Target Java 21, build with Java 25

.github/ISSUE_TEMPLATE/bug_report.md

@@ -41,10 +41,10 @@ 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. `17.0.16`).
-- Error Prone version (e.g. `2.41.0`).
-- Error Prone Support version (e.g. `0.24.0`).
+- Operating system (e.g. MacOS Tahoe).
+- Java version (i.e. `java --version`, e.g. `21.0.8`).
+- Error Prone version (e.g. `2.43.0`).
+- Error Prone Support version (e.g. `0.26.0`).
 
 ### Additional context
 

.github/workflows/build.yml

@@ -19,12 +19,8 @@ jobs:
     strategy:
       matrix:
         os: [ ubuntu-24.04, macos-15, windows-2025 ]
-        build-jdk: [ 21.0.8 ]
-        target-jdk: [ 17.0.16 ]
-        include:
-          - os: ubuntu-24.04
-            build-jdk: 25
-            target-jdk: 17.0.16
+        build-jdk: [ 25 ]
+        target-jdk: [ 21.0.8 ]
     runs-on: ${{ matrix.os }}
     steps:
       - name: Install Harden-Runner
@@ -84,7 +80,7 @@ jobs:
       - name: Check out code and set up JDK and Maven
         uses: s4u/setup-maven-action@6c4e9964d4ecb8f1026310cd8618791fd51a8016 # v1.19.0
         with:
-          java-version: 21.0.8
+          java-version: 25
           java-distribution: temurin
           maven-version: 3.9.11
       - name: Build and deploy

.github/workflows/codeql.yml

@@ -40,7 +40,7 @@ jobs:
       - name: Check out code and set up JDK and Maven
         uses: s4u/setup-maven-action@6c4e9964d4ecb8f1026310cd8618791fd51a8016 # v1.19.0
         with:
-          java-version: 21.0.8
+          java-version: 25
           java-distribution: temurin
           maven-version: 3.9.11
       - name: Initialize CodeQL

.github/workflows/error-prone-compat.yml

@@ -38,7 +38,7 @@ jobs:
       - name: Check out code and set up JDK and Maven
         uses: s4u/setup-maven-action@6c4e9964d4ecb8f1026310cd8618791fd51a8016 # v1.19.0
         with:
-          java-version: 21.0.8
+          java-version: 25
           java-distribution: temurin
           maven-version: 3.9.11
       - name: Quickly build and install project

.github/workflows/integration-tests.yml

@@ -63,7 +63,7 @@ jobs:
         uses: s4u/setup-maven-action@6c4e9964d4ecb8f1026310cd8618791fd51a8016 # v1.19.0
         with:
           checkout-ref: ${{ github.event.issue.pull_request && format('refs/pull/{0}/head', github.event.issue.number) || github.ref }}
-          java-version: 21.0.8
+          java-version: 25
           java-distribution: temurin
           maven-version: 3.9.11
       - name: Install project to local Maven repository

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

@@ -29,7 +29,7 @@ jobs:
         uses: s4u/setup-maven-action@6c4e9964d4ecb8f1026310cd8618791fd51a8016 # v1.19.0
         with:
           checkout-fetch-depth: 2
-          java-version: 21.0.8
+          java-version: 25
           java-distribution: temurin
           maven-version: 3.9.11
       - name: Run Pitest

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

@@ -36,7 +36,7 @@ jobs:
       - name: Check out code and set up JDK and Maven
         uses: s4u/setup-maven-action@6c4e9964d4ecb8f1026310cd8618791fd51a8016 # v1.19.0
         with:
-          java-version: 21.0.8
+          java-version: 25
           java-distribution: temurin
           maven-version: 3.9.11
       - name: Download Pitest analysis artifact

.github/workflows/reviewdog.yml

@@ -31,7 +31,7 @@ jobs:
       - name: Check out code and set up JDK and Maven
         uses: s4u/setup-maven-action@6c4e9964d4ecb8f1026310cd8618791fd51a8016 # v1.19.0
         with:
-          java-version: 21.0.8
+          java-version: 25
           java-distribution: temurin
           maven-version: 3.9.11
       - name: Set up Reviewdog

.github/workflows/sonarcloud.yml

@@ -39,7 +39,7 @@ jobs:
         uses: s4u/setup-maven-action@6c4e9964d4ecb8f1026310cd8618791fd51a8016 # v1.19.0
         with:
           checkout-fetch-depth: 0
-          java-version: 21.0.8
+          java-version: 25
           java-distribution: temurin
           maven-version: 3.9.11
       - name: Create missing `test` directory

.mvn/jvm.config

@@ -1,5 +1,3 @@
--XX:ReservedCodeCacheSize=512m
--XX:SoftRefLRUPolicyMSPerMB=10
 -XX:+UseParallelGC
 --add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED
 --add-exports=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED

.sdkmanrc

@@ -0,0 +1,3 @@
+java=25-tem
+maven=3.9.11
+mvnd=1.0.3

README.md

@@ -50,7 +50,7 @@ high-quality and consistent Java code_][picnic-blog-ep-post].
 
 This library is built on top of [Error Prone][error-prone-orig-repo]. To use
 it, read the installation guide for Maven or Gradle below. The library requires
-that your build is executed using JDK 17 or above, but supports builds that
+that your build is executed using JDK 21 or above, but supports builds that
 [target][baeldung-java-source-target-options] older versions of Java.
 
 #### Maven
@@ -188,7 +188,8 @@ rules][refaster-rules].
 
 This is a [Maven][maven] project, so running `mvn clean install` performs a
 full clean build and installs the library to your local Maven repository. While
-the project targets JDK 17, building it requires JDK 21.
+the project targets JDK 21, building it requires JDK 25. If you use
+[SDKMAN!][sdmkan], simply run `sdk env` to configure the current shell.
 
 Once you've made changes, the build may fail due to a warning or error emitted
 by static code analysis. The flags and commands listed below allow you to
@@ -322,6 +323,7 @@ OSS license generously provided by [Arcmutate][arcmutate]. Check them out!
 [script-run-branch-mutation-tests]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/run-branch-mutation-tests.sh
 [script-run-full-build]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/run-full-build.sh
 [script-run-mutation-tests]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/run-mutation-tests.sh
+[sdkman]: https://sdkman.io
 [security]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/SECURITY.md
 [sonarcloud-coverage-badge]: https://sonarcloud.io/api/project_badges/measure?project=PicnicSupermarket_error-prone-support&metric=coverage
 [sonarcloud-coverage-master]: https://sonarcloud.io/component_measures?id=PicnicSupermarket_error-prone-support&metric=coverage

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

@@ -128,9 +128,9 @@ private ImmutableList<BugPatternTestCase> getCollectedTests() {
     private static Optional<String> getClassUnderTest(
         MethodInvocationTree tree, VisitorState state) {
       if (TEST_HELPER_NEW_INSTANCE.matches(tree, state)) {
-        return Optional.ofNullable(ASTHelpers.getSymbol(tree.getArguments().get(0)))
+        return Optional.ofNullable(ASTHelpers.getSymbol(tree.getArguments().getFirst()))
             .filter(s -> !s.type.allparams().isEmpty())
-            .map(s -> s.type.allparams().get(0).tsym.getQualifiedName().toString());
+            .map(s -> s.type.allparams().getFirst().tsym.getQualifiedName().toString());
       }
 
       ExpressionTree receiver = ASTHelpers.getReceiver(tree);
@@ -142,7 +142,7 @@ private static Optional<String> getClassUnderTest(
     private static void extractIdentificationBugPatternTestCases(
         MethodInvocationTree tree, List<TestEntry> sink, VisitorState state) {
       if (IDENTIFICATION_SOURCE_LINES.matches(tree, state)) {
-        String path = ASTHelpers.constValue(tree.getArguments().get(0), String.class);
+        String path = ASTHelpers.constValue(tree.getArguments().getFirst(), String.class);
         Optional<String> sourceCode =
             getSourceCode(tree).filter(s -> s.contains("// BUG: Diagnostic"));
         if (path != null && sourceCode.isPresent()) {
@@ -169,7 +169,7 @@ private static void extractReplacementBugPatternTestCases(
                 requireNonNull(
                     ASTHelpers.getReceiver(tree), "Instance method invocation must have receiver");
 
-        String path = ASTHelpers.constValue(inputTree.getArguments().get(0), String.class);
+        String path = ASTHelpers.constValue(inputTree.getArguments().getFirst(), String.class);
         Optional<String> inputCode = getSourceCode(inputTree);
         if (path != null && inputCode.isPresent()) {
           Optional<String> outputCode =

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

@@ -31,9 +31,8 @@ public static void compileWithDocumentationGenerator(
       String outputDirectory, String path, String... lines) {
     /*
      * The compiler options specified here largely match those used by Error Prone's
-     * `CompilationTestHelper`. A key difference is the stricter linting configuration. When
-     * compiling using JDK 21+, these lint options also require that certain JDK modules are
-     * explicitly exported.
+     * `CompilationTestHelper`. A key difference is the stricter linting configuration, which in
+     * turn also requires that certain JDK modules are explicitly exported.
      */
     compile(
         ImmutableList.of(

error-prone-contrib/pom.xml

@@ -218,11 +218,6 @@
             <artifactId>rewrite-java</artifactId>
             <scope>provided</scope>
         </dependency>
-        <dependency>
-            <groupId>org.openrewrite</groupId>
-            <artifactId>rewrite-java-17</artifactId>
-            <scope>test</scope>
-        </dependency>
         <dependency>
             <groupId>org.openrewrite</groupId>
             <artifactId>rewrite-java-21</artifactId>

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

@@ -87,7 +87,7 @@ private static Optional<Fix> dropRedundantValueAttribute(
       return Optional.empty();
     }
 
-    ExpressionTree arg = args.get(0);
+    ExpressionTree arg = args.getFirst();
     if (state.getSourceForNode(arg) == null) {
       /*
        * The annotation argument doesn't have a source representation, e.g. because `value` isn't
@@ -139,7 +139,7 @@ private static Optional<String> simplifyAttributeValue(ExpressionTree expr, Visi
   private static Optional<String> simplifySingletonArray(NewArrayTree array, VisitorState state) {
     return Optional.of(array.getInitializers())
         .filter(initializers -> initializers.size() == 1)
-        .map(initializers -> SourceCode.treeToString(initializers.get(0), state));
+        .map(initializers -> SourceCode.treeToString(initializers.getFirst(), state));
   }
 
   private static Optional<String> dropTrailingComma(NewArrayTree array, VisitorState state) {

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

@@ -75,7 +75,7 @@ public Description matchBlock(BlockTree tree, VisitorState state) {
       return Description.NO_MATCH;
     }
 
-    StatementTree finalStatement = statements.get(statements.size() - 1);
+    StatementTree finalStatement = statements.getLast();
     if (!VARIABLE_RETURN.matches(finalStatement, state)) {
       return Description.NO_MATCH;
     }
@@ -105,24 +105,20 @@ public Description matchBlock(BlockTree tree, VisitorState state) {
   }
 
   private static Optional<ExpressionTree> tryMatchAssignment(Symbol targetSymbol, Tree tree) {
-    if (tree instanceof ExpressionStatementTree expressionStatement) {
-      return tryMatchAssignment(targetSymbol, expressionStatement.getExpression());
-    }
-
-    if (tree instanceof AssignmentTree assignment) {
-      return targetSymbol.equals(ASTHelpers.getSymbol(assignment.getVariable()))
-          ? Optional.of(assignment.getExpression())
-          : Optional.empty();
-    }
-
-    if (tree instanceof VariableTree declaration) {
-      return declaration.getModifiers().getAnnotations().isEmpty()
-              && targetSymbol.equals(ASTHelpers.getSymbol(declaration))
-          ? Optional.ofNullable(declaration.getInitializer())
-          : Optional.empty();
-    }
-
-    return Optional.empty();
+    return switch (tree) {
+      case ExpressionStatementTree expressionStatement ->
+          tryMatchAssignment(targetSymbol, expressionStatement.getExpression());
+      case AssignmentTree assignment ->
+          targetSymbol.equals(ASTHelpers.getSymbol(assignment.getVariable()))
+              ? Optional.of(assignment.getExpression())
+              : Optional.empty();
+      case VariableTree declaration ->
+          declaration.getModifiers().getAnnotations().isEmpty()
+                  && targetSymbol.equals(ASTHelpers.getSymbol(declaration))
+              ? Optional.ofNullable(declaration.getInitializer())
+              : Optional.empty();
+      default -> Optional.empty();
+    };
   }
 
   /**

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

@@ -134,7 +134,7 @@ private Description analyzeFormatStringContext(
   private Description analyzeRequireNonNullStringFormatContext(
       StringFormatExpression stringFormat, MethodInvocationTree context) {
     List<? extends ExpressionTree> arguments = context.getArguments();
-    if (arguments.size() != 2 || arguments.get(0).equals(stringFormat.expression())) {
+    if (arguments.size() != 2 || arguments.getFirst().equals(stringFormat.expression())) {
       /* Vacuous validation that string formatting doesn't yield `null`. */
       return buildDescription(context).setMessage(MESSAGE_NEVER_NULL_ARGUMENT).build();
     }
@@ -157,7 +157,7 @@ private Description analyzeRequireNonNullStringFormatContext(
   private Description analyzeGuavaGuardStringFormatContext(
       StringFormatExpression stringFormat, MethodInvocationTree context, VisitorState state) {
     List<? extends ExpressionTree> arguments = context.getArguments();
-    if (arguments.get(0).equals(stringFormat.expression())) {
+    if (arguments.getFirst().equals(stringFormat.expression())) {
       /*
        * Vacuous `checkNotNull` or `verifyNotNull` validation that string formatting doesn't yield
        * `null`.
@@ -185,8 +185,8 @@ private Description analyzeSlf4jLoggerStringFormatContext(
     }
 
     List<? extends ExpressionTree> arguments = context.getArguments();
-    int leftOffset = SLF4J_MARKER.matches(arguments.get(0), state) ? 1 : 0;
-    int rightOffset = THROWABLE.matches(arguments.get(arguments.size() - 1), state) ? 1 : 0;
+    int leftOffset = SLF4J_MARKER.matches(arguments.getFirst(), state) ? 1 : 0;
+    int rightOffset = THROWABLE.matches(arguments.getLast(), state) ? 1 : 0;
     if (arguments.size() != leftOffset + 1 + rightOffset) {
       /*
        * The format string produces a format string itself, or its result is the input to another
@@ -258,7 +258,7 @@ private static Optional<StringFormatExpression> tryCreate(
 
       if (STATIC_FORMAT_STRING.matches(tree, state)) {
         List<? extends ExpressionTree> arguments = tree.getArguments();
-        int argOffset = LOCALE.matches(arguments.get(0), state) ? 1 : 0;
+        int argOffset = LOCALE.matches(arguments.getFirst(), state) ? 1 : 0;
         return Optional.of(
             create(
                 tree,

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

@@ -93,7 +93,7 @@
                   .named("copyOf"),
               symbolMatcher(
                   (symbol, state) ->
-                      state.getTypes().isArray(((MethodSymbol) symbol).params().get(0).type))),
+                      state.getTypes().isArray(((MethodSymbol) symbol).params().getFirst().type))),
           staticMethod().onClass(Arrays.class.getCanonicalName()).named("asList"));
   private static final Matcher<ExpressionTree> FLUX =
       staticMethod().onDescendantOf("reactor.core.publisher.Flux");
@@ -141,7 +141,7 @@
       return Description.NO_MATCH;
     }
 
-    ExpressionTree argument = tree.getArguments().get(0);
+    ExpressionTree argument = tree.getArguments().getFirst();
     if (!EXPLICIT_ITERABLE_CREATOR.matches(argument, state)) {
       return Description.NO_MATCH;
     }
@@ -156,7 +156,7 @@
     List<VarSymbol> params = method.params();
     return !method.isVarArgs()
         && params.size() == 1
-        && ASTHelpers.isSubtype(params.get(0).type, state.getSymtab().iterableType, state);
+        && ASTHelpers.isSubtype(params.getFirst().type, state.getSymtab().iterableType, state);
   }
 
   private static boolean isLocalOverload(MethodSymbol calledMethod, VisitorState state) {

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

@@ -105,7 +105,7 @@ public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState
       return Description.NO_MATCH;
     }
 
-    ExpressionTree sourceTree = arguments.get(0);
+    ExpressionTree sourceTree = arguments.getFirst();
     Type sourceType = ASTHelpers.getType(sourceTree);
     Type resultType = ASTHelpers.getType(tree);
     TargetType targetType = TargetType.targetType(state);

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

@@ -90,7 +90,7 @@ public Description matchModifiers(ModifiersTree tree, VisitorState state) {
     }
 
     return describeMatch(
-        originalOrdering.get(0), fixOrdering(originalOrdering, sortedAnnotations, state));
+        originalOrdering.getFirst(), fixOrdering(originalOrdering, sortedAnnotations, state));
   }
 
   private static ImmutableList<? extends AnnotationTree> sort(

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

@@ -20,8 +20,10 @@
 import com.google.errorprone.matchers.Description;
 import com.google.errorprone.matchers.Matcher;
 import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.AssignmentTree;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MethodInvocationTree;
+import com.sun.source.tree.ReturnTree;
 import com.sun.source.tree.Tree;
 import com.sun.source.tree.VariableTree;
 import java.util.List;
@@ -64,18 +66,18 @@ public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState
     }
 
     List<? extends ExpressionTree> arguments = tree.getArguments();
-    return describeMatch(tree, SuggestedFixes.removeElement(arguments.get(0), arguments, state));
+    return describeMatch(
+        tree, SuggestedFixes.removeElement(arguments.getFirst(), arguments, state));
   }
 
-  // XXX: Use switch pattern matching once the targeted JDK supports this.
   private static boolean isTypeDerivableFromContext(MethodInvocationTree tree, VisitorState state) {
     Tree parent = state.getPath().getParentPath().getLeaf();
-    return switch (parent.getKind()) {
-      case VARIABLE ->
-          !ASTHelpers.hasImplicitType((VariableTree) parent, state)
-              && MoreASTHelpers.areSameType(tree, parent, state);
-      case ASSIGNMENT -> MoreASTHelpers.areSameType(tree, parent, state);
-      case RETURN ->
+    return switch (parent) {
+      case VariableTree variable ->
+          !ASTHelpers.hasImplicitType(variable, state)
+              && MoreASTHelpers.areSameType(tree, variable, state);
+      case AssignmentTree assignment -> MoreASTHelpers.areSameType(tree, assignment, state);
+      case ReturnTree returnTree ->
           MoreASTHelpers.findMethodExitedOnReturn(state)
               .filter(m -> MoreASTHelpers.areSameType(tree, m.getReturnType(), state))
               .isPresent();