig>2.26.1</version.error-prone-orig>
+        <version.error-prone-slf4j>0.1.23</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.mockito>5.11.0</version.mockito>
        <version.nopen-checker>1.0.1</version.nopen-checker>
-        <version.nullaway>0.10.23</version.nullaway>
+        <version.nullaway>0.10.25</version.nullaway>
        <version.pitest-git>1.1.4</version.pitest-git>
-        <version.rewrite-templating>1.5.0</version.rewrite-templating>
+        <version.rewrite-templating>1.6.3</version.rewrite-templating>
        <version.surefire>3.2.3</version.surefire>
    </properties>

@@ -296,7 +297,7 @@
            <dependency>
                <groupId>com.fasterxml.jackson</groupId>
                <artifactId>jackson-bom</artifactId>
-                <version>2.16.1</version>
+                <version>2.17.0</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
@@ -328,7 +329,7 @@
            <dependency>
                <groupId>com.google.googlejavaformat</groupId>
                <artifactId>google-java-format</artifactId>
-                <version>1.19.2</version>
+                <version>1.22.0</version>
            </dependency>
            <dependency>
                <groupId>com.google.guava</groupId>
@@ -338,14 +339,14 @@
            <dependency>
                <groupId>com.google.guava</groupId>
                <artifactId>guava-bom</artifactId>
-                <version>33.0.0-jre</version>
+                <version>33.1.0-jre</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.google.truth</groupId>
                <artifactId>truth</artifactId>
-                <version>1.4.0</version>
+                <version>1.4.2</version>
            </dependency>
            <dependency>
                <groupId>com.jakewharton.nopen</groupId>
@@ -360,7 +361,7 @@
            <dependency>
                <groupId>io.projectreactor</groupId>
                <artifactId>reactor-bom</artifactId>
-                <version>2023.0.3</version>
+                <version>2023.0.4</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
@@ -372,12 +373,12 @@
            <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>2.2.21</version>
            </dependency>
            <dependency>
                <groupId>jakarta.servlet</groupId>
@@ -407,20 +408,12 @@
            <dependency>
                <groupId>net.bytebuddy</groupId>
                <artifactId>byte-buddy</artifactId>
-                <version>1.14.11</version>
-            </dependency>
-            <!-- Specified so that Renovate will file Maven upgrade PRs, which
-            subsequently will cause `maven-enforcer-plugin` to require that
-            developers build the project using the latest Maven release. -->
-            <dependency>
-                <groupId>org.apache.maven</groupId>
-                <artifactId>maven-plugin-api</artifactId>
-                <version>${version.maven}</version>
+                <version>1.14.13</version>
            </dependency>
            <dependency>
                <groupId>org.aspectj</groupId>
                <artifactId>aspectjweaver</artifactId>
-                <version>1.9.21.1</version>
+                <version>1.9.22</version>
            </dependency>
            <dependency>
                <groupId>org.assertj</groupId>
@@ -442,7 +435,7 @@
            <dependency>
                <groupId>org.immutables</groupId>
                <artifactId>value-annotations</artifactId>
-                <version>2.10.0</version>
+                <version>2.10.1</version>
            </dependency>
            <dependency>
                <groupId>org.jspecify</groupId>
@@ -466,7 +459,7 @@
            <dependency>
                <groupId>org.mongodb</groupId>
                <artifactId>mongodb-driver-core</artifactId>
-                <version>4.11.1</version>
+                <version>5.0.1</version>
            </dependency>
            <dependency>
                <groupId>org.openrewrite</groupId>
@@ -476,7 +469,7 @@
            <dependency>
                <groupId>org.openrewrite.recipe</groupId>
                <artifactId>rewrite-recipe-bom</artifactId>
-                <version>2.6.4</version>
+                <version>2.8.1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
@@ -490,19 +483,19 @@
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-framework-bom</artifactId>
-                <version>6.1.4</version>
+                <version>6.1.5</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>3.2.4</version>
            </dependency>
            <dependency>
                <groupId>org.springframework.security</groupId>
                <artifactId>spring-security-bom</artifactId>
-                <version>6.2.1</version>
+                <version>6.2.3</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
@@ -520,7 +513,7 @@
                <plugin>
                    <groupId>com.github.ekryd.sortpom</groupId>
                    <artifactId>sortpom-maven-plugin</artifactId>
-                    <version>3.3.0</version>
+                    <version>3.4.1</version>
                    <configuration>
                        <createBackupFile>false</createBackupFile>
                        <encoding>${project.build.sourceEncoding}</encoding>
@@ -577,7 +570,7 @@
                <plugin>
                    <groupId>de.thetaphi</groupId>
                    <artifactId>forbiddenapis</artifactId>
-                    <version>3.6</version>
+                    <version>3.7</version>
                    <configuration>
                        <bundledSignatures>
                            <bundledSignature>jdk-internal</bundledSignature>
@@ -624,7 +617,7 @@
                <plugin>
                    <groupId>io.github.git-commit-id</groupId>
                    <artifactId>git-commit-id-maven-plugin</artifactId>
-                    <version>7.0.0</version>
+                    <version>8.0.2</version>
                    <configuration>
                        <injectAllReactorProjects>true</injectAllReactorProjects>
                        <runOnlyOnce>true</runOnlyOnce>
@@ -891,7 +884,7 @@
                        <dependency>
                            <groupId>com.puppycrawl.tools</groupId>
                            <artifactId>checkstyle</artifactId>
-                            <version>10.13.0</version>
+                            <version>10.15.0</version>
                        </dependency>
                        <dependency>
                            <groupId>io.spring.nohttp</groupId>
@@ -916,7 +909,7 @@
                <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
@@ -1041,9 +1034,6 @@
                            <requireJavaVersion>
                                <version>${version.jdk}</version>
                            </requireJavaVersion>
-                            <requireMavenVersion>
-                                <version>${version.maven}</version>
-                            </requireMavenVersion>
                            <requireNoRepositories />
                            <requirePluginVersions />
                            <requireUpperBoundDeps />
@@ -1053,7 +1043,7 @@
                        <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 +1058,7 @@
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-gpg-plugin</artifactId>
-                    <version>3.1.0</version>
+                    <version>3.2.2</version>
                    <executions>
                        <execution>
                            <id>sign-artifacts</id>
@@ -1351,7 +1341,7 @@
                <plugin>
                    <groupId>org.gaul</groupId>
                    <artifactId>modernizer-maven-plugin</artifactId>
-                    <version>2.7.0</version>
+                    <version>2.8.0</version>
                    <configuration>
                        <exclusionPatterns>
                            <!-- The plugin suggests replacing usages of
@@ -1382,7 +1372,7 @@
                <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 +1384,7 @@
                <plugin>
                    <groupId>org.kordamp.maven</groupId>
                    <artifactId>pomchecker-maven-plugin</artifactId>
-                    <version>1.10.0</version>
+                    <version>1.11.0</version>
                    <configuration>
                        <failOnError>false</failOnError>
                        <release>false</release>
@@ -1466,7 +1456,7 @@
                <plugin>
                    <groupId>org.sonarsource.scanner.maven</groupId>
                    <artifactId>sonar-maven-plugin</artifactId>
-                    <version>3.10.0.2594</version>
+                    <version>3.11.0.3922</version>
                </plugin>
            </plugins>
        </pluginManagement>
--- a/refaster-compiler/pom.xml
+++ b/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>0.16.2-SNAPSHOT</version>
    </parent>

    <artifactId>refaster-compiler</artifactId>
--- a/refaster-runner/pom.xml
+++ b/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>0.16.2-SNAPSHOT</version>
    </parent>

    <artifactId>refaster-runner</artifactId>
--- a/refaster-runner/src/main/java/tech/picnic/errorprone/refaster/runner/Refaster.java
+++ b/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();
  }
--- a/refaster-support/pom.xml
+++ b/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>0.16.2-SNAPSHOT</version>
    </parent>

    <artifactId>refaster-support</artifactId>
--- a/refaster-test-support/pom.xml
+++ b/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>0.16.2-SNAPSHOT</version>
    </parent>

    <artifactId>refaster-test-support</artifactId>
--- a/website/_data/compatibility.yml
+++ b/website/_data/compatibility.yml
@@ -1,8 +1,36 @@
 # 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: 0.16.1
+    compatible:
+      - "2.26.1"
+      - "2.26.0"
+      - "2.25.0"
+      - "2.24.1"
+      - "2.24.0"
+      - "2.23.0"
+  - version: 0.16.0
+    compatible:
+      - "2.26.1"
+      - "2.26.0"
+      - "2.25.0"
+      - "2.24.1"
+      - "2.24.0"
+      - "2.23.0"
+  - version: 0.15.0
+    compatible:
+      - "2.26.1"
+      - "2.26.0"
+      - "2.25.0"
+      - "2.24.1"
+      - "2.24.0"
+      - "2.23.0"
  - version: 0.14.0
    compatible:
+      - "2.26.1"
+      - "2.26.0"
+      - "2.25.0"
+      - "2.24.1"
      - "2.24.0"
      - "2.23.0"
      - "2.22.0"
--- a/website/generate-version-compatibility-overview.sh
+++ b/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}"
--- a/workshop/README.md
+++ b/workshop/README.md
@@ -0,0 +1,108 @@
+# Error Prone Workshop
+
+XXX: @Rick update the slides.
+
+## Initial setup of the workshop
+
+1. Start by cloning this repository locally from GitHub.
+2. Checkout the `workshop` branch.
+3. Make sure to run `mvn clean install` in the root of this repository.
+4. Open your code editor and familiarize yourself with the project structure.
+
+In IntelliJ IDEA (or your preferred editor), try to run the
+`WorkshopRefasterRulesTest` test. You might see the following error:
+
+```
+java: exporting a package from system module jdk.compiler is not allowed with --release
+```
+
+If this happens, go to _Settings -> Build, Execution, Deployment -> Compiler ->
+Java Compiler_ and deselect the option _Use '--release' option for
+cross-compilation (Java 9 and later)_.
+
+Now the project is ready for the workshop.
+
+## Part 1: Writing Refaster rules
+
+During this part of the workshop we will implement multiple Refaster rules.
+
+Go to the `workshop` module and open the
+`tech.picnic.errorprone.workshop.refasterrules` package. There you can find one
+example and 5 different exercises to do. Make sure to check out the
+`WorkshopRefasterRulesTest.java` class where you can enable tests. Per
+assignment there is a test in this class that one can enable (by dropping the
+`@Disabled` annotation) to validate your changes. The goal is to implement or
+improve the Refaster rules such that the enabled tests pass.
+
+Tips:
+
+* Go through the exercises in the proposed order.
+* The `XXX:` comments explains what needs to happen.
+* See the test cases for each Refaster rule by looking for the name of the
+  Refaster rule prefixed with `test`. For example, the
+  `WorkshopAssignment0Rules.java` rule collection has a Refaster rule named
+  `ExampleStringIsEmpty`. In the `WorkshopAssignment0RulesTestInput.java` and
+  `WorkshopAssignment0RulesTestOutput.java` files there is a
+  `testExampleStringIsEmpty` method that shows the input and output to test the
+  Refaster rule.
+
+## Part 2: Writing Error Prone checks
+
+During this part of the workshop we will implement parts of multiple Error
+Prone `BugChecker`s. Each of these classes contain `XXX` comments explaining
+what needs to be implemented. However, before diving in, make sure to first
+navigate to a check's associated test class to drop the class-level `@Disabled`
+annotation. Upon initial execution the tests will fail; the goal is to get then
+to pass.
+
+Some utility classes that you can use:
+
+* `com.google.errorprone.util.ASTHelpers`: contains many common operations on
+  the Abstract Syntax Tree.
+* `com.google.errorprone.fixes.SuggestedFixes`: contains helper methods for
+  creating `Fix`es.
+
+To see the impact of the newly introduced Error Prone checks [re-trigger the
+integration test framework](#validating-changes-with-the-integration-tests).
+
+## Part 3 (optional): Validating changes with the integration tests
+
+We created an integration testing framework that allows us to see the impact of
+the rules that are created. This testing framework can be executed locally and
+via GitHub Actions.
+
+If you still have more than 10-15 minutes left, and you want to test this
+locally, run the following commands:
+
+```sh
+mvn clean install -DskipTests -Dverification.skip
+./integration-tests/checkstyle-10.12.4.sh
+```
+
+Once the process is complete, and changes are introduced, the following output
+will be printed:
+
+```
+There are unexpected changes.
+Inspect the changes here: /tmp/tmp.Cmr423L1pA/checkstyle-10.12.4-diff-of-diffs-changes.patch
+```
+
+This file is be provided for your review using your preferred text editor.
+Alternatively, you can also navigate to the repository by going to the
+`./integration-tests/.repos/checkstyle` directory and executing `git log -p` to
+view the commit history and associated changes.
+
+This shows the impact of the rules that you wrote when they are applied to
+Checkstyle!
+
+The other option is to execute the integration test via GitHub Actions. You
+only need to commit and push to the branch. This will trigger execution of the
+integration tests, which will run for about 10 minutes. When the build is
+finished, go to the _Actions_ tab in your fork and navigate to your most recent
+commit and click on it. Then click on _Summary_ and download the artifact
+`integration-test-checkstyle-10.12.4` at the bottom. Once done, unzip the
+artifact and inspect the `checkstyle-10.12.4-diff-of-diffs-changes.patch` file
+to see the changes.
+
+[eps-github]: https://github.com/PicnicSupermarket/error-prone-support
+[eps-workshop-jfall]: https://drive.google.com/file/d/1Es1OuSUmPHSt3BjeCWfrXfoF-cJkkA1A/view
--- a/workshop/pom.xml
+++ b/workshop/pom.xml
@@ -0,0 +1,150 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>tech.picnic.error-prone-support</groupId>
+        <artifactId>error-prone-support</artifactId>
+        <version>0.16.2-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>workshop</artifactId>
+
+    <name>Picnic :: Error Prone Support :: Workshop</name>
+    <description>Project for the Error Prone Workshop.</description>
+    <url>https://error-prone.picnic.tech</url>
+
+    <dependencies>
+        <dependency>
+            <groupId>${groupId.error-prone}</groupId>
+            <artifactId>error_prone_annotation</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>${groupId.error-prone}</groupId>
+            <artifactId>error_prone_annotations</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>${groupId.error-prone}</groupId>
+            <artifactId>error_prone_check_api</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>${groupId.error-prone}</groupId>
+            <artifactId>error_prone_core</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>${groupId.error-prone}</groupId>
+            <artifactId>error_prone_test_helpers</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>error-prone-utils</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>refaster-compiler</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>refaster-support</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>refaster-test-support</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.google.auto.service</groupId>
+            <artifactId>auto-service-annotations</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.aspectj</groupId>
+            <artifactId>aspectjweaver</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-params</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.openrewrite</groupId>
+            <artifactId>rewrite-core</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.openrewrite</groupId>
+            <artifactId>rewrite-java</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.openrewrite</groupId>
+            <artifactId>rewrite-java-11</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.openrewrite</groupId>
+            <artifactId>rewrite-templating</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-context</artifactId>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-compiler-plugin</artifactId>
+                    <configuration>
+                        <annotationProcessorPaths combine.children="append">
+                            <path>
+                                <groupId>${project.groupId}</groupId>
+                                <artifactId>refaster-compiler</artifactId>
+                                <version>${project.version}</version>
+                            </path>
+                            <path>
+                                <groupId>${project.groupId}</groupId>
+                                <artifactId>refaster-support</artifactId>
+                                <version>${project.version}</version>
+                            </path>
+                        </annotationProcessorPaths>
+                        <compilerArgs combine.children="append">
+                            <arg>-Xplugin:RefasterRuleCompiler</arg>
+                        </compilerArgs>
+                    </configuration>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
+</project>
--- a/workshop/src/main/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment0DeleteEmptyMethod.java
+++ b/workshop/src/main/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment0DeleteEmptyMethod.java
@@ -0,0 +1,33 @@
+package tech.picnic.errorprone.workshop.bugpatterns;
+
+import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
+import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
+
+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.MethodTreeMatcher;
+import com.google.errorprone.matchers.Description;
+import com.sun.source.tree.MethodTree;
+
+/** A {@link BugChecker} that flags empty methods that seemingly can simply be deleted. */
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary = "Empty method can likely be deleted",
+    severity = WARNING,
+    tags = SIMPLIFICATION)
+public final class Assignment0DeleteEmptyMethod extends BugChecker implements MethodTreeMatcher {
+  private static final long serialVersionUID = 1L;
+
+  /** Instantiates a new {@link Assignment0DeleteEmptyMethod} instance. */
+  public Assignment0DeleteEmptyMethod() {}
+
+  @Override
+  public Description matchMethod(MethodTree tree, VisitorState state) {
+    // XXX: Part 1: Ensure that we only delete methods that contain no statements.
+    // XXX: Part 2: Don't delete methods that are annotated with `@Override`.
+
+    return Description.NO_MATCH;
+  }
+}
--- a/workshop/src/main/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment1AssertJIsNullMethod.java
+++ b/workshop/src/main/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment1AssertJIsNullMethod.java
@@ -0,0 +1,61 @@
+package tech.picnic.errorprone.workshop.bugpatterns;
+
+import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
+import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
+import static com.google.errorprone.matchers.Matchers.allOf;
+import static com.google.errorprone.matchers.Matchers.argument;
+import static com.google.errorprone.matchers.Matchers.argumentCount;
+import static com.google.errorprone.matchers.Matchers.instanceMethod;
+import static com.google.errorprone.matchers.Matchers.nullLiteral;
+
+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.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
+import com.sun.source.tree.MethodInvocationTree;
+
+/**
+ * A {@link BugChecker} that flags AssertJ {@code isEqualTo(null)} checks for simplification.
+ *
+ * <p>This bug checker cannot be replaced with a simple Refaster rule, as the Refaster approach
+ * would require that all overloads of {@link org.assertj.core.api.Assert#isEqualTo(Object)} (such
+ * as {@link org.assertj.core.api.AbstractStringAssert#isEqualTo(String)}) are explicitly
+ * enumerated. This bug checker generically matches all such current and future overloads.
+ */
+@BugPattern(
+    summary = "Prefer `.isNull()` over `.isEqualTo(null)`",
+    severity = SUGGESTION,
+    tags = SIMPLIFICATION)
+public final class Assignment1AssertJIsNullMethod extends BugChecker
+    implements MethodInvocationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Matcher<MethodInvocationTree> ASSERT_IS_EQUAL_TO_NULL =
+      allOf(
+          instanceMethod().onDescendantOf("org.assertj.core.api.Assert").named("isEqualTo"),
+          argumentCount(1),
+          argument(0, nullLiteral()));
+
+  /** Instantiates a new {@link Assignment1AssertJIsNullMethod} instance. */
+  public Assignment1AssertJIsNullMethod() {}
+
+  @Override
+  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+    // This statement filters out `MethodInvocation`s that are *not* `assertThat().isEqualTo(null)`
+    // statements.
+    if (!ASSERT_IS_EQUAL_TO_NULL.matches(tree, state)) {
+      return Description.NO_MATCH;
+    }
+
+    SuggestedFix.Builder fix = SuggestedFix.builder();
+
+    // XXX: Using `fix.merge(<some code>);` make sure we rename the method invocation to `isNull`.
+    // See the `SuggestedFixes` class ;).
+
+    tree.getArguments().forEach(arg -> fix.merge(SuggestedFix.delete(arg)));
+
+    return describeMatch(tree, fix.build());
+  }
+}
--- a/workshop/src/main/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment2DropMockitoEq.java
+++ b/workshop/src/main/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment2DropMockitoEq.java
@@ -0,0 +1,56 @@
+package tech.picnic.errorprone.workshop.bugpatterns;
+
+import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
+import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
+import static com.google.errorprone.matchers.Matchers.staticMethod;
+
+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.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.MethodInvocationTree;
+import tech.picnic.errorprone.utils.SourceCode;
+
+/**
+ * A {@link BugChecker} that flags method invocations for which all arguments are wrapped using
+ * {@link org.mockito.Mockito#eq}; this is redundant.
+ */
+@BugPattern(
+    summary = "Don't unnecessarily use Mockito's `eq(...)`",
+    severity = SUGGESTION,
+    tags = SIMPLIFICATION)
+public final class Assignment2DropMockitoEq extends BugChecker
+    implements MethodInvocationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Matcher<ExpressionTree> MOCKITO_EQ_METHOD =
+      staticMethod().onClass("org.mockito.ArgumentMatchers").named("eq");
+
+  /** Instantiates a new {@link Assignment2DropMockitoEq} instance. */
+  public Assignment2DropMockitoEq() {}
+
+  @Override
+  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+    // XXX: Make sure to return `Description.NO_MATCH` if the `tree` doesn't have arguments, or if
+    // the `isEqInvocation` method below returns `false` for at least one of the arguments.
+
+    SuggestedFix.Builder suggestedFix = SuggestedFix.builder();
+    for (ExpressionTree arg : tree.getArguments()) {
+      suggestedFix.replace(
+          arg,
+          SourceCode.treeToString(
+              Iterables.getOnlyElement(((MethodInvocationTree) arg).getArguments()), state));
+    }
+
+    return describeMatch(tree, suggestedFix.build());
+  }
+
+  @SuppressWarnings("UnusedMethod" /* Recommended to use when implementing this assignment. */)
+  private static boolean isEqInvocation(ExpressionTree tree, VisitorState state) {
+    return tree instanceof MethodInvocationTree && MOCKITO_EQ_METHOD.matches(tree, state);
+  }
+}
--- a/workshop/src/main/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment3DropAutowiredConstructorAnnotation.java
+++ b/workshop/src/main/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment3DropAutowiredConstructorAnnotation.java
@@ -0,0 +1,54 @@
+package tech.picnic.errorprone.workshop.bugpatterns;
+
+import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
+import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
+import static com.google.errorprone.matchers.ChildMultiMatcher.MatchType.AT_LEAST_ONE;
+import static com.google.errorprone.matchers.Matchers.annotations;
+import static com.google.errorprone.matchers.Matchers.isType;
+
+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.ClassTreeMatcher;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.MultiMatcher;
+import com.google.errorprone.matchers.MultiMatcher.MultiMatchResult;
+import com.sun.source.tree.AnnotationTree;
+import com.sun.source.tree.ClassTree;
+import com.sun.source.tree.MethodTree;
+import com.sun.source.tree.Tree;
+import java.util.ArrayList;
+import java.util.List;
+import tech.picnic.errorprone.utils.SourceCode;
+
+/** A {@link BugChecker} that flags redundant {@code @Autowired} constructor annotations. */
+@BugPattern(
+    summary = "Omit `@Autowired` on a class' sole constructor, as it is redundant",
+    severity = SUGGESTION,
+    tags = SIMPLIFICATION)
+public final class Assignment3DropAutowiredConstructorAnnotation extends BugChecker
+    implements ClassTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final MultiMatcher<Tree, AnnotationTree> AUTOWIRED_ANNOTATION =
+      annotations(AT_LEAST_ONE, isType("org.springframework.beans.factory.annotation.Autowired"));
+
+  /** Instantiates a new {@link Assignment3DropAutowiredConstructorAnnotation} instance. */
+  public Assignment3DropAutowiredConstructorAnnotation() {}
+
+  @Override
+  public Description matchClass(ClassTree tree, VisitorState state) {
+    // XXX: Using the `ASTHelpers#getConstructors` method, return `Description.NO_MATCH` if we do
+    // not have exactly 1 constructor (start by dropping `new ArrayList<>()` on the next line).
+    List<MethodTree> constructors = new ArrayList<>();
+
+    MultiMatchResult<AnnotationTree> hasAutowiredAnnotation =
+        AUTOWIRED_ANNOTATION.multiMatchResult(Iterables.getOnlyElement(constructors), state);
+    if (!hasAutowiredAnnotation.matches()) {
+      return Description.NO_MATCH;
+    }
+
+    AnnotationTree annotation = hasAutowiredAnnotation.onlyMatchingNode();
+    return describeMatch(annotation, SourceCode.deleteWithTrailingWhitespace(annotation, state));
+  }
+}
--- a/workshop/src/main/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment4JUnitTestMethodDeclaration.java
+++ b/workshop/src/main/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment4JUnitTestMethodDeclaration.java
@@ -0,0 +1,61 @@
+package tech.picnic.errorprone.workshop.bugpatterns;
+
+import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
+import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
+import static com.google.errorprone.matchers.ChildMultiMatcher.MatchType.AT_LEAST_ONE;
+import static com.google.errorprone.matchers.Matchers.annotations;
+import static com.google.errorprone.matchers.Matchers.anyOf;
+import static com.google.errorprone.matchers.Matchers.isType;
+
+import com.google.auto.service.AutoService;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Sets;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.MethodTreeMatcher;
+import com.google.errorprone.fixes.SuggestedFix;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.MultiMatcher;
+import com.sun.source.tree.AnnotationTree;
+import com.sun.source.tree.MethodTree;
+import javax.lang.model.element.Modifier;
+
+/** A {@link BugChecker} that flags non-canonical JUnit method declarations. */
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary = "JUnit method declaration can likely be improved",
+    severity = WARNING,
+    tags = SIMPLIFICATION)
+@SuppressWarnings({
+  "UnusedMethod",
+  "UnusedVariable"
+} /* This check is yet to be implemented as part of the demo. */)
+public final class Assignment4JUnitTestMethodDeclaration extends BugChecker
+    implements MethodTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final ImmutableSet<Modifier> ILLEGAL_MODIFIERS =
+      Sets.immutableEnumSet(Modifier.PRIVATE, Modifier.PROTECTED, Modifier.PUBLIC);
+  private static final MultiMatcher<MethodTree, AnnotationTree> TEST_METHOD =
+      annotations(AT_LEAST_ONE, anyOf(isType("org.junit.jupiter.api.Test")));
+
+  /** Instantiates a new {@link Assignment4JUnitTestMethodDeclaration} instance. */
+  public Assignment4JUnitTestMethodDeclaration() {}
+
+  @Override
+  public Description matchMethod(MethodTree tree, VisitorState state) {
+    // XXX: Part 1: Return `Description.NO_MATCH` if the method is not a `TEST_METHOD`.
+
+    SuggestedFix.Builder fixBuilder = SuggestedFix.builder();
+
+    // XXX: Part 2: Make sure that JUnit test methods don't use any of the modifiers from the
+    // `ILLEGAL_MODIFIERS` field, by using `SuggestedFixes#removeModifiers` and
+    // `SuggestedFix.Builder#merge`.
+
+    if (fixBuilder.isEmpty()) {
+      return Description.NO_MATCH;
+    }
+
+    return describeMatch(tree, fixBuilder.build());
+  }
+}
--- a/workshop/src/main/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment5DeleteIdentityConversion.java
+++ b/workshop/src/main/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment5DeleteIdentityConversion.java
@@ -0,0 +1,108 @@
+package tech.picnic.errorprone.workshop.bugpatterns;
+
+import static com.google.common.collect.ImmutableSet.toImmutableSet;
+import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
+import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
+import static com.google.errorprone.matchers.Matchers.anyOf;
+import static com.google.errorprone.matchers.Matchers.staticMethod;
+import static com.google.errorprone.suppliers.Suppliers.OBJECT_TYPE;
+
+import com.google.common.primitives.Primitives;
+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.bugpatterns.TypesWithUndefinedEquality;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
+import com.google.errorprone.util.ASTHelpers;
+import com.google.errorprone.util.ASTHelpers.TargetType;
+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 com.sun.tools.javac.code.Types;
+import java.util.Arrays;
+import java.util.List;
+
+/** A {@link BugChecker} that flags redundant identity conversions. */
+@BugPattern(
+    summary = "Avoid or clarify identity conversions",
+    severity = WARNING,
+    tags = SIMPLIFICATION)
+public final class Assignment5DeleteIdentityConversion extends BugChecker
+    implements MethodInvocationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Matcher<ExpressionTree> IS_CONVERSION_METHOD =
+      anyOf(
+          staticMethod()
+              .onClassAny(
+                  Primitives.allWrapperTypes().stream()
+                      .map(Class::getName)
+                      .collect(toImmutableSet()))
+              .named("valueOf"),
+          staticMethod().onClass(String.class.getName()).named("valueOf"),
+          staticMethod()
+              .onClassAny(
+                  "com.google.common.collect.ImmutableBiMap",
+                  "com.google.common.collect.ImmutableList",
+                  "com.google.common.collect.ImmutableListMultimap",
+                  "com.google.common.collect.ImmutableMap",
+                  "com.google.common.collect.ImmutableMultimap",
+                  "com.google.common.collect.ImmutableMultiset",
+                  "com.google.common.collect.ImmutableRangeMap",
+                  "com.google.common.collect.ImmutableRangeSet",
+                  "com.google.common.collect.ImmutableSet",
+                  "com.google.common.collect.ImmutableSetMultimap",
+                  "com.google.common.collect.ImmutableTable")
+              .named("copyOf"),
+          staticMethod()
+              .onClass("com.google.errorprone.matchers.Matchers")
+              .namedAnyOf("allOf", "anyOf"));
+
+  /** Instantiates a new {@link Assignment5DeleteIdentityConversion} instance. */
+  public Assignment5DeleteIdentityConversion() {}
+
+  @Override
+  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+    List<? extends ExpressionTree> arguments = tree.getArguments();
+    // XXX: Make sure we skip invocations that do not pass exactly one argument, by using the
+    // `tree`.
+    if (!IS_CONVERSION_METHOD.matches(tree, state)) {
+      return Description.NO_MATCH;
+    }
+
+    ExpressionTree sourceTree = arguments.get(0);
+    Type sourceType = ASTHelpers.getType(sourceTree);
+    Type resultType = ASTHelpers.getType(tree);
+    TargetType targetType = ASTHelpers.targetType(state);
+    if (sourceType == null || resultType == null || targetType == null) {
+      return Description.NO_MATCH;
+    }
+
+    if (!state.getTypes().isSameType(sourceType, resultType)
+        && !isConvertibleWithWellDefinedEquality(sourceType, targetType.type(), state)) {
+      return Description.NO_MATCH;
+    }
+
+    if (sourceType.isPrimitive()
+        && state.getPath().getParentPath().getLeaf() instanceof MemberSelectTree) {
+      return Description.NO_MATCH;
+    }
+
+    return buildDescription(tree)
+        // XXX: Use the `.addFix()` to suggest replacing the original `tree` with the `sourceTree`.
+        // Tip: You can get the actual String representation of a Tree by using the
+        // `SourceCode#treeToString`.
+        .build();
+  }
+
+  private static boolean isConvertibleWithWellDefinedEquality(
+      Type sourceType, Type targetType, VisitorState state) {
+    Types types = state.getTypes();
+    return !types.isSameType(targetType, OBJECT_TYPE.get(state))
+        && types.isConvertible(sourceType, targetType)
+        && Arrays.stream(TypesWithUndefinedEquality.values())
+            .noneMatch(b -> b.matchesType(sourceType, state) || b.matchesType(targetType, state));
+  }
+}
--- a/workshop/src/main/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment0Rules.java
+++ b/workshop/src/main/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment0Rules.java
@@ -0,0 +1,22 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import com.google.errorprone.refaster.annotation.AfterTemplate;
+import com.google.errorprone.refaster.annotation.BeforeTemplate;
+
+/** Refaster rule used as example for the assignments of the workshop. */
+final class WorkshopAssignment0Rules {
+  private WorkshopAssignment0Rules() {}
+
+  /** Prefer {@link String#isEmpty()} over alternatives that consult the string's length. */
+  static final class ExampleStringIsEmpty {
+    @BeforeTemplate
+    static boolean before(String string) {
+      return string.length() == 0;
+    }
+
+    @AfterTemplate
+    static boolean after(String string) {
+      return string.isEmpty();
+    }
+  }
+}
--- a/workshop/src/main/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment1Rules.java
+++ b/workshop/src/main/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment1Rules.java
@@ -0,0 +1,11 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+/** Refaster rules for the first assignment of the workshop. */
+final class WorkshopAssignment1Rules {
+  private WorkshopAssignment1Rules() {}
+
+  /** Prefer {@link String#String(char[])} over {@link String#copyValueOf(char[])}. */
+  static final class NewStringCharArray {
+    // XXX: Implement this Refaster rule.
+  }
+}
--- a/workshop/src/main/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment2Rules.java
+++ b/workshop/src/main/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment2Rules.java
@@ -0,0 +1,34 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import com.google.common.collect.ImmutableList;
+import com.google.errorprone.refaster.Refaster;
+import com.google.errorprone.refaster.annotation.AfterTemplate;
+import com.google.errorprone.refaster.annotation.BeforeTemplate;
+
+import java.util.Collections;
+import java.util.List;
+
+/** Refaster rules for the second assignment of the workshop. */
+final class WorkshopAssignment2Rules {
+  private WorkshopAssignment2Rules() {}
+
+  /**
+   * Prefer {@link ImmutableList#of(Object)} over alternatives that don't communicate the
+   * immutability of the resulting list at the type level.
+   */
+  static final class ImmutableListOfOne<T> {
+    @BeforeTemplate
+    static <T> List<T> before(T t) {
+      return ImmutableList.copyOf(
+          Refaster.anyOf(
+              Collections.singletonList(t),
+              List.of(t))
+      );
+    }
+
+    @AfterTemplate
+    static <T> List<T> after(T t) {
+      return ImmutableList.of(t);
+    }
+  }
+}
--- a/workshop/src/main/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment3Rules.java
+++ b/workshop/src/main/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment3Rules.java
@@ -0,0 +1,21 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import com.google.common.base.Preconditions;
+
+/** Refaster rules for the third assignment of the workshop. */
+@SuppressWarnings("UnusedTypeParameter" /* Ignore this for demo purposes. */)
+final class WorkshopAssignment3Rules {
+  private WorkshopAssignment3Rules() {}
+
+  // XXX: Tip: check the input and output files to see the *expected* refactoring.
+
+  /** Prefer {@link Preconditions#checkArgument(boolean)} over if statements. */
+  static final class CheckArgumentWithoutMessage {
+    // XXX: Implement the Refaster rule to get the test green.
+  }
+
+  /** Prefer {@link Preconditions#checkArgument(boolean, Object)} over if statements. */
+  static final class CheckArgumentWithMessage {
+    // XXX: Implement the Refaster rule to get the test green.
+  }
+}
--- a/workshop/src/main/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment4Rules.java
+++ b/workshop/src/main/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment4Rules.java
@@ -0,0 +1,25 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+/** Refaster rules for the fourth assignment of the workshop. */
+@SuppressWarnings("java:S1698" /* Reference comparison is valid for enums. */)
+final class WorkshopAssignment4Rules {
+  private WorkshopAssignment4Rules() {}
+
+  // The test fails because non Enum comparisons are also rewritten.
+  // Fix the test by tweaking the type parameters.
+
+  // XXX: Get the test to pass by improving the Refaster rule (uncommented it first).
+
+  //  static final class PrimitiveOrReferenceEqualityEnum<T> {
+  //    @BeforeTemplate
+  //    boolean before(T a, T b) {
+  //      return Refaster.anyOf(a.equals(b), Objects.equals(a, b));
+  //    }
+  //
+  //    @AfterTemplate
+  //    @AlsoNegation
+  //    boolean after(T a, T b) {
+  //      return a == b;
+  //    }
+  //  }
+}
--- a/workshop/src/main/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment5Rules.java
+++ b/workshop/src/main/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment5Rules.java
@@ -0,0 +1,12 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+/** Refaster rules for the fifth assignment of the workshop. */
+@SuppressWarnings("UnusedTypeParameter" /* Ignore this for demo purposes. */)
+final class WorkshopAssignment5Rules {
+  private WorkshopAssignment5Rules() {}
+
+  abstract static class StreamDoAllMatch<T> {
+    // XXX: Implement the Refaster rule to get the test green.
+    // Tip: use the `@Placeholder` annotation.
+  }
+}
--- a/workshop/src/test/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment0Assignment0DeleteEmptyMethodTest.java
+++ b/workshop/src/test/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment0Assignment0DeleteEmptyMethodTest.java
@@ -0,0 +1,70 @@
+package tech.picnic.errorprone.workshop.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+@Disabled("Enable this when implementing the BugChecker.")
+final class Assignment0Assignment0DeleteEmptyMethodTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(Assignment0DeleteEmptyMethod.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "class A {",
+            "  Object m1() {",
+            "    return null;",
+            "  }",
+            "",
+            "  void m2() {",
+            "    System.out.println(42);",
+            "  }",
+            "",
+            "  // BUG: Diagnostic contains:",
+            "  static void m3() {}",
+            "",
+            "  interface F {",
+            "    void fun();",
+            "  }",
+            "}")
+        .addSourceLines(
+            "B.java",
+            "final class B implements A.F {",
+            "  @Override",
+            "  public void fun() {}",
+            "",
+            "  /** Javadoc. */",
+            "  // BUG: Diagnostic contains:",
+            "  void m4() {}",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    BugCheckerRefactoringTestHelper.newInstance(Assignment0DeleteEmptyMethod.class, getClass())
+        .addInputLines(
+            "A.java",
+            "final class A {",
+            "",
+            "  void instanceMethod() {}",
+            "",
+            "  static void staticMethod() {}",
+            "",
+            "  static void staticMethodWithComment() {",
+            "    System.out.println(42);",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "final class A {",
+            "",
+            "  static void staticMethodWithComment() {",
+            "    System.out.println(42);",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}
--- a/workshop/src/test/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment1AssertJIsNullMethodTest.java
+++ b/workshop/src/test/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment1AssertJIsNullMethodTest.java
@@ -0,0 +1,60 @@
+package tech.picnic.errorprone.workshop.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+@Disabled("Enable this when implementing the BugChecker.")
+final class Assignment1AssertJIsNullMethodTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(Assignment1AssertJIsNullMethod.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import static org.assertj.core.api.Assertions.assertThat;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    assertThat(1).isEqualTo(1);",
+            "    // BUG: Diagnostic contains:",
+            "    assertThat(1).isEqualTo(null);",
+            "    // BUG: Diagnostic contains:",
+            "    assertThat(\"foo\").isEqualTo(null);",
+            "    isEqualTo(null);",
+            "  }",
+            "",
+            "  private boolean isEqualTo(Object value) {",
+            "    return value.equals(\"bar\");",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    BugCheckerRefactoringTestHelper.newInstance(Assignment1AssertJIsNullMethod.class, getClass())
+        .addInputLines(
+            "A.java",
+            "import static org.assertj.core.api.Assertions.assertThat;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    assertThat(1).isEqualTo(null);",
+            "    assertThat(\"foo\").isEqualTo(null);",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import static org.assertj.core.api.Assertions.assertThat;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    assertThat(1).isNull();",
+            "    assertThat(\"foo\").isNull();",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}
--- a/workshop/src/test/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment2DropMockitoEqTest.java
+++ b/workshop/src/test/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment2DropMockitoEqTest.java
@@ -0,0 +1,102 @@
+package tech.picnic.errorprone.workshop.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+@Disabled("Enable this when implementing the BugChecker.")
+final class Assignment2DropMockitoEqTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(Assignment2DropMockitoEq.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import static org.mockito.ArgumentMatchers.eq;",
+            "import static org.mockito.ArgumentMatchers.notNull;",
+            "import static org.mockito.Mockito.doAnswer;",
+            "import static org.mockito.Mockito.mock;",
+            "",
+            "import java.util.function.BiConsumer;",
+            "import java.util.function.Consumer;",
+            "import org.mockito.ArgumentMatchers;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Runnable runnable = mock(Runnable.class);",
+            "    doAnswer(inv -> null).when(runnable).run();",
+            "",
+            "    Consumer<String> consumer = mock(Consumer.class);",
+            "    doAnswer(inv -> null).when(consumer).accept(\"foo\");",
+            "    doAnswer(inv -> null).when(consumer).accept(notNull());",
+            "    // BUG: Diagnostic contains:",
+            "    doAnswer(inv -> null).when(consumer).accept(ArgumentMatchers.eq(\"foo\"));",
+            "    // BUG: Diagnostic contains:",
+            "    doAnswer(inv -> null).when(consumer).accept(eq(toString()));",
+            "",
+            "    BiConsumer<Integer, String> biConsumer = mock(BiConsumer.class);",
+            "    doAnswer(inv -> null).when(biConsumer).accept(0, \"foo\");",
+            "    doAnswer(inv -> null).when(biConsumer).accept(eq(0), notNull());",
+            "    doAnswer(inv -> null).when(biConsumer).accept(notNull(), eq(\"foo\"));",
+            "    doAnswer(inv -> null)",
+            "        .when(biConsumer)",
+            "        // BUG: Diagnostic contains:",
+            "        .accept(ArgumentMatchers.eq(0), ArgumentMatchers.eq(\"foo\"));",
+            "    // BUG: Diagnostic contains:",
+            "    doAnswer(inv -> null).when(biConsumer).accept(eq(hashCode()), eq(toString()));",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    BugCheckerRefactoringTestHelper.newInstance(Assignment2DropMockitoEq.class, getClass())
+        .addInputLines(
+            "A.java",
+            "import static org.mockito.ArgumentMatchers.eq;",
+            "import static org.mockito.Mockito.doAnswer;",
+            "import static org.mockito.Mockito.mock;",
+            "",
+            "import java.util.function.BiConsumer;",
+            "import java.util.function.Consumer;",
+            "import org.mockito.ArgumentMatchers;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Consumer<String> consumer = mock(Consumer.class);",
+            "    doAnswer(inv -> null).when(consumer).accept(ArgumentMatchers.eq(\"foo\"));",
+            "    doAnswer(inv -> null).when(consumer).accept(eq(toString()));",
+            "",
+            "    BiConsumer<Integer, String> biConsumer = mock(BiConsumer.class);",
+            "    doAnswer(inv -> null)",
+            "        .when(biConsumer)",
+            "        .accept(ArgumentMatchers.eq(0), ArgumentMatchers.eq(\"foo\"));",
+            "    doAnswer(inv -> null).when(biConsumer).accept(eq(hashCode()), eq(toString()));",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import static org.mockito.ArgumentMatchers.eq;",
+            "import static org.mockito.Mockito.doAnswer;",
+            "import static org.mockito.Mockito.mock;",
+            "",
+            "import java.util.function.BiConsumer;",
+            "import java.util.function.Consumer;",
+            "import org.mockito.ArgumentMatchers;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Consumer<String> consumer = mock(Consumer.class);",
+            "    doAnswer(inv -> null).when(consumer).accept(\"foo\");",
+            "    doAnswer(inv -> null).when(consumer).accept(toString());",
+            "",
+            "    BiConsumer<Integer, String> biConsumer = mock(BiConsumer.class);",
+            "    doAnswer(inv -> null).when(biConsumer).accept(0, \"foo\");",
+            "    doAnswer(inv -> null).when(biConsumer).accept(hashCode(), toString());",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}
--- a/workshop/src/test/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment3DropAutowiredConstructorAnnotationTest.java
+++ b/workshop/src/test/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment3DropAutowiredConstructorAnnotationTest.java
@@ -0,0 +1,106 @@
+package tech.picnic.errorprone.workshop.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+@Disabled("Enable this when implementing the BugChecker.")
+final class Assignment3DropAutowiredConstructorAnnotationTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(
+            Assignment3DropAutowiredConstructorAnnotation.class, getClass())
+        .addSourceLines(
+            "Container.java",
+            "import com.google.errorprone.annotations.Immutable;",
+            "import java.util.List;",
+            "import org.springframework.beans.factory.annotation.Autowired;",
+            "",
+            "interface Container {",
+            "  @Immutable",
+            "  class A {",
+            "    A() {}",
+            "  }",
+            "",
+            "  class B {",
+            "    @Autowired",
+            "    void setProperty(Object o) {}",
+            "  }",
+            "",
+            "  class C {",
+            "    // BUG: Diagnostic contains:",
+            "    @Autowired",
+            "    C() {}",
+            "  }",
+            "",
+            "  class D {",
+            "    // BUG: Diagnostic contains:",
+            "    @Autowired",
+            "    D(String x) {}",
+            "  }",
+            "",
+            "  class E {",
+            "    @Autowired",
+            "    E() {}",
+            "",
+            "    E(String x) {}",
+            "  }",
+            "",
+            "  class F {",
+            "    F() {}",
+            "",
+            "    @Autowired",
+            "    F(String x) {}",
+            "  }",
+            "",
+            "  class G {",
+            "    @Autowired private Object o;",
+            "  }",
+            "",
+            "  class H {",
+            "    @SafeVarargs",
+            "    H(List<String>... lists) {}",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    BugCheckerRefactoringTestHelper.newInstance(
+            Assignment3DropAutowiredConstructorAnnotation.class, getClass())
+        .addInputLines(
+            "Container.java",
+            "import org.springframework.beans.factory.annotation.Autowired;",
+            "",
+            "interface Container {",
+            "  class A {",
+            "    @Autowired",
+            "    @Deprecated",
+            "    A() {}",
+            "  }",
+            "",
+            "  class B {",
+            "    @Autowired",
+            "    B(String x) {}",
+            "  }",
+            "}")
+        .addOutputLines(
+            "Container.java",
+            "import org.springframework.beans.factory.annotation.Autowired;",
+            "",
+            "interface Container {",
+            "  class A {",
+            "    @Deprecated",
+            "    A() {}",
+            "  }",
+            "",
+            "  class B {",
+            "    B(String x) {}",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}
--- a/workshop/src/test/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment4JUnitTestMethodDeclarationTest.java
+++ b/workshop/src/test/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment4JUnitTestMethodDeclarationTest.java
@@ -0,0 +1,91 @@
+package tech.picnic.errorprone.workshop.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+@Disabled("Enable this to validate part 1.")
+final class Assignment4JUnitTestMethodDeclarationTest {
+  @Test
+  void identificationIllegalModifiers() {
+    CompilationTestHelper.newInstance(Assignment4JUnitTestMethodDeclaration.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import org.junit.jupiter.api.Test;",
+            "",
+            "class A {",
+            "  @Test",
+            "  void method1() {}",
+            "",
+            "  @Test",
+            "  // BUG: Diagnostic contains:",
+            "  public void method2() {}",
+            "",
+            "  @Test",
+            "  // BUG: Diagnostic contains:",
+            "  protected void method3() {}",
+            "",
+            "  @Test",
+            "  // BUG: Diagnostic contains:",
+            "  private void method4() {}",
+            "",
+            "  public void method5() {}",
+            "",
+            "  protected void method6() {}",
+            "",
+            "  private void method7() {}",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacementIllegalModifiers() {
+    BugCheckerRefactoringTestHelper.newInstance(
+            Assignment4JUnitTestMethodDeclaration.class, getClass())
+        .addInputLines(
+            "A.java",
+            "import org.junit.jupiter.api.Test;",
+            "",
+            "class A {",
+            "  @Test",
+            "  void foo() {}",
+            "",
+            "  @Test",
+            "  public void bar() {}",
+            "",
+            "  @Test",
+            "  protected void baz() {}",
+            "",
+            "  @Test",
+            "  private void qux() {}",
+            "",
+            "  public void quux() {}",
+            "",
+            "  private void quuz() {}",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import org.junit.jupiter.api.Test;",
+            "",
+            "class A {",
+            "  @Test",
+            "  void foo() {}",
+            "",
+            "  @Test",
+            "  void bar() {}",
+            "",
+            "  @Test",
+            "  void baz() {}",
+            "",
+            "  @Test",
+            "  void qux() {}",
+            "",
+            "  public void quux() {}",
+            "",
+            "  private void quuz() {}",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}
--- a/workshop/src/test/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment5DeleteIdentityConversionTest.java
+++ b/workshop/src/test/java/tech/picnic/errorprone/workshop/bugpatterns/Assignment5DeleteIdentityConversionTest.java
@@ -0,0 +1,223 @@
+package tech.picnic.errorprone.workshop.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+@Disabled("Enable this when implementing the BugChecker.")
+final class Assignment5DeleteIdentityConversionTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(Assignment5DeleteIdentityConversion.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import static com.google.errorprone.matchers.Matchers.instanceMethod;",
+            "import static com.google.errorprone.matchers.Matchers.staticMethod;",
+            "",
+            "import com.google.common.collect.ImmutableBiMap;",
+            "import com.google.common.collect.ImmutableList;",
+            "import com.google.common.collect.ImmutableListMultimap;",
+            "import com.google.common.collect.ImmutableMap;",
+            "import com.google.common.collect.ImmutableMultimap;",
+            "import com.google.common.collect.ImmutableMultiset;",
+            "import com.google.common.collect.ImmutableRangeMap;",
+            "import com.google.common.collect.ImmutableRangeSet;",
+            "import com.google.common.collect.ImmutableSet;",
+            "import com.google.common.collect.ImmutableSetMultimap;",
+            "import com.google.common.collect.ImmutableTable;",
+            "import com.google.errorprone.matchers.Matcher;",
+            "import com.google.errorprone.matchers.Matchers;",
+            "",
+            "public final class A {",
+            "  public void m() {",
+            "    // BUG: Diagnostic contains:",
+            "    Matcher allOf1 = Matchers.allOf(instanceMethod());",
+            "    Matcher allOf2 = Matchers.allOf(instanceMethod(), staticMethod());",
+            "    // BUG: Diagnostic contains:",
+            "    Matcher anyOf1 = Matchers.anyOf(staticMethod());",
+            "    Matcher anyOf2 = Matchers.anyOf(instanceMethod(), staticMethod());",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    Boolean b1 = Boolean.valueOf(Boolean.FALSE);",
+            "    // BUG: Diagnostic contains:",
+            "    Boolean b2 = Boolean.valueOf(false);",
+            "    // BUG: Diagnostic contains:",
+            "    boolean b3 = Boolean.valueOf(Boolean.FALSE);",
+            "    // BUG: Diagnostic contains:",
+            "    boolean b4 = Boolean.valueOf(false);",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    Byte byte1 = Byte.valueOf((Byte) Byte.MIN_VALUE);",
+            "    // BUG: Diagnostic contains:",
+            "    Byte byte2 = Byte.valueOf(Byte.MIN_VALUE);",
+            "    // BUG: Diagnostic contains:",
+            "    byte byte3 = Byte.valueOf((Byte) Byte.MIN_VALUE);",
+            "    // BUG: Diagnostic contains:",
+            "    byte byte4 = Byte.valueOf(Byte.MIN_VALUE);",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    Character c1 = Character.valueOf((Character) 'a');",
+            "    // BUG: Diagnostic contains:",
+            "    Character c2 = Character.valueOf('a');",
+            "    // BUG: Diagnostic contains:",
+            "    char c3 = Character.valueOf((Character) 'a');",
+            "    // BUG: Diagnostic contains:",
+            "    char c4 = Character.valueOf('a');",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    Double d1 = Double.valueOf((Double) 0.0);",
+            "    // BUG: Diagnostic contains:",
+            "    Double d2 = Double.valueOf(0.0);",
+            "    // BUG: Diagnostic contains:",
+            "    double d3 = Double.valueOf((Double) 0.0);",
+            "    // BUG: Diagnostic contains:",
+            "    double d4 = Double.valueOf(0.0);",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    Float f1 = Float.valueOf((Float) 0.0F);",
+            "    // BUG: Diagnostic contains:",
+            "    Float f2 = Float.valueOf(0.0F);",
+            "    // BUG: Diagnostic contains:",
+            "    float f3 = Float.valueOf((Float) 0.0F);",
+            "    // BUG: Diagnostic contains:",
+            "    float f4 = Float.valueOf(0.0F);",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    Integer i1 = Integer.valueOf((Integer) 1);",
+            "    // BUG: Diagnostic contains:",
+            "    Integer i2 = Integer.valueOf(1);",
+            "    // BUG: Diagnostic contains:",
+            "    int i3 = Integer.valueOf((Integer) 1);",
+            "    // BUG: Diagnostic contains:",
+            "    int i4 = Integer.valueOf(1);",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    Long l1 = Long.valueOf((Long) 1L);",
+            "    // BUG: Diagnostic contains:",
+            "    Long l2 = Long.valueOf(1L);",
+            "    // BUG: Diagnostic contains:",
+            "    long l3 = Long.valueOf((Long) 1L);",
+            "    // BUG: Diagnostic contains:",
+            "    long l4 = Long.valueOf(1L);",
+            "",
+            "    Long l5 = Long.valueOf((Integer) 1);",
+            "    Long l6 = Long.valueOf(1);",
+            "    // BUG: Diagnostic contains:",
+            "    long l7 = Long.valueOf((Integer) 1);",
+            "    // BUG: Diagnostic contains:",
+            "    long l8 = Long.valueOf(1);",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    Short s1 = Short.valueOf((Short) Short.MIN_VALUE);",
+            "    // BUG: Diagnostic contains:",
+            "    Short s2 = Short.valueOf(Short.MIN_VALUE);",
+            "    // BUG: Diagnostic contains:",
+            "    short s3 = Short.valueOf((Short) Short.MIN_VALUE);",
+            "    // BUG: Diagnostic contains:",
+            "    short s4 = Short.valueOf(Short.MIN_VALUE);",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    String boolStr = Boolean.valueOf(Boolean.FALSE).toString();",
+            "    int boolHash = Boolean.valueOf(false).hashCode();",
+            "    // BUG: Diagnostic contains:",
+            "    int byteHash = Byte.valueOf((Byte) Byte.MIN_VALUE).hashCode();",
+            "    String byteStr = Byte.valueOf(Byte.MIN_VALUE).toString();",
+            "",
+            "    String str1 = String.valueOf(0);",
+            "    // BUG: Diagnostic contains:",
+            "    String str2 = String.valueOf(\"1\");",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    ImmutableBiMap<Object, Object> o1 = ImmutableBiMap.copyOf(ImmutableBiMap.of());",
+            "    // BUG: Diagnostic contains:",
+            "    ImmutableList<Object> o2 = ImmutableList.copyOf(ImmutableList.of());",
+            "    ImmutableListMultimap<Object, Object> o3 =",
+            "        // BUG: Diagnostic contains:",
+            "        ImmutableListMultimap.copyOf(ImmutableListMultimap.of());",
+            "    // BUG: Diagnostic contains:",
+            "    ImmutableMap<Object, Object> o4 = ImmutableMap.copyOf(ImmutableMap.of());",
+            "    // BUG: Diagnostic contains:",
+            "    ImmutableMultimap<Object, Object> o5 = ImmutableMultimap.copyOf(ImmutableMultimap.of());",
+            "    // BUG: Diagnostic contains:",
+            "    ImmutableMultiset<Object> o6 = ImmutableMultiset.copyOf(ImmutableMultiset.of());",
+            "    // BUG: Diagnostic contains:",
+            "    ImmutableRangeMap<String, Object> o7 = ImmutableRangeMap.copyOf(ImmutableRangeMap.of());",
+            "    // BUG: Diagnostic contains:",
+            "    ImmutableRangeSet<String> o8 = ImmutableRangeSet.copyOf(ImmutableRangeSet.of());",
+            "    // BUG: Diagnostic contains:",
+            "    ImmutableSet<Object> o9 = ImmutableSet.copyOf(ImmutableSet.of());",
+            "    ImmutableSetMultimap<Object, Object> o10 =",
+            "        // BUG: Diagnostic contains:",
+            "        ImmutableSetMultimap.copyOf(ImmutableSetMultimap.of());",
+            "    // BUG: Diagnostic contains:",
+            "    ImmutableTable<Object, Object, Object> o11 = ImmutableTable.copyOf(ImmutableTable.of());",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    BugCheckerRefactoringTestHelper.newInstance(
+            Assignment5DeleteIdentityConversion.class, getClass())
+        .addInputLines(
+            "A.java",
+            "import static com.google.errorprone.matchers.Matchers.staticMethod;",
+            "import static org.mockito.Mockito.when;",
+            "",
+            "import com.google.common.collect.ImmutableCollection;",
+            "import com.google.common.collect.ImmutableList;",
+            "import com.google.common.collect.ImmutableSet;",
+            "import java.util.ArrayList;",
+            "import java.util.Collection;",
+            "",
+            "public final class A {",
+            "  public void m() {",
+            "    ImmutableSet<Object> set1 = ImmutableSet.copyOf(ImmutableSet.of());",
+            "    ImmutableSet<Object> set2 = ImmutableSet.copyOf(ImmutableList.of());",
+            "",
+            "    ImmutableCollection<Integer> list1 = ImmutableList.copyOf(ImmutableList.of(1));",
+            "    ImmutableCollection<Integer> list2 = ImmutableList.copyOf(new ArrayList<>(ImmutableList.of(1)));",
+            "",
+            "    Collection<Integer> c1 = ImmutableSet.copyOf(ImmutableSet.of(1));",
+            "    Collection<Integer> c2 = ImmutableList.copyOf(new ArrayList<>(ImmutableList.of(1)));",
+            "",
+            "    Object o1 = ImmutableSet.copyOf(ImmutableList.of());",
+            "    Object o2 = ImmutableSet.copyOf(ImmutableSet.of());",
+            "",
+            "    when(\"foo\".contains(\"f\")).thenAnswer(inv -> ImmutableSet.copyOf(ImmutableList.of(1)));",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import static com.google.errorprone.matchers.Matchers.staticMethod;",
+            "import static org.mockito.Mockito.when;",
+            "",
+            "import com.google.common.collect.ImmutableCollection;",
+            "import com.google.common.collect.ImmutableList;",
+            "import com.google.common.collect.ImmutableSet;",
+            "import java.util.ArrayList;",
+            "import java.util.Collection;",
+            "",
+            "public final class A {",
+            "  public void m() {",
+            "    ImmutableSet<Object> set1 = ImmutableSet.of();",
+            "    ImmutableSet<Object> set2 = ImmutableSet.copyOf(ImmutableList.of());",
+            "",
+            "    ImmutableCollection<Integer> list1 = ImmutableList.of(1);",
+            "    ImmutableCollection<Integer> list2 = ImmutableList.copyOf(new ArrayList<>(ImmutableList.of(1)));",
+            "",
+            "    Collection<Integer> c1 = ImmutableSet.of(1);",
+            "    Collection<Integer> c2 = ImmutableList.copyOf(new ArrayList<>(ImmutableList.of(1)));",
+            "",
+            "    Object o1 = ImmutableSet.copyOf(ImmutableList.of());",
+            "    Object o2 = ImmutableSet.of();",
+            "",
+            "    when(\"foo\".contains(\"f\")).thenAnswer(inv -> ImmutableSet.copyOf(ImmutableList.of(1)));",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}
--- a/workshop/src/test/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopRefasterRulesTest.java
+++ b/workshop/src/test/java/tech/picnic/errorprone/workshop/refasterrules/WorkshopRefasterRulesTest.java
@@ -0,0 +1,37 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollection;
+
+final class WorkshopRefasterRulesTest {
+  @Test
+  void validateExampleRuleCollection() {
+    RefasterRuleCollection.validate(WorkshopAssignment0Rules.class);
+  }
+
+  @Test
+  void validateFirstWorkshopAssignment() {
+    RefasterRuleCollection.validate(WorkshopAssignment1Rules.class);
+  }
+
+  @Test
+  void validateSecondWorkshopAssignment() {
+    RefasterRuleCollection.validate(WorkshopAssignment2Rules.class);
+  }
+
+  @Test
+  void validateThirdWorkshopAssignment() {
+    RefasterRuleCollection.validate(WorkshopAssignment3Rules.class);
+  }
+
+  @Test
+  void validateFourthWorkshopAssignment() {
+    RefasterRuleCollection.validate(WorkshopAssignment4Rules.class);
+  }
+
+  @Test
+  void validateFifthWorkshopAssignment() {
+    RefasterRuleCollection.validate(WorkshopAssignment5Rules.class);
+  }
+}
--- a/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment0RulesTestInput.java
+++ b/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment0RulesTestInput.java
@@ -0,0 +1,10 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class WorkshopAssignment0RulesTest implements RefasterRuleCollectionTestCase {
+  boolean testExampleStringIsEmpty() {
+    boolean b = "foo".length() == 0;
+    return "bar".length() == 0;
+  }
+}
--- a/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment0RulesTestOutput.java
+++ b/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment0RulesTestOutput.java
@@ -0,0 +1,10 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class WorkshopAssignment0RulesTest implements RefasterRuleCollectionTestCase {
+  boolean testExampleStringIsEmpty() {
+    boolean b = "foo".isEmpty();
+    return "bar".isEmpty();
+  }
+}
--- a/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment1RulesTestInput.java
+++ b/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment1RulesTestInput.java
@@ -0,0 +1,11 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class WorkshopAssignment1RulesTest implements RefasterRuleCollectionTestCase {
+  String testNewStringCharArray() {
+    String.copyValueOf(new char[] {});
+    String.copyValueOf(new char[] {'f', 'o', 'o'});
+    return String.copyValueOf(new char[] {'b', 'a', 'r'});
+  }
+}
--- a/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment1RulesTestOutput.java
+++ b/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment1RulesTestOutput.java
@@ -0,0 +1,11 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class WorkshopAssignment1RulesTest implements RefasterRuleCollectionTestCase {
+  String testNewStringCharArray() {
+    new String(new char[] {});
+    new String(new char[] {'f', 'o', 'o'});
+    return new String(new char[] {'b', 'a', 'r'});
+  }
+}
--- a/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment2RulesTestInput.java
+++ b/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment2RulesTestInput.java
@@ -0,0 +1,20 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import com.google.common.collect.ImmutableSet;
+import java.util.Collections;
+import java.util.List;
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class WorkshopAssignment2RulesTest implements RefasterRuleCollectionTestCase {
+  @Override
+  public ImmutableSet<Object> elidedTypesAndStaticImports() {
+    return ImmutableSet.of(Collections.class);
+  }
+
+  List<Object> testImmutableListOfOne() {
+    Collections.singletonList(1);
+    Collections.singletonList("foo");
+    List.of(1);
+    return List.of("bar");
+  }
+}
--- a/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment2RulesTestOutput.java
+++ b/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment2RulesTestOutput.java
@@ -0,0 +1,21 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import java.util.Collections;
+import java.util.List;
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class WorkshopAssignment2RulesTest implements RefasterRuleCollectionTestCase {
+  @Override
+  public ImmutableSet<Object> elidedTypesAndStaticImports() {
+    return ImmutableSet.of(Collections.class);
+  }
+
+  List<Object> testImmutableListOfOne() {
+    ImmutableList.of(1);
+    ImmutableList.of("foo");
+    ImmutableList.of(1);
+    return ImmutableList.of("bar");
+  }
+}
--- a/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment3RulesTestInput.java
+++ b/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment3RulesTestInput.java
@@ -0,0 +1,24 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class WorkshopAssignment3RulesTest implements RefasterRuleCollectionTestCase {
+  void testCheckArgumentWithoutMessage() {
+    if (!"foo".isEmpty()) {
+      throw new IllegalArgumentException();
+    }
+    if (!"bar".isEmpty()) {
+      throw new IllegalArgumentException();
+    }
+  }
+
+  void testCheckArgumentWithMessage() {
+    if (!"foo".isEmpty()) {
+      throw new IllegalArgumentException("The string is not empty");
+    }
+    if (!"bar".isEmpty()) {
+      throw new IllegalArgumentException(
+          "The rule should be able rewrite all kinds of messages ;).");
+    }
+  }
+}
--- a/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment3RulesTestOutput.java
+++ b/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment3RulesTestOutput.java
@@ -0,0 +1,17 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class WorkshopAssignment3RulesTest implements RefasterRuleCollectionTestCase {
+  void testCheckArgumentWithoutMessage() {
+    checkArgument("foo".isEmpty());
+    checkArgument("bar".isEmpty());
+  }
+
+  void testCheckArgumentWithMessage() {
+    checkArgument("foo".isEmpty(), "The string is not empty");
+    checkArgument("bar".isEmpty(), "The rule should be able rewrite all kinds of messages ;).");
+  }
+}
--- a/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment4RulesTestInput.java
+++ b/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment4RulesTestInput.java
@@ -0,0 +1,25 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import com.google.common.collect.ImmutableSet;
+import java.math.RoundingMode;
+import java.util.Objects;
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class WorkshopAssignment4RulesTest implements RefasterRuleCollectionTestCase {
+  @Override
+  public ImmutableSet<Object> elidedTypesAndStaticImports() {
+    return ImmutableSet.of(Objects.class);
+  }
+
+  ImmutableSet<Boolean> testPrimitiveOrReferenceEqualityEnum() {
+    // Don't pay attention to the `ImmutableSet#of` here, it's just syntactical sugar for the
+    // testing framework.
+    return ImmutableSet.of(
+        "foo".equals("bar"),
+        Integer.valueOf(1).equals(2),
+        RoundingMode.UP.equals(RoundingMode.DOWN),
+        Objects.equals(RoundingMode.UP, RoundingMode.DOWN),
+        !RoundingMode.UP.equals(RoundingMode.DOWN),
+        !Objects.equals(RoundingMode.UP, RoundingMode.DOWN));
+  }
+}
--- a/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment4RulesTestOutput.java
+++ b/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment4RulesTestOutput.java
@@ -0,0 +1,25 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import com.google.common.collect.ImmutableSet;
+import java.math.RoundingMode;
+import java.util.Objects;
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class WorkshopAssignment4RulesTest implements RefasterRuleCollectionTestCase {
+  @Override
+  public ImmutableSet<Object> elidedTypesAndStaticImports() {
+    return ImmutableSet.of(Objects.class);
+  }
+
+  ImmutableSet<Boolean> testPrimitiveOrReferenceEqualityEnum() {
+    // Don't pay attention to the `ImmutableSet#of` here, it's just syntactical sugar for the
+    // testing framework.
+    return ImmutableSet.of(
+        "foo".equals("bar"),
+        Integer.valueOf(1).equals(2),
+        RoundingMode.UP == RoundingMode.DOWN,
+        RoundingMode.UP == RoundingMode.DOWN,
+        RoundingMode.UP != RoundingMode.DOWN,
+        RoundingMode.UP != RoundingMode.DOWN);
+  }
+}
--- a/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment5RulesTestInput.java
+++ b/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment5RulesTestInput.java
@@ -0,0 +1,11 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import java.util.stream.Stream;
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class WorkshopAssignment5RulesTest implements RefasterRuleCollectionTestCase {
+  boolean testStreamDoAllMatch() {
+    boolean example = Stream.of("foo").noneMatch(s -> !s.isBlank());
+    return Stream.of("bar").noneMatch(b -> !b.startsWith("b"));
+  }
+}
--- a/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment5RulesTestOutput.java
+++ b/workshop/src/test/resources/tech/picnic/errorprone/workshop/refasterrules/WorkshopAssignment5RulesTestOutput.java
@@ -0,0 +1,11 @@
+package tech.picnic.errorprone.workshop.refasterrules;
+
+import java.util.stream.Stream;
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class WorkshopAssignment5RulesTest implements RefasterRuleCollectionTestCase {
+  boolean testStreamDoAllMatch() {
+    boolean example = Stream.of("foo").allMatch(s -> s.isBlank());
+    return Stream.of("bar").allMatch(b -> b.startsWith("b"));
+  }
+}