Add on-demand integration test workflow

.github/workflows/integration-test.yml

@@ -0,0 +1,36 @@
+name: On-demand integration test
+on:
+  # run action every time a new comment is created
+  issue_comment:
+    types: [ created ]
+permissions:
+  contents: read
+jobs:
+  on_demand_integration_test:
+    name: On-demand integration test
+    # Only run the integration test if the created comment is on a pull request
+    # and contains the string `/integration-test`
+    if: | 
+      github.event.issue.pull_request &&
+      contains(github.event.comment.body, '/integration-test')
+    # XXX TODO: Device matrix? 
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@8ade135a41bc03ea155e62e844d188df1ea18608 # v4.1
+        with:
+          submodules: 'recursive'
+          persist-credentials: false
+      - name: Set up JDK
+        uses: actions/setup-java@0ab4596768b603586c0de567f2430c30f5b0d2b0 # v3.13.0
+        with:
+          # XXX TODO: java version matrix?
+          java-version: 17.0.8
+          distribution: temurin
+          cache: maven
+      - name: Display build environment details
+        run: mvn --version
+      - name: Install error-prone-support snapshot
+        run: mvn -T1C install -DskipTests -Dverification.skip
+      - name: Run integration test
+        run: bash integration-tests/run.sh

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "integration-tests/checkstyle"]
+	path = integration-tests/checkstyle
+	url = [email protected]:checkstyle/checkstyle.git

integration-tests/checkstyle-checkstyle-10.9.3-init.patch

@@ -0,0 +1,131 @@
+diff --git a/config/archunit-store/slices-should-be-free-of-cycles-suppressions b/config/archunit-store/slices-should-be-free-of-cycles-suppressions
+index ea99a44ee..05a77e1e6 100644
+--- a/config/archunit-store/slices-should-be-free-of-cycles-suppressions
++++ b/config/archunit-store/slices-should-be-free-of-cycles-suppressions
+@@ -1351,8 +1351,8 @@ Cycle detected: Slice checks.javadoc -> \
+     - Constructor <com.puppycrawl.tools.checkstyle.checks.javadoc.AtclauseOrderCheck.<init>()> calls method <com.puppycrawl.tools.checkstyle.utils.TokenUtil.asBitSet([I)> in (AtclauseOrderCheck.java:177)\
+     - Method <com.puppycrawl.tools.checkstyle.checks.javadoc.JavadocTagContinuationIndentationCheck.visitJavadocToken(com.puppycrawl.tools.checkstyle.api.DetailNode)> calls method <com.puppycrawl.tools.checkstyle.utils.JavadocUtil.getNextSibling(com.puppycrawl.tools.checkstyle.api.DetailNode)> in (JavadocTagContinuationIndentationCheck.java:177)\
+     - Method <com.puppycrawl.tools.checkstyle.checks.javadoc.RequireEmptyLineBeforeBlockTagGroupCheck.isAnotherTagBefore(com.puppycrawl.tools.checkstyle.api.DetailNode)> calls method <com.puppycrawl.tools.checkstyle.utils.JavadocUtil.getPreviousSibling(com.puppycrawl.tools.checkstyle.api.DetailNode)> in (RequireEmptyLineBeforeBlockTagGroupCheck.java:177)\
++    - Method <com.puppycrawl.tools.checkstyle.checks.javadoc.JavadocNodeImpl.toString()> calls method <com.puppycrawl.tools.checkstyle.utils.JavadocUtil.getTokenName(int)> in (JavadocNodeImpl.java:178)\
+     - Method <com.puppycrawl.tools.checkstyle.checks.javadoc.JavadocTagInfo$8.isValidOn(com.puppycrawl.tools.checkstyle.api.DetailAST)> calls method <com.puppycrawl.tools.checkstyle.utils.ScopeUtil.isLocalVariableDef(com.puppycrawl.tools.checkstyle.api.DetailAST)> in (JavadocTagInfo.java:178)\
+-    - Method <com.puppycrawl.tools.checkstyle.checks.javadoc.JavadocNodeImpl.toString()> calls method <com.puppycrawl.tools.checkstyle.utils.JavadocUtil.getTokenName(int)> in (JavadocNodeImpl.java:179)\
+     - Method <com.puppycrawl.tools.checkstyle.checks.javadoc.AbstractJavadocCheck.setJavadocTokens([Ljava.lang.String;)> calls method <com.puppycrawl.tools.checkstyle.utils.JavadocUtil.getTokenId(java.lang.String)> in (AbstractJavadocCheck.java:181)\
+     - Method <com.puppycrawl.tools.checkstyle.checks.javadoc.RequireEmptyLineBeforeBlockTagGroupCheck.isAnotherTagBefore(com.puppycrawl.tools.checkstyle.api.DetailNode)> calls method <com.puppycrawl.tools.checkstyle.utils.JavadocUtil.getPreviousSibling(com.puppycrawl.tools.checkstyle.api.DetailNode)> in (RequireEmptyLineBeforeBlockTagGroupCheck.java:183)\
+     - Method <com.puppycrawl.tools.checkstyle.checks.javadoc.NonEmptyAtclauseDescriptionCheck.hasOnlyEmptyText(com.puppycrawl.tools.checkstyle.api.DetailNode)> calls method <com.puppycrawl.tools.checkstyle.utils.CommonUtil.isBlank(java.lang.String)> in (NonEmptyAtclauseDescriptionCheck.java:185)\
+diff --git a/pom.xml b/pom.xml
+index 6169c87e0..491c7fa88 100644
+--- a/pom.xml
++++ b/pom.xml
+@@ -230,10 +230,12 @@
+     <pitest.junit5.plugin.version>1.1.2</pitest.junit5.plugin.version>
+     <pitest.accelerator.junit5.plugin.version>1.0.4</pitest.accelerator.junit5.plugin.version>
+     <sonar.test.exclusions>**/test/resources/**/*,**/it/resources/**/*</sonar.test.exclusions>
++    <assertj.version>3.24.2</assertj.version>
+     <junit.version>5.9.2</junit.version>
+     <forbiddenapis.version>3.4</forbiddenapis.version>
+     <json-schema-validator.version>1.2.0</json-schema-validator.version>
+-    <error-prone.version>2.18.0</error-prone.version>
++    <error-prone.version>2.22.0</error-prone.version>
++    <error-prone-support.version>0.14.0</error-prone-support.version>
+     <checkerframework.version>3.27.0</checkerframework.version>
+   </properties>
+
+@@ -277,6 +279,12 @@
+     </dependency>
+
+     <!-- test scope stuff -->
++    <dependency>
++      <groupId>org.assertj</groupId>
++      <artifactId>assertj-core</artifactId>
++      <version>${assertj.version}</version>
++      <scope>test</scope>
++    </dependency>
+     <dependency>
+       <groupId>org.junit.jupiter</groupId>
+       <artifactId>junit-jupiter-api</artifactId>
+@@ -2305,7 +2313,7 @@
+                     <arg>-Xpkginfo:always</arg>
+                     <arg>-XDcompilePolicy=simple</arg>
+                     <arg>
+-                      -Xplugin:ErrorProne
++                      -Xplugin:ErrorProne ${error-prone.flags}
+                     </arg>
+                   </compilerArgs>
+                   <annotationProcessorPaths>
+@@ -2314,6 +2322,16 @@
+                       <artifactId>error_prone_core</artifactId>
+                       <version>${error-prone.version}</version>
+                     </path>
++                    <path>
++                      <groupId>tech.picnic.error-prone-support</groupId>
++                      <artifactId>error-prone-contrib</artifactId>
++                      <version>${error-prone-support.version}</version>
++                    </path>
++                    <path>
++                      <groupId>tech.picnic.error-prone-support</groupId>
++                      <artifactId>refaster-runner</artifactId>
++                      <version>${error-prone-support.version}</version>
++                    </path>
+                   </annotationProcessorPaths>
+                 </configuration>
+               </execution>
+@@ -2358,7 +2376,8 @@
+                     <arg>-XDcompilePolicy=simple</arg>
+                     <arg>
+                       -Xplugin:ErrorProne \
+-                      -XepExcludedPaths:.*[\\/]resources[\\/].*
++                      -XepExcludedPaths:.*[\\/]resources[\\/].* \
++                      ${error-prone.flags}
+                     </arg>
+                   </compilerArgs>
+                   <annotationProcessorPaths>
+@@ -2367,6 +2386,16 @@
+                       <artifactId>error_prone_core</artifactId>
+                       <version>${error-prone.version}</version>
+                     </path>
++                    <path>
++                      <groupId>tech.picnic.error-prone-support</groupId>
++                      <artifactId>error-prone-contrib</artifactId>
++                      <version>${error-prone-support.version}</version>
++                    </path>
++                    <path>
++                      <groupId>tech.picnic.error-prone-support</groupId>
++                      <artifactId>refaster-runner</artifactId>
++                      <version>${error-prone-support.version}</version>
++                    </path>
+                   </annotationProcessorPaths>
+                 </configuration>
+               </execution>
+diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/DetailNodeTreeStringPrinter.java b/src/main/java/com/puppycrawl/tools/checkstyle/DetailNodeTreeStringPrinter.java
+index 61c59b613..9019964ad 100644
+--- a/src/main/java/com/puppycrawl/tools/checkstyle/DetailNodeTreeStringPrinter.java
++++ b/src/main/java/com/puppycrawl/tools/checkstyle/DetailNodeTreeStringPrinter.java
+@@ -63,6 +63,7 @@ public final class DetailNodeTreeStringPrinter {
+      * @return DetailNode tree
+      * @throws IllegalArgumentException if there is an error parsing the Javadoc.
+      */
++    @SuppressWarnings("CheckArgumentWithMessage")
+     public static DetailNode parseJavadocAsDetailNode(DetailAST blockComment) {
+         final JavadocDetailNodeParser parser = new JavadocDetailNodeParser();
+         final ParseStatus status = parser.parseJavadocAsDetailNode(blockComment);
+diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/checks/javadoc/JavadocNodeImpl.java b/src/main/java/com/puppycrawl/tools/checkstyle/checks/javadoc/JavadocNodeImpl.java
+index fd90c4259..0c1b4f141 100644
+--- a/src/main/java/com/puppycrawl/tools/checkstyle/checks/javadoc/JavadocNodeImpl.java
++++ b/src/main/java/com/puppycrawl/tools/checkstyle/checks/javadoc/JavadocNodeImpl.java
+@@ -20,7 +20,6 @@
+ package com.puppycrawl.tools.checkstyle.checks.javadoc;
+
+ import java.util.Arrays;
+-import java.util.Objects;
+ import java.util.Optional;
+
+ import com.puppycrawl.tools.checkstyle.api.DetailNode;
+@@ -180,7 +179,7 @@ public class JavadocNodeImpl implements DetailNode {
+                 + ", text='" + text + '\''
+                 + ", lineNumber=" + lineNumber
+                 + ", columnNumber=" + columnNumber
+-                + ", children=" + Objects.hashCode(children)
++                + ", children=" + Arrays.hashCode(children)
+                 + ", parent=" + parent + ']';
+     }
+

integration-tests/run.sh

@@ -0,0 +1,109 @@
+#!/usr/bin/env bash
+
+set -e -u -o pipefail
+
+project=checkstyle
+revision=checkstyle-10.9.3
+
+if [ "${#}" -gt 1 ] || [[ ${1:---sync} != '--sync' ]]; then
+  echo "Usage: ${0} [--sync]"
+  exit 1
+fi
+do_sync="${1:-}"
+
+error_prone_support_version="$(
+ mvn -f .. help:evaluate -Dexpression=project.version -q -DforceStdout
+)"
+
+error_prone_shared_flags='-XepExcludedPaths:(\Q${project.basedir}${file.separator}src${file.separator}\E(it|test)\Q${file.separator}resources\E|\Q${project.build.directory}${file.separator}\E).*'
+
+error_prone_patch_flags="${error_prone_shared_flags} -XepPatchLocation:IN_PLACE -XepPatchChecks:$(
+  find .. -path "*/META-INF/services/com.google.errorprone.bugpatterns.BugChecker" \
+    | xargs grep -hoP '[^.]+$' \
+    | paste -s -d ','
+)"
+
+error_prone_validation_flags="${error_prone_shared_flags} -XepDisableAllChecks $(
+  find .. -path "*/META-INF/services/com.google.errorprone.bugpatterns.BugChecker" \
+    | xargs grep -hoP '[^.]+$' \
+    | sed -r 's,(.*),-Xep:\1:WARN,' \
+    | paste -s -d ' '
+)"
+
+validation_log_file="$(mktemp)"
+trap 'rm -rf -- "${validation_log_file}"' INT TERM HUP EXIT
+
+echo "Error Prone Support version: ${error_prone_support_version}"
+echo "Error Prone patch flags: ${error_prone_patch_flags}"
+echo "Error Prone validation flags: ${error_prone_validation_flags}"
+
+pushd "${project}"
+
+git checkout -f "${revision}"
+git apply < "../${project}-${revision}-init.patch"
+git commit -m 'dependency: Introduce Error Prone Support' .
+
+mvn com.spotify.fmt:fmt-maven-plugin:2.19:format \
+  -DadditionalSourceDirectories='${project.basedir}${file.separator}src${file.separator}it${file.separator}java'
+git commit -m 'minor: Reformat using Google Java Format' .
+
+function apply_patch() {
+  local current_diff="${1}"
+
+  mvn clean package com.spotify.fmt:fmt-maven-plugin:2.19:format \
+    -DadditionalSourceDirectories='${project.basedir}${file.separator}src${file.separator}it${file.separator}java' \
+    -Perror-prone-compile,error-prone-test-compile \
+    -Derror-prone.flags="${error_prone_patch_flags}" \
+    -Derror-prone-support.version="${error_prone_support_version}" \
+    -DskipTests
+
+  local new_diff="$(git diff | shasum --algorithm 256)"
+
+  if [ "${current_diff}" != "${new_diff}" ]; then
+    apply_patch "${new_diff}"
+  fi
+}
+
+apply_patch "$(git diff | shasum --algorithm 256)"
+
+baseline_patch="../${project}-${revision}-expected-changes.patch"
+if [ -n "${do_sync}" ]; then
+  echo 'Saving changes...'
+  git diff > "${baseline_patch}"
+else
+  echo 'Inspecting changes...'
+  if ! diff -u "${baseline_patch}" <(git diff); then
+    echo 'There are unexpected changes.'
+    exit 1
+  fi
+fi
+
+# Validate the results.
+#
+# - The `metadataFilesGenerationAllFiles` test is skipped because is makes line
+#   number assertions that will fail when the code is formatted or patched.
+# - The `allCheckSectionJavaDocs` test is skipped because is validates that
+#   Javadoc has certain closing tags that are removed by Google Java Format.
+# XXX: Figure out why the `validateCliDocSections` test fails.
+echo "Validation file: ${validation_log_file}"
+mvn clean package \
+    -Perror-prone-compile,error-prone-test-compile \
+    -Derror-prone.flags="${error_prone_validation_flags}" \
+    -Derror-prone-support.version="${error_prone_support_version}" \
+    -Dmaven.compiler.showWarnings \
+  | tee "${validation_log_file}"
+echo "Finished validation run!"
+
+baseline_warnings="../${project}-${revision}-expected-warnings.txt"
+# note: added '*' in the final grep, required in order to get matches in GNU grep 3.11
+generated_warnings="$(grep -oP "(?<=^\\Q[WARNING] ${PWD}/\\E).*" "${validation_log_file}" | grep -P '\]*\[')"
+if [ -n "${do_sync}" ]; then
+  echo 'Saving emitted warnings...'
+  echo "${generated_warnings}" > "${baseline_warnings}"
+else
+  echo 'Inspecting emitted warnings...'
+  if ! diff -u "${baseline_warnings}" <(echo "${generated_warnings}"); then
+    echo 'Diagnostics output changed.'
+    exit 1
+  fi
+fi