WIP: Introduce Refaster IsNullable matcher

As-is the tests fail, since the analysis assumes (in general) that
parameters and method return types are nullable by default. For our
purposes we want a more "optimistic" implementation. See about modifying
the configuration, or (perhaps) delegating to NullAway instead.

.github/workflows/build.yml

@@ -14,7 +14,7 @@ jobs:
         distribution: [ temurin ]
         experimental: [ false ]
         include:
-          - os: macos-12
+          - os: macos-14
             jdk: 17.0.8
             distribution: temurin
             experimental: false

.github/workflows/codeql.yml

@@ -28,13 +28,13 @@ jobs:
           java-distribution: temurin
           maven-version: 3.9.6
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@012739e5082ff0c22ca6d6ab32e07c36df03c4a4 # v3.22.12
+        uses: github/codeql-action/init@b7bf0a3ed3ecfa44160715d7c442788f65f0f923 # v3.23.2
         with:
           languages: ${{ matrix.language }}
       - name: Perform minimal build
         if: matrix.language == 'java'
         run: mvn -T1C clean package -DskipTests -Dverification.skip
       - name: Perform CodeQL analysis
-        uses: github/codeql-action/analyze@012739e5082ff0c22ca6d6ab32e07c36df03c4a4 # v3.22.12
+        uses: github/codeql-action/analyze@b7bf0a3ed3ecfa44160715d7c442788f65f0f923 # v3.23.2
         with:
           category: /language:${{ matrix.language }}

.github/workflows/deploy-website.yml

@@ -15,7 +15,7 @@ jobs:
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
         with:
           persist-credentials: false
-      - uses: ruby/setup-ruby@360dc864d5da99d54fcb8e9148c14a84b90d3e88 # v1.165.1
+      - uses: ruby/setup-ruby@bd03e04863f52d169e18a2b190e8fa6b84938215 # v1.170.0
         with:
           working-directory: ./website
           bundler-cache: true
@@ -32,7 +32,7 @@ jobs:
         # "Refaster rules" terminology on our website and in the code.
         run: bundle exec htmlproofer --disable_external true --check-external-hash false ./_site
       - name: Upload website as artifact
-        uses: actions/upload-pages-artifact@0252fc4ba7626f0298f0cf00902a25c6afc77fa8 # v3.0.0
+        uses: actions/upload-pages-artifact@56afc609e74202658d3ffba0e8f6dda462b719fa # v3.0.1
         with:
           path: ./website/_site
   deploy:
@@ -48,4 +48,4 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@87c3283f01cd6fe19a0ab93a23b2f6fcba5a8e42 # v4.0.3
+        uses: actions/deploy-pages@decdde0ac072f6dcbe43649d82d9c635fff5b4e4 # v4.0.4

.github/workflows/openssf-scorecard.yml

@@ -31,6 +31,6 @@ jobs:
           results_format: sarif
           publish_results: ${{ github.ref == 'refs/heads/master' }}
       - name: Update GitHub's code scanning dashboard
-        uses: github/codeql-action/upload-sarif@012739e5082ff0c22ca6d6ab32e07c36df03c4a4 # v3.22.12
+        uses: github/codeql-action/upload-sarif@b7bf0a3ed3ecfa44160715d7c442788f65f0f923 # v3.23.2
         with:
           sarif_file: results.sarif

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

@@ -28,7 +28,7 @@ jobs:
       - name: Aggregate Pitest reports
         run: mvn pitest-git:aggregate -DkilledEmoji=":tada:" -DmutantEmoji=":zombie:" -DtrailingText="Mutation testing report by [Pitest](https://pitest.org/). Review any surviving mutants by inspecting the line comments under [_Files changed_](${{ github.event.number }}/files)."
       - name: Upload Pitest reports as artifact
-        uses: actions/upload-artifact@694cdabd8bdb0f10b2cea11669e1bf5453eed0a6 # v4.2.0
+        uses: actions/upload-artifact@5d5d22a31266ced268874388b861e4b58bb5c2f3 # v4.3.1
         with:
           name: pitest-reports
           path: ./target/pit-reports-ci

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

@@ -28,12 +28,12 @@ jobs:
       - name: Install project to local Maven repository
         run: mvn -T1C install -DskipTests -Dverification.skip
       - name: Run integration test
-        run: xvfb-run ./integration-tests/checkstyle-10.12.4.sh "${{ runner.temp }}/artifacts"
+        run: xvfb-run ./integration-tests/checkstyle.sh "${{ runner.temp }}/artifacts"
       - name: Upload artifacts on failure
         if: ${{ failure() }}
-        uses: actions/upload-artifact@694cdabd8bdb0f10b2cea11669e1bf5453eed0a6 # v4.2.0
+        uses: actions/upload-artifact@5d5d22a31266ced268874388b861e4b58bb5c2f3 # v4.3.1
         with:
-          name: integration-test-checkstyle-10.12.4
+          name: integration-test-checkstyle
           path: "${{ runner.temp }}/artifacts"
       - name: Remove installed project artifacts
         run: mvn build-helper:remove-project-artifact

error-prone-contrib/pom.xml

@@ -48,6 +48,10 @@
             `annotationProcessorPaths` configuration below. -->
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>error-prone-utils</artifactId>
+        </dependency>
         <dependency>
             <groupId>${project.groupId}</groupId>
             <artifactId>refaster-support</artifactId>
@@ -73,10 +77,6 @@
             <artifactId>auto-value-annotations</artifactId>
             <scope>provided</scope>
         </dependency>
-        <dependency>
-            <groupId>com.google.googlejavaformat</groupId>
-            <artifactId>google-java-format</artifactId>
-        </dependency>
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
@@ -239,6 +239,11 @@
             <artifactId>spring-boot-test</artifactId>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.security</groupId>
+            <artifactId>spring-security-core</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.testng</groupId>
             <artifactId>testng</artifactId>

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

@@ -4,7 +4,7 @@ import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
 import static com.google.errorprone.BugPattern.StandardTags.LIKELY_ERROR;
 import static com.google.errorprone.matchers.Matchers.isType;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;

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

@@ -8,7 +8,7 @@ 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 static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;

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

@@ -6,7 +6,7 @@ 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 static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.Iterables;
@@ -23,7 +23,7 @@ import com.sun.source.tree.ClassTree;
 import com.sun.source.tree.MethodTree;
 import com.sun.source.tree.Tree;
 import java.util.List;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /** A {@link BugChecker} that flags redundant {@code @Autowired} constructor annotations. */
 @AutoService(BugChecker.class)

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

@@ -3,7 +3,7 @@ package tech.picnic.errorprone.bugpatterns;
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.ImmutableSet;
@@ -26,7 +26,7 @@ import java.util.Optional;
 import java.util.function.BiFunction;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /** A {@link BugChecker} that flags annotations that could be written more concisely. */
 @AutoService(BugChecker.class)

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

@@ -9,7 +9,7 @@ import static com.google.errorprone.matchers.Matchers.classLiteral;
 import static com.google.errorprone.matchers.Matchers.instanceMethod;
 import static com.google.errorprone.matchers.Matchers.receiverOfInvocation;
 import static com.google.errorprone.matchers.Matchers.toType;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;

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

@@ -4,7 +4,7 @@ import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
 import static com.google.errorprone.BugPattern.StandardTags.FRAGILE_CODE;
 import static com.google.errorprone.matchers.method.MethodMatchers.staticMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.ImmutableList;
@@ -25,7 +25,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.stream.Collector;
 import java.util.stream.Collectors;
-import tech.picnic.errorprone.bugpatterns.util.ThirdPartyLibrary;
+import tech.picnic.errorprone.utils.ThirdPartyLibrary;
 
 /**
  * A {@link BugChecker} that flags {@link Collector Collectors} that don't clearly express

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

@@ -11,7 +11,7 @@ import static com.google.errorprone.matchers.Matchers.not;
 import static com.google.errorprone.matchers.Matchers.returnStatement;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
 import static com.google.errorprone.matchers.Matchers.toType;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.Streams;
@@ -39,8 +39,8 @@ import com.sun.tools.javac.code.Symbol;
 import java.util.List;
 import java.util.Optional;
 import org.jspecify.annotations.Nullable;
-import tech.picnic.errorprone.bugpatterns.util.MoreASTHelpers;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.MoreASTHelpers;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags unnecessary local variable assignments preceding a return

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

@@ -7,7 +7,7 @@ import static com.google.errorprone.matchers.ChildMultiMatcher.MatchType.AT_LEAS
 import static com.google.errorprone.matchers.Matchers.annotations;
 import static com.google.errorprone.matchers.Matchers.anyOf;
 import static com.google.errorprone.matchers.Matchers.isType;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;
@@ -21,7 +21,7 @@ import com.sun.source.tree.ClassTree;
 import com.sun.source.tree.MethodTree;
 import com.sun.source.tree.Tree;
 import java.util.Optional;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /** A {@link BugChecker} that flags empty methods that seemingly can simply be deleted. */
 @AutoService(BugChecker.class)

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

@@ -7,7 +7,7 @@ import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
 import static com.google.errorprone.BugPattern.StandardTags.FRAGILE_CODE;
 import static com.google.errorprone.matchers.method.MethodMatchers.staticMethod;
 import static java.util.stream.Collectors.collectingAndThen;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.ImmutableSet;
@@ -72,7 +72,7 @@ public final class ExplicitEnumOrdering extends BugChecker implements MethodInvo
       List<? extends ExpressionTree> expressions) {
     return expressions.stream()
         .map(ASTHelpers::getSymbol)
-        .filter(Symbol::isEnum)
+        .filter(s -> s != null && s.isEnum())
         .collect(
             collectingAndThen(
                 toImmutableSetMultimap(Symbol::asType, Symbol::toString),

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

@@ -4,11 +4,11 @@ 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.method.MethodMatchers.instanceMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.generic;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.subOf;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.type;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.unbound;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.MoreTypes.generic;
+import static tech.picnic.errorprone.utils.MoreTypes.subOf;
+import static tech.picnic.errorprone.utils.MoreTypes.type;
+import static tech.picnic.errorprone.utils.MoreTypes.unbound;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.Iterables;

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

@@ -6,7 +6,7 @@ import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
 import static com.google.errorprone.BugPattern.StandardTags.CONCURRENCY;
 import static com.google.errorprone.BugPattern.StandardTags.PERFORMANCE;
 import static com.google.errorprone.matchers.method.MethodMatchers.instanceMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.ImmutableList;
@@ -27,7 +27,7 @@ import com.sun.tools.javac.code.Type;
 import com.sun.tools.javac.util.Position;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
-import tech.picnic.errorprone.bugpatterns.util.ThirdPartyLibrary;
+import tech.picnic.errorprone.utils.ThirdPartyLibrary;
 
 /**
  * A {@link BugChecker} that flags {@link reactor.core.publisher.Flux} operator usages that may

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

@@ -10,7 +10,7 @@ import static com.google.errorprone.matchers.Matchers.instanceMethod;
 import static com.google.errorprone.matchers.Matchers.not;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
 import static java.util.stream.Collectors.joining;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.base.Preconditions;
@@ -36,7 +36,7 @@ import java.util.Formatter;
 import java.util.List;
 import java.util.Optional;
 import org.jspecify.annotations.Nullable;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags string concatenations that produce a format string; in such cases

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

@@ -7,7 +7,7 @@ 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 static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.ImmutableBiMap;
@@ -41,7 +41,7 @@ import com.sun.tools.javac.code.Type;
 import com.sun.tools.javac.code.Types;
 import java.util.Arrays;
 import java.util.List;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /** A {@link BugChecker} that flags redundant identity conversions. */
 // XXX: Consider detecting cases where a flagged expression is passed to a method, and where removal

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

@@ -11,7 +11,7 @@ import static com.google.errorprone.matchers.Matchers.hasModifier;
 import static com.google.errorprone.matchers.Matchers.isSubtypeOf;
 import static com.google.errorprone.matchers.Matchers.methodReturns;
 import static com.google.errorprone.matchers.Matchers.not;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;

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

@@ -3,7 +3,7 @@ package tech.picnic.errorprone.bugpatterns;
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.Iterables;
@@ -18,15 +18,14 @@ import com.sun.source.tree.InstanceOfTree;
 import com.sun.source.tree.LambdaExpressionTree;
 import com.sun.source.tree.Tree.Kind;
 import com.sun.source.tree.VariableTree;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags lambda expressions that can be replaced with a method reference
  * of the form {@code T.class::isInstance}.
- *
- * @see MethodReferenceUsage
  */
-// XXX: Consider folding this logic into the `MethodReferenceUsage` check.
+// XXX: Consider folding this logic into the `MethodReferenceUsage` check of the
+// `error-prone-experimental` module.
 @AutoService(BugChecker.class)
 @BugPattern(
     summary = "Prefer `Class::isInstance` method reference over equivalent lambda expression",

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

@@ -11,9 +11,9 @@ import static com.google.errorprone.matchers.Matchers.hasMethod;
 import static com.google.errorprone.matchers.Matchers.hasModifier;
 import static com.google.errorprone.matchers.Matchers.isType;
 import static com.google.errorprone.matchers.Matchers.not;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
-import static tech.picnic.errorprone.bugpatterns.util.MoreJUnitMatchers.TEST_METHOD;
-import static tech.picnic.errorprone.bugpatterns.util.MoreMatchers.hasMetaAnnotation;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.MoreJUnitMatchers.TEST_METHOD;
+import static tech.picnic.errorprone.utils.MoreMatchers.hasMetaAnnotation;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.ImmutableSet;

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

@@ -8,9 +8,9 @@ import static com.google.errorprone.matchers.Matchers.enclosingClass;
 import static com.google.errorprone.matchers.Matchers.hasModifier;
 import static com.google.errorprone.matchers.Matchers.not;
 import static java.util.function.Predicate.not;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
-import static tech.picnic.errorprone.bugpatterns.util.MoreJUnitMatchers.SETUP_OR_TEARDOWN_METHOD;
-import static tech.picnic.errorprone.bugpatterns.util.MoreJUnitMatchers.TEST_METHOD;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.MoreJUnitMatchers.SETUP_OR_TEARDOWN_METHOD;
+import static tech.picnic.errorprone.utils.MoreJUnitMatchers.TEST_METHOD;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.ImmutableSet;
@@ -28,7 +28,7 @@ import com.sun.source.tree.MethodTree;
 import com.sun.tools.javac.code.Symbol.MethodSymbol;
 import java.util.Optional;
 import javax.lang.model.element.Modifier;
-import tech.picnic.errorprone.bugpatterns.util.ConflictDetection;
+import tech.picnic.errorprone.utils.ConflictDetection;
 
 /** A {@link BugChecker} that flags non-canonical JUnit method declarations. */
 // XXX: Consider introducing a class-level check that enforces that test classes:

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

@@ -7,8 +7,8 @@ import static com.google.errorprone.matchers.ChildMultiMatcher.MatchType.AT_LEAS
 import static com.google.errorprone.matchers.Matchers.annotations;
 import static com.google.errorprone.matchers.Matchers.anyOf;
 import static com.google.errorprone.matchers.Matchers.isType;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
-import static tech.picnic.errorprone.bugpatterns.util.MoreMatchers.hasMetaAnnotation;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.MoreMatchers.hasMetaAnnotation;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;
@@ -23,7 +23,7 @@ import com.google.errorprone.matchers.MultiMatcher;
 import com.google.errorprone.matchers.MultiMatcher.MultiMatchResult;
 import com.sun.source.tree.AnnotationTree;
 import com.sun.source.tree.MethodTree;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags nullary {@link

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

@@ -19,9 +19,9 @@ import static com.google.errorprone.matchers.Matchers.staticMethod;
 import static com.google.errorprone.matchers.Matchers.toType;
 import static java.util.function.Predicate.not;
 import static java.util.stream.Collectors.joining;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
-import static tech.picnic.errorprone.bugpatterns.util.MoreJUnitMatchers.HAS_METHOD_SOURCE;
-import static tech.picnic.errorprone.bugpatterns.util.MoreJUnitMatchers.getMethodSourceFactoryNames;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.MoreJUnitMatchers.HAS_METHOD_SOURCE;
+import static tech.picnic.errorprone.utils.MoreJUnitMatchers.getMethodSourceFactoryNames;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.ImmutableList;
@@ -58,7 +58,7 @@ import java.util.stream.IntStream;
 import java.util.stream.LongStream;
 import java.util.stream.Stream;
 import org.jspecify.annotations.Nullable;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags JUnit tests with a {@link

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

@@ -7,7 +7,7 @@ import static com.google.errorprone.BugPattern.StandardTags.STYLE;
 import static java.util.Comparator.comparing;
 import static java.util.Comparator.naturalOrder;
 import static java.util.stream.Collectors.joining;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.base.Splitter;
@@ -42,9 +42,9 @@ import java.util.Set;
 import java.util.stream.Stream;
 import javax.inject.Inject;
 import org.jspecify.annotations.Nullable;
-import tech.picnic.errorprone.bugpatterns.util.AnnotationAttributeMatcher;
-import tech.picnic.errorprone.bugpatterns.util.Flags;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.AnnotationAttributeMatcher;
+import tech.picnic.errorprone.utils.Flags;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags annotation array listings which aren't sorted lexicographically.

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

@@ -7,7 +7,7 @@ import static com.google.errorprone.BugPattern.StandardTags.STYLE;
 import static com.sun.tools.javac.code.TypeAnnotations.AnnotationType.DECLARATION;
 import static com.sun.tools.javac.code.TypeAnnotations.AnnotationType.TYPE;
 import static java.util.Comparator.comparing;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.base.VerifyException;
@@ -28,7 +28,7 @@ import com.sun.tools.javac.code.TypeAnnotations.AnnotationType;
 import java.util.Comparator;
 import java.util.List;
 import org.jspecify.annotations.Nullable;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags annotations that are not lexicographically sorted.

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

@@ -9,7 +9,7 @@ import static com.google.errorprone.matchers.Matchers.isSameType;
 import static com.google.errorprone.matchers.Matchers.isVariable;
 import static com.google.errorprone.matchers.Matchers.not;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;
@@ -25,7 +25,7 @@ import com.sun.source.tree.MethodInvocationTree;
 import com.sun.source.tree.Tree;
 import com.sun.source.tree.VariableTree;
 import java.util.List;
-import tech.picnic.errorprone.bugpatterns.util.MoreASTHelpers;
+import tech.picnic.errorprone.utils.MoreASTHelpers;
 
 /**
  * A {@link BugChecker} that flags the use of {@link org.mockito.Mockito#mock(Class)} and {@link

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

@@ -4,7 +4,7 @@ import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.Iterables;
@@ -18,7 +18,7 @@ import com.google.errorprone.matchers.Matcher;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MethodInvocationTree;
 import java.util.List;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags method invocations for which all arguments are wrapped using

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

@@ -4,7 +4,7 @@ import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.BugPattern.StandardTags.PERFORMANCE;
 import static com.google.errorprone.matchers.method.MethodMatchers.staticMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;

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

@@ -3,11 +3,11 @@ package tech.picnic.errorprone.bugpatterns;
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
 import static com.google.errorprone.BugPattern.StandardTags.FRAGILE_CODE;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
-import static tech.picnic.errorprone.bugpatterns.util.MoreMatchers.isSubTypeOf;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.generic;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.raw;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.subOf;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.MoreMatchers.isSubTypeOf;
+import static tech.picnic.errorprone.utils.MoreTypes.generic;
+import static tech.picnic.errorprone.utils.MoreTypes.raw;
+import static tech.picnic.errorprone.utils.MoreTypes.subOf;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;

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

@@ -6,13 +6,13 @@ import static com.google.errorprone.BugPattern.StandardTags.FRAGILE_CODE;
 import static com.google.errorprone.matchers.Matchers.typePredicateMatcher;
 import static com.google.errorprone.predicates.TypePredicates.allOf;
 import static com.google.errorprone.predicates.TypePredicates.not;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypePredicates.hasTypeParameter;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypePredicates.isSubTypeOf;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.generic;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.raw;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.subOf;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.type;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.MoreTypePredicates.hasTypeParameter;
+import static tech.picnic.errorprone.utils.MoreTypePredicates.isSubTypeOf;
+import static tech.picnic.errorprone.utils.MoreTypes.generic;
+import static tech.picnic.errorprone.utils.MoreTypes.raw;
+import static tech.picnic.errorprone.utils.MoreTypes.subOf;
+import static tech.picnic.errorprone.utils.MoreTypes.type;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;

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

@@ -5,7 +5,7 @@ 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.instanceMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;
@@ -20,7 +20,7 @@ import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MethodInvocationTree;
 import java.util.function.BiFunction;
 import reactor.core.publisher.Mono;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags {@link Mono} operations that are known to be vacuous, given that

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

@@ -4,7 +4,7 @@ import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.BugPattern.StandardTags.STYLE;
 import static tech.picnic.errorprone.bugpatterns.StaticImport.STATIC_IMPORT_CANDIDATE_MEMBERS;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.auto.value.AutoValue;
@@ -33,9 +33,10 @@ import java.time.Clock;
 import java.time.ZoneOffset;
 import java.util.Collections;
 import java.util.Locale;
+import java.util.Optional;
 import java.util.regex.Pattern;
 import org.jspecify.annotations.Nullable;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags static imports of type members that should *not* be statically
@@ -71,7 +72,9 @@ public final class NonStaticImport extends BugChecker implements CompilationUnit
           Strings.class.getCanonicalName(),
           VisitorState.class.getCanonicalName(),
           ZoneOffset.class.getCanonicalName(),
-          "com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode");
+          "com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode",
+          "reactor.core.publisher.Flux",
+          "reactor.core.publisher.Mono");
 
   /**
    * Type members that should never be statically imported.
@@ -103,6 +106,7 @@ public final class NonStaticImport extends BugChecker implements CompilationUnit
               "sort",
               "swap")
           .put(Locale.class.getCanonicalName(), "ROOT")
+          .put(Optional.class.getCanonicalName(), "empty")
           .putAll(Pattern.class.getCanonicalName(), "compile", "matches", "quote")
           .put(Predicates.class.getCanonicalName(), "contains")
           .put("org.springframework.http.MediaType", "ALL")
@@ -125,7 +129,6 @@ public final class NonStaticImport extends BugChecker implements CompilationUnit
           "builder",
           "copyOf",
           "create",
-          "empty",
           "from",
           "getDefaultInstance",
           "INSTANCE",
@@ -136,10 +139,8 @@ public final class NonStaticImport extends BugChecker implements CompilationUnit
           "newBuilder",
           "newInstance",
           "of",
-          "ONE",
           "parse",
-          "valueOf",
-          "ZERO");
+          "valueOf");
 
   /** Instantiates a new {@link NonStaticImport} instance. */
   public NonStaticImport() {}

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

@@ -7,7 +7,7 @@ import static com.google.errorprone.matchers.Matchers.anyOf;
 import static com.google.errorprone.matchers.method.MethodMatchers.instanceMethod;
 import static com.google.errorprone.matchers.method.MethodMatchers.staticMethod;
 import static java.util.stream.Collectors.joining;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.base.VerifyException;
@@ -33,7 +33,7 @@ import java.util.Comparator;
 import java.util.Optional;
 import java.util.function.Function;
 import java.util.stream.Stream;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags {@code Comparator#comparing*} invocations that can be replaced

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

@@ -15,7 +15,7 @@ import static com.google.errorprone.matchers.Matchers.isSubtypeOf;
 import static com.google.errorprone.matchers.Matchers.not;
 import static com.google.errorprone.matchers.method.MethodMatchers.instanceMethod;
 import static com.google.errorprone.matchers.method.MethodMatchers.staticMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.base.Preconditions;
@@ -34,6 +34,7 @@ import com.google.errorprone.fixes.SuggestedFix;
 import com.google.errorprone.matchers.Description;
 import com.google.errorprone.matchers.Matcher;
 import com.google.errorprone.suppliers.Suppliers;
+import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.BinaryTree;
 import com.sun.source.tree.CompoundAssignmentTree;
 import com.sun.source.tree.ExpressionTree;
@@ -53,9 +54,9 @@ import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Stream;
 import javax.inject.Inject;
-import tech.picnic.errorprone.bugpatterns.util.Flags;
-import tech.picnic.errorprone.bugpatterns.util.MethodMatcherFactory;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.Flags;
+import tech.picnic.errorprone.utils.MethodMatcherFactory;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /** A {@link BugChecker} that flags redundant explicit string conversions. */
 @AutoService(BugChecker.class)
@@ -361,7 +362,7 @@ public final class RedundantStringConversion extends BugChecker
     return Optional.of(methodInvocation.getMethodSelect())
         .filter(methodSelect -> methodSelect.getKind() == Kind.MEMBER_SELECT)
         .map(methodSelect -> ((MemberSelectTree) methodSelect).getExpression())
-        .filter(expr -> !"super".equals(SourceCode.treeToString(expr, state)));
+        .filter(expr -> !ASTHelpers.isSuper(expr));
   }
 
   private static Optional<ExpressionTree> trySimplifyUnaryMethod(

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

@@ -11,7 +11,7 @@ import static com.google.errorprone.matchers.Matchers.isSameType;
 import static com.google.errorprone.matchers.Matchers.isType;
 import static com.google.errorprone.matchers.Matchers.methodHasParameters;
 import static com.google.errorprone.matchers.Matchers.not;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;
@@ -73,7 +73,9 @@ public final class RequestMappingAnnotation extends BugChecker implements Method
                           isType(ANN_PACKAGE_PREFIX + "RequestBody"),
                           isType(ANN_PACKAGE_PREFIX + "RequestHeader"),
                           isType(ANN_PACKAGE_PREFIX + "RequestParam"),
-                          isType(ANN_PACKAGE_PREFIX + "RequestPart"))),
+                          isType(ANN_PACKAGE_PREFIX + "RequestPart"),
+                          isType(
+                              "org.springframework.security.core.annotation.CurrentSecurityContext"))),
                   isSameType(InputStream.class.getCanonicalName()),
                   isSameType(Locale.class.getCanonicalName()),
                   isSameType(TimeZone.class.getCanonicalName()),

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

@@ -11,7 +11,7 @@ import static com.google.errorprone.matchers.Matchers.anyOf;
 import static com.google.errorprone.matchers.Matchers.isSubtypeOf;
 import static com.google.errorprone.matchers.Matchers.isType;
 import static com.google.errorprone.matchers.Matchers.not;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.ImmutableCollection;
@@ -28,7 +28,7 @@ import com.google.errorprone.suppliers.Suppliers;
 import com.sun.source.tree.Tree;
 import com.sun.source.tree.VariableTree;
 import javax.inject.Inject;
-import tech.picnic.errorprone.bugpatterns.util.Flags;
+import tech.picnic.errorprone.utils.Flags;
 
 /** A {@link BugChecker} that flags {@code @RequestParam} parameters with an unsupported type. */
 @AutoService(BugChecker.class)

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/Slf4jLogStatement.java

@@ -6,7 +6,7 @@ import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
 import static com.google.errorprone.BugPattern.StandardTags.LIKELY_ERROR;
 import static com.google.errorprone.matchers.Matchers.isSubtypeOf;
 import static com.google.errorprone.matchers.method.MethodMatchers.instanceMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.base.Splitter;
@@ -23,7 +23,7 @@ import com.sun.source.tree.MethodInvocationTree;
 import com.sun.source.tree.Tree.Kind;
 import java.util.List;
 import java.util.Optional;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /** A {@link BugChecker} that flags SLF4J usages that are likely to be in error. */
 // XXX: The special-casing of Throwable applies only to SLF4J 1.6.0+; see

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

@@ -6,7 +6,7 @@ import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
 import static java.util.function.Predicate.not;
 import static java.util.stream.Collectors.joining;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.base.VerifyException;
@@ -27,8 +27,8 @@ import com.sun.source.tree.MemberSelectTree;
 import com.sun.source.tree.NewArrayTree;
 import com.sun.source.tree.Tree.Kind;
 import java.util.Optional;
-import tech.picnic.errorprone.bugpatterns.util.AnnotationAttributeMatcher;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.AnnotationAttributeMatcher;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags {@code @RequestMapping} annotations that can be written more

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

@@ -6,7 +6,7 @@ import static com.google.errorprone.BugPattern.StandardTags.STYLE;
 import static java.util.Objects.requireNonNull;
 import static tech.picnic.errorprone.bugpatterns.NonStaticImport.NON_STATIC_IMPORT_CANDIDATE_IDENTIFIERS;
 import static tech.picnic.errorprone.bugpatterns.NonStaticImport.NON_STATIC_IMPORT_CANDIDATE_MEMBERS;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.annotations.VisibleForTesting;
@@ -132,7 +132,7 @@ public final class StaticImport extends BugChecker implements MemberSelectTreeMa
           "org.springframework.http.MediaType",
           "org.testng.Assert",
           "reactor.function.TupleUtils",
-          "tech.picnic.errorprone.bugpatterns.util.MoreTypes");
+          "tech.picnic.errorprone.utils.MoreTypes");
 
   /**
    * Type members that should be statically imported.

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

@@ -4,7 +4,7 @@ import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
 import static com.google.errorprone.matchers.method.MethodMatchers.staticMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.base.Splitter;
@@ -28,7 +28,7 @@ import java.util.Formattable;
 import java.util.Iterator;
 import java.util.List;
 import org.jspecify.annotations.Nullable;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags {@link String#format(String, Object...)} invocations which can be

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

@@ -10,7 +10,7 @@ import static com.google.errorprone.matchers.Matchers.instanceMethod;
 import static com.google.errorprone.matchers.Matchers.isSubtypeOf;
 import static com.google.errorprone.matchers.Matchers.not;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;

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

@@ -17,7 +17,7 @@ final class CanonicalClassNameUsageTest {
             "import static com.google.errorprone.matchers.Matchers.instanceMethod;",
             "",
             "import com.google.errorprone.VisitorState;",
-            "import tech.picnic.errorprone.bugpatterns.util.MoreTypes;",
+            "import tech.picnic.errorprone.utils.MoreTypes;",
             "",
             "class A {",
             "  void m(VisitorState state) {",
@@ -54,7 +54,7 @@ final class CanonicalClassNameUsageTest {
             "import static com.google.errorprone.matchers.Matchers.instanceMethod;",
             "",
             "import com.google.errorprone.BugPattern;",
-            "import tech.picnic.errorprone.bugpatterns.util.MoreTypes;",
+            "import tech.picnic.errorprone.utils.MoreTypes;",
             "",
             "class A {",
             "  void m() {",
@@ -67,7 +67,7 @@ final class CanonicalClassNameUsageTest {
             "import static com.google.errorprone.matchers.Matchers.instanceMethod;",
             "",
             "import com.google.errorprone.BugPattern;",
-            "import tech.picnic.errorprone.bugpatterns.util.MoreTypes;",
+            "import tech.picnic.errorprone.utils.MoreTypes;",
             "",
             "class A {",
             "  void m() {",

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

@@ -75,6 +75,8 @@ final class ExplicitEnumOrderingTest {
             "    Ordering.explicit(IsoEra.BCE, SOURCE, RetentionPolicy.CLASS);",
             "    // BUG: Diagnostic contains: RetentionPolicy.SOURCE, IsoEra.BCE",
             "    Ordering.explicit(CLASS, RUNTIME, CE);",
+            "",
+            "    Ordering.explicit(BCE, null, CE);",
             "  }",
             "}")
         .doTest();

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

@@ -65,6 +65,8 @@ final class NonStaticImportTest {
             "// BUG: Diagnostic contains:",
             "import static java.util.Optional.empty;",
             "import static pkg.A.WithMethodThatIsSelectivelyFlagged.list;",
+            "// BUG: Diagnostic contains:",
+            "import static reactor.core.publisher.Flux.just;",
             "",
             "import com.google.common.collect.ImmutableList;",
             "import com.google.common.collect.ImmutableSet;",
@@ -72,7 +74,7 @@ final class NonStaticImportTest {
             "import java.time.ZoneOffset;",
             "import java.util.Locale;",
             "import java.util.Map;",
-            "import pkg.A.Wrapper.ZERO;",
+            "import pkg.A.Wrapper.INSTANCE;",
             "",
             "class A {",
             "  private Integer MIN_VALUE = 12;",
@@ -90,9 +92,10 @@ final class NonStaticImportTest {
             "    Locale english = ENGLISH;",
             "    Locale root = ROOT;",
             "    empty();",
+            "    just();",
             "",
             "    list();",
-            "    new ZERO();",
+            "    new INSTANCE();",
             "  }",
             "",
             "  static final class WithMethodThatIsSelectivelyFlagged {",
@@ -102,7 +105,7 @@ final class NonStaticImportTest {
             "  }",
             "",
             "  static final class Wrapper {",
-            "    static final class ZERO {}",
+            "    static final class INSTANCE {}",
             "  }",
             "}")
         .doTest();

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

@@ -16,6 +16,7 @@ final class RequestMappingAnnotationTest {
             "import java.util.Locale;",
             "import java.util.TimeZone;",
             "import org.springframework.http.HttpMethod;",
+            "import org.springframework.security.core.annotation.CurrentSecurityContext;",
             "import org.springframework.ui.Model;",
             "import org.springframework.validation.BindingResult;",
             "import org.springframework.web.bind.annotation.DeleteMapping;",
@@ -63,6 +64,10 @@ final class RequestMappingAnnotationTest {
             "  A properRequestPart(@RequestPart String part);",
             "",
             "  @RequestMapping",
+            "  A properCurrentSecurityContext(",
+            "      @CurrentSecurityContext(expression = \"authentication.name\") String user);",
+            "",
+            "  @RequestMapping",
             "  A properInputStream(InputStream input);",
             "",
             "  @RequestMapping",

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

@@ -47,6 +47,7 @@ final class StaticImportTest {
             "import com.google.common.collect.ImmutableSet;",
             "import com.google.errorprone.refaster.ImportPolicy;",
             "import com.google.errorprone.refaster.annotation.UseImportPolicy;",
+            "import com.mongodb.client.model.Filters;",
             "import java.nio.charset.StandardCharsets;",
             "import java.time.ZoneOffset;",
             "import java.util.Optional;",
@@ -99,6 +100,8 @@ final class StaticImportTest {
             "    // BUG: Diagnostic contains:",
             "    MediaType t2 = MediaType.APPLICATION_JSON;",
             "",
+            "    // BUG: Diagnostic contains:",
+            "    Filters.empty();",
             "    Optional.empty();",
             "",
             "    // BUG: Diagnostic contains:",

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

@@ -17,6 +17,8 @@ import java.time.temporal.ChronoUnit;
 import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 
 final class TimeRulesTest implements RefasterRuleCollectionTestCase {
+  private static final ZonedDateTime ZONED_DATE_TIME = Instant.EPOCH.atZone(ZoneOffset.UTC);
+
   @Override
   public ImmutableSet<Object> elidedTypesAndStaticImports() {
     return ImmutableSet.of(ChronoUnit.class);
@@ -220,4 +222,385 @@ final class TimeRulesTest implements RefasterRuleCollectionTestCase {
         Period.ofYears(0),
         Period.of(0, 0, 0));
   }
+
+  ImmutableSet<LocalDate> testLocalDatePlusDays() {
+    return ImmutableSet.of(
+        LocalDate.EPOCH.plus(1L, ChronoUnit.DAYS), LocalDate.EPOCH.plus(Period.ofDays(1)));
+  }
+
+  ImmutableSet<LocalDate> testLocalDatePlusWeeks() {
+    return ImmutableSet.of(
+        LocalDate.EPOCH.plus(1L, ChronoUnit.WEEKS), LocalDate.EPOCH.plus(Period.ofWeeks(1)));
+  }
+
+  ImmutableSet<LocalDate> testLocalDatePlusMonths() {
+    return ImmutableSet.of(
+        LocalDate.EPOCH.plus(1L, ChronoUnit.MONTHS), LocalDate.EPOCH.plus(Period.ofMonths(1)));
+  }
+
+  ImmutableSet<LocalDate> testLocalDatePlusYears() {
+    return ImmutableSet.of(
+        LocalDate.EPOCH.plus(1L, ChronoUnit.YEARS), LocalDate.EPOCH.plus(Period.ofYears(1)));
+  }
+
+  ImmutableSet<LocalDate> testLocalDateMinusDays() {
+    return ImmutableSet.of(
+        LocalDate.EPOCH.minus(1L, ChronoUnit.DAYS), LocalDate.EPOCH.minus(Period.ofDays(1)));
+  }
+
+  ImmutableSet<LocalDate> testLocalDateMinusWeeks() {
+    return ImmutableSet.of(
+        LocalDate.EPOCH.minus(1L, ChronoUnit.WEEKS), LocalDate.EPOCH.minus(Period.ofWeeks(1)));
+  }
+
+  ImmutableSet<LocalDate> testLocalDateMinusMonths() {
+    return ImmutableSet.of(
+        LocalDate.EPOCH.minus(1L, ChronoUnit.MONTHS), LocalDate.EPOCH.minus(Period.ofMonths(1)));
+  }
+
+  ImmutableSet<LocalDate> testLocalDateMinusYears() {
+    return ImmutableSet.of(
+        LocalDate.EPOCH.minus(1L, ChronoUnit.YEARS), LocalDate.EPOCH.minus(Period.ofYears(1)));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimePlusNanos() {
+    return ImmutableSet.of(
+        LocalTime.NOON.plus(1L, ChronoUnit.NANOS), LocalTime.NOON.plus(Duration.ofNanos(1)));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimePlusSeconds() {
+    return ImmutableSet.of(
+        LocalTime.NOON.plus(1L, ChronoUnit.SECONDS), LocalTime.NOON.plus(Duration.ofSeconds(1)));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimePlusMinutes() {
+    return ImmutableSet.of(
+        LocalTime.NOON.plus(1L, ChronoUnit.MINUTES), LocalTime.NOON.plus(Duration.ofMinutes(1)));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimePlusHours() {
+    return ImmutableSet.of(
+        LocalTime.NOON.plus(1L, ChronoUnit.HOURS), LocalTime.NOON.plus(Duration.ofHours(1)));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimeMinusNanos() {
+    return ImmutableSet.of(
+        LocalTime.NOON.minus(1L, ChronoUnit.NANOS), LocalTime.NOON.minus(Duration.ofNanos(1)));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimeMinusSeconds() {
+    return ImmutableSet.of(
+        LocalTime.NOON.minus(1L, ChronoUnit.SECONDS), LocalTime.NOON.minus(Duration.ofSeconds(1)));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimeMinusMinutes() {
+    return ImmutableSet.of(
+        LocalTime.NOON.minus(1L, ChronoUnit.MINUTES), LocalTime.NOON.minus(Duration.ofMinutes(1)));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimeMinusHours() {
+    return ImmutableSet.of(
+        LocalTime.NOON.minus(1L, ChronoUnit.HOURS), LocalTime.NOON.minus(Duration.ofHours(1)));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimePlusNanos() {
+    return ImmutableSet.of(
+        OffsetTime.MIN.plus(1L, ChronoUnit.NANOS), OffsetTime.MIN.plus(Duration.ofNanos(1)));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimePlusSeconds() {
+    return ImmutableSet.of(
+        OffsetTime.MIN.plus(1L, ChronoUnit.SECONDS), OffsetTime.MIN.plus(Duration.ofSeconds(1)));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimePlusMinutes() {
+    return ImmutableSet.of(
+        OffsetTime.MIN.plus(1L, ChronoUnit.MINUTES), OffsetTime.MIN.plus(Duration.ofMinutes(1)));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimePlusHours() {
+    return ImmutableSet.of(
+        OffsetTime.MIN.plus(1L, ChronoUnit.HOURS), OffsetTime.MIN.plus(Duration.ofHours(1)));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimeMinusNanos() {
+    return ImmutableSet.of(
+        OffsetTime.MAX.minus(1L, ChronoUnit.NANOS), OffsetTime.MAX.minus(Duration.ofNanos(1)));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimeMinusSeconds() {
+    return ImmutableSet.of(
+        OffsetTime.MAX.minus(1L, ChronoUnit.SECONDS), OffsetTime.MAX.minus(Duration.ofSeconds(1)));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimeMinusMinutes() {
+    return ImmutableSet.of(
+        OffsetTime.MAX.minus(1L, ChronoUnit.MINUTES), OffsetTime.MAX.minus(Duration.ofMinutes(1)));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimeMinusHours() {
+    return ImmutableSet.of(
+        OffsetTime.MAX.minus(1L, ChronoUnit.HOURS), OffsetTime.MAX.minus(Duration.ofHours(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusNanos() {
+    return ImmutableSet.of(
+        LocalDateTime.MIN.plus(1L, ChronoUnit.NANOS), LocalDateTime.MIN.plus(Duration.ofNanos(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusSeconds() {
+    return ImmutableSet.of(
+        LocalDateTime.MIN.plus(1L, ChronoUnit.SECONDS),
+        LocalDateTime.MIN.plus(Duration.ofSeconds(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusMinutes() {
+    return ImmutableSet.of(
+        LocalDateTime.MIN.plus(1L, ChronoUnit.MINUTES),
+        LocalDateTime.MIN.plus(Duration.ofMinutes(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusHours() {
+    return ImmutableSet.of(
+        LocalDateTime.MIN.plus(1L, ChronoUnit.HOURS), LocalDateTime.MIN.plus(Duration.ofHours(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusDays() {
+    return ImmutableSet.of(
+        LocalDateTime.MIN.plus(1L, ChronoUnit.DAYS), LocalDateTime.MIN.plus(Period.ofDays(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusWeeks() {
+    return ImmutableSet.of(
+        LocalDateTime.MIN.plus(1L, ChronoUnit.WEEKS), LocalDateTime.MIN.plus(Period.ofWeeks(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusMonths() {
+    return ImmutableSet.of(
+        LocalDateTime.MIN.plus(1L, ChronoUnit.MONTHS), LocalDateTime.MIN.plus(Period.ofMonths(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusYears() {
+    return ImmutableSet.of(
+        LocalDateTime.MIN.plus(1L, ChronoUnit.YEARS), LocalDateTime.MIN.plus(Period.ofYears(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusNanos() {
+    return ImmutableSet.of(
+        LocalDateTime.MAX.minus(1L, ChronoUnit.NANOS),
+        LocalDateTime.MAX.minus(Duration.ofNanos(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusSeconds() {
+    return ImmutableSet.of(
+        LocalDateTime.MAX.minus(1L, ChronoUnit.SECONDS),
+        LocalDateTime.MAX.minus(Duration.ofSeconds(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusMinutes() {
+    return ImmutableSet.of(
+        LocalDateTime.MAX.minus(1L, ChronoUnit.MINUTES),
+        LocalDateTime.MAX.minus(Duration.ofMinutes(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusHours() {
+    return ImmutableSet.of(
+        LocalDateTime.MAX.minus(1L, ChronoUnit.HOURS),
+        LocalDateTime.MAX.minus(Duration.ofHours(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusDays() {
+    return ImmutableSet.of(
+        LocalDateTime.MAX.minus(1L, ChronoUnit.DAYS), LocalDateTime.MAX.minus(Period.ofDays(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusWeeks() {
+    return ImmutableSet.of(
+        LocalDateTime.MAX.minus(1L, ChronoUnit.WEEKS), LocalDateTime.MAX.minus(Period.ofWeeks(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusMonths() {
+    return ImmutableSet.of(
+        LocalDateTime.MAX.minus(1L, ChronoUnit.MONTHS),
+        LocalDateTime.MAX.minus(Period.ofMonths(1)));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusYears() {
+    return ImmutableSet.of(
+        LocalDateTime.MAX.minus(1L, ChronoUnit.YEARS), LocalDateTime.MAX.minus(Period.ofYears(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusNanos() {
+    return ImmutableSet.of(
+        OffsetDateTime.MIN.plus(1L, ChronoUnit.NANOS),
+        OffsetDateTime.MIN.plus(Duration.ofNanos(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusSeconds() {
+    return ImmutableSet.of(
+        OffsetDateTime.MIN.plus(1L, ChronoUnit.SECONDS),
+        OffsetDateTime.MIN.plus(Duration.ofSeconds(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusMinutes() {
+    return ImmutableSet.of(
+        OffsetDateTime.MIN.plus(1L, ChronoUnit.MINUTES),
+        OffsetDateTime.MIN.plus(Duration.ofMinutes(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusHours() {
+    return ImmutableSet.of(
+        OffsetDateTime.MIN.plus(1L, ChronoUnit.HOURS),
+        OffsetDateTime.MIN.plus(Duration.ofHours(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusDays() {
+    return ImmutableSet.of(
+        OffsetDateTime.MIN.plus(1L, ChronoUnit.DAYS), OffsetDateTime.MIN.plus(Period.ofDays(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusWeeks() {
+    return ImmutableSet.of(
+        OffsetDateTime.MIN.plus(1L, ChronoUnit.WEEKS), OffsetDateTime.MIN.plus(Period.ofWeeks(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusMonths() {
+    return ImmutableSet.of(
+        OffsetDateTime.MIN.plus(1L, ChronoUnit.MONTHS),
+        OffsetDateTime.MIN.plus(Period.ofMonths(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusYears() {
+    return ImmutableSet.of(
+        OffsetDateTime.MIN.plus(1L, ChronoUnit.YEARS), OffsetDateTime.MIN.plus(Period.ofYears(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusNanos() {
+    return ImmutableSet.of(
+        OffsetDateTime.MAX.minus(1L, ChronoUnit.NANOS),
+        OffsetDateTime.MAX.minus(Duration.ofNanos(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusSeconds() {
+    return ImmutableSet.of(
+        OffsetDateTime.MAX.minus(1L, ChronoUnit.SECONDS),
+        OffsetDateTime.MAX.minus(Duration.ofSeconds(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusMinutes() {
+    return ImmutableSet.of(
+        OffsetDateTime.MAX.minus(1L, ChronoUnit.MINUTES),
+        OffsetDateTime.MAX.minus(Duration.ofMinutes(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusHours() {
+    return ImmutableSet.of(
+        OffsetDateTime.MAX.minus(1L, ChronoUnit.HOURS),
+        OffsetDateTime.MAX.minus(Duration.ofHours(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusDays() {
+    return ImmutableSet.of(
+        OffsetDateTime.MAX.minus(1L, ChronoUnit.DAYS), OffsetDateTime.MAX.minus(Period.ofDays(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusWeeks() {
+    return ImmutableSet.of(
+        OffsetDateTime.MAX.minus(1L, ChronoUnit.WEEKS),
+        OffsetDateTime.MAX.minus(Period.ofWeeks(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusMonths() {
+    return ImmutableSet.of(
+        OffsetDateTime.MAX.minus(1L, ChronoUnit.MONTHS),
+        OffsetDateTime.MAX.minus(Period.ofMonths(1)));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusYears() {
+    return ImmutableSet.of(
+        OffsetDateTime.MAX.minus(1L, ChronoUnit.YEARS),
+        OffsetDateTime.MAX.minus(Period.ofYears(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusNanos() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.plus(1L, ChronoUnit.NANOS), ZONED_DATE_TIME.plus(Duration.ofNanos(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusSeconds() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.plus(1L, ChronoUnit.SECONDS), ZONED_DATE_TIME.plus(Duration.ofSeconds(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusMinutes() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.plus(1L, ChronoUnit.MINUTES), ZONED_DATE_TIME.plus(Duration.ofMinutes(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusHours() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.plus(1L, ChronoUnit.HOURS), ZONED_DATE_TIME.plus(Duration.ofHours(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusDays() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.plus(1L, ChronoUnit.DAYS), ZONED_DATE_TIME.plus(Period.ofDays(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusWeeks() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.plus(1L, ChronoUnit.WEEKS), ZONED_DATE_TIME.plus(Period.ofWeeks(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusMonths() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.plus(1L, ChronoUnit.MONTHS), ZONED_DATE_TIME.plus(Period.ofMonths(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusYears() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.plus(1L, ChronoUnit.YEARS), ZONED_DATE_TIME.plus(Period.ofYears(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusNanos() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.minus(1L, ChronoUnit.NANOS), ZONED_DATE_TIME.minus(Duration.ofNanos(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusSeconds() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.minus(1L, ChronoUnit.SECONDS),
+        ZONED_DATE_TIME.minus(Duration.ofSeconds(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusMinutes() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.minus(1L, ChronoUnit.MINUTES),
+        ZONED_DATE_TIME.minus(Duration.ofMinutes(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusHours() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.minus(1L, ChronoUnit.HOURS), ZONED_DATE_TIME.minus(Duration.ofHours(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusDays() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.minus(1L, ChronoUnit.DAYS), ZONED_DATE_TIME.minus(Period.ofDays(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusWeeks() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.minus(1L, ChronoUnit.WEEKS), ZONED_DATE_TIME.minus(Period.ofWeeks(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusMonths() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.minus(1L, ChronoUnit.MONTHS), ZONED_DATE_TIME.minus(Period.ofMonths(1)));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusYears() {
+    return ImmutableSet.of(
+        ZONED_DATE_TIME.minus(1L, ChronoUnit.YEARS), ZONED_DATE_TIME.minus(Period.ofYears(1)));
+  }
 }

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

@@ -17,6 +17,8 @@ import java.time.temporal.ChronoUnit;
 import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 
 final class TimeRulesTest implements RefasterRuleCollectionTestCase {
+  private static final ZonedDateTime ZONED_DATE_TIME = Instant.EPOCH.atZone(ZoneOffset.UTC);
+
   @Override
   public ImmutableSet<Object> elidedTypesAndStaticImports() {
     return ImmutableSet.of(ChronoUnit.class);
@@ -201,4 +203,292 @@ final class TimeRulesTest implements RefasterRuleCollectionTestCase {
   ImmutableSet<Period> testZeroPeriod() {
     return ImmutableSet.of(Period.ZERO, Period.ZERO, Period.ZERO, Period.ZERO, Period.ZERO);
   }
+
+  ImmutableSet<LocalDate> testLocalDatePlusDays() {
+    return ImmutableSet.of(LocalDate.EPOCH.plusDays(1L), LocalDate.EPOCH.plusDays(1));
+  }
+
+  ImmutableSet<LocalDate> testLocalDatePlusWeeks() {
+    return ImmutableSet.of(LocalDate.EPOCH.plusWeeks(1L), LocalDate.EPOCH.plusWeeks(1));
+  }
+
+  ImmutableSet<LocalDate> testLocalDatePlusMonths() {
+    return ImmutableSet.of(LocalDate.EPOCH.plusMonths(1L), LocalDate.EPOCH.plusMonths(1));
+  }
+
+  ImmutableSet<LocalDate> testLocalDatePlusYears() {
+    return ImmutableSet.of(LocalDate.EPOCH.plusYears(1L), LocalDate.EPOCH.plusYears(1));
+  }
+
+  ImmutableSet<LocalDate> testLocalDateMinusDays() {
+    return ImmutableSet.of(LocalDate.EPOCH.minusDays(1L), LocalDate.EPOCH.minusDays(1));
+  }
+
+  ImmutableSet<LocalDate> testLocalDateMinusWeeks() {
+    return ImmutableSet.of(LocalDate.EPOCH.minusWeeks(1L), LocalDate.EPOCH.minusWeeks(1));
+  }
+
+  ImmutableSet<LocalDate> testLocalDateMinusMonths() {
+    return ImmutableSet.of(LocalDate.EPOCH.minusMonths(1L), LocalDate.EPOCH.minusMonths(1));
+  }
+
+  ImmutableSet<LocalDate> testLocalDateMinusYears() {
+    return ImmutableSet.of(LocalDate.EPOCH.minusYears(1L), LocalDate.EPOCH.minusYears(1));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimePlusNanos() {
+    return ImmutableSet.of(LocalTime.NOON.plusNanos(1L), LocalTime.NOON.plusNanos(1));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimePlusSeconds() {
+    return ImmutableSet.of(LocalTime.NOON.plusSeconds(1L), LocalTime.NOON.plusSeconds(1));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimePlusMinutes() {
+    return ImmutableSet.of(LocalTime.NOON.plusMinutes(1L), LocalTime.NOON.plusMinutes(1));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimePlusHours() {
+    return ImmutableSet.of(LocalTime.NOON.plusHours(1L), LocalTime.NOON.plusHours(1));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimeMinusNanos() {
+    return ImmutableSet.of(LocalTime.NOON.minusNanos(1L), LocalTime.NOON.minusNanos(1));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimeMinusSeconds() {
+    return ImmutableSet.of(LocalTime.NOON.minusSeconds(1L), LocalTime.NOON.minusSeconds(1));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimeMinusMinutes() {
+    return ImmutableSet.of(LocalTime.NOON.minusMinutes(1L), LocalTime.NOON.minusMinutes(1));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimeMinusHours() {
+    return ImmutableSet.of(LocalTime.NOON.minusHours(1L), LocalTime.NOON.minusHours(1));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimePlusNanos() {
+    return ImmutableSet.of(OffsetTime.MIN.plusNanos(1L), OffsetTime.MIN.plusNanos(1));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimePlusSeconds() {
+    return ImmutableSet.of(OffsetTime.MIN.plusSeconds(1L), OffsetTime.MIN.plusSeconds(1));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimePlusMinutes() {
+    return ImmutableSet.of(OffsetTime.MIN.plusMinutes(1L), OffsetTime.MIN.plusMinutes(1));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimePlusHours() {
+    return ImmutableSet.of(OffsetTime.MIN.plusHours(1L), OffsetTime.MIN.plusHours(1));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimeMinusNanos() {
+    return ImmutableSet.of(OffsetTime.MAX.minusNanos(1L), OffsetTime.MAX.minusNanos(1));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimeMinusSeconds() {
+    return ImmutableSet.of(OffsetTime.MAX.minusSeconds(1L), OffsetTime.MAX.minusSeconds(1));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimeMinusMinutes() {
+    return ImmutableSet.of(OffsetTime.MAX.minusMinutes(1L), OffsetTime.MAX.minusMinutes(1));
+  }
+
+  ImmutableSet<OffsetTime> testOffsetTimeMinusHours() {
+    return ImmutableSet.of(OffsetTime.MAX.minusHours(1L), OffsetTime.MAX.minusHours(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusNanos() {
+    return ImmutableSet.of(LocalDateTime.MIN.plusNanos(1L), LocalDateTime.MIN.plusNanos(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusSeconds() {
+    return ImmutableSet.of(LocalDateTime.MIN.plusSeconds(1L), LocalDateTime.MIN.plusSeconds(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusMinutes() {
+    return ImmutableSet.of(LocalDateTime.MIN.plusMinutes(1L), LocalDateTime.MIN.plusMinutes(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusHours() {
+    return ImmutableSet.of(LocalDateTime.MIN.plusHours(1L), LocalDateTime.MIN.plusHours(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusDays() {
+    return ImmutableSet.of(LocalDateTime.MIN.plusDays(1L), LocalDateTime.MIN.plusDays(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusWeeks() {
+    return ImmutableSet.of(LocalDateTime.MIN.plusWeeks(1L), LocalDateTime.MIN.plusWeeks(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusMonths() {
+    return ImmutableSet.of(LocalDateTime.MIN.plusMonths(1L), LocalDateTime.MIN.plusMonths(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimePlusYears() {
+    return ImmutableSet.of(LocalDateTime.MIN.plusYears(1L), LocalDateTime.MIN.plusYears(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusNanos() {
+    return ImmutableSet.of(LocalDateTime.MAX.minusNanos(1L), LocalDateTime.MAX.minusNanos(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusSeconds() {
+    return ImmutableSet.of(LocalDateTime.MAX.minusSeconds(1L), LocalDateTime.MAX.minusSeconds(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusMinutes() {
+    return ImmutableSet.of(LocalDateTime.MAX.minusMinutes(1L), LocalDateTime.MAX.minusMinutes(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusHours() {
+    return ImmutableSet.of(LocalDateTime.MAX.minusHours(1L), LocalDateTime.MAX.minusHours(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusDays() {
+    return ImmutableSet.of(LocalDateTime.MAX.minusDays(1L), LocalDateTime.MAX.minusDays(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusWeeks() {
+    return ImmutableSet.of(LocalDateTime.MAX.minusWeeks(1L), LocalDateTime.MAX.minusWeeks(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusMonths() {
+    return ImmutableSet.of(LocalDateTime.MAX.minusMonths(1L), LocalDateTime.MAX.minusMonths(1));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeMinusYears() {
+    return ImmutableSet.of(LocalDateTime.MAX.minusYears(1L), LocalDateTime.MAX.minusYears(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusNanos() {
+    return ImmutableSet.of(OffsetDateTime.MIN.plusNanos(1L), OffsetDateTime.MIN.plusNanos(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusSeconds() {
+    return ImmutableSet.of(OffsetDateTime.MIN.plusSeconds(1L), OffsetDateTime.MIN.plusSeconds(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusMinutes() {
+    return ImmutableSet.of(OffsetDateTime.MIN.plusMinutes(1L), OffsetDateTime.MIN.plusMinutes(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusHours() {
+    return ImmutableSet.of(OffsetDateTime.MIN.plusHours(1L), OffsetDateTime.MIN.plusHours(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusDays() {
+    return ImmutableSet.of(OffsetDateTime.MIN.plusDays(1L), OffsetDateTime.MIN.plusDays(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusWeeks() {
+    return ImmutableSet.of(OffsetDateTime.MIN.plusWeeks(1L), OffsetDateTime.MIN.plusWeeks(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusMonths() {
+    return ImmutableSet.of(OffsetDateTime.MIN.plusMonths(1L), OffsetDateTime.MIN.plusMonths(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimePlusYears() {
+    return ImmutableSet.of(OffsetDateTime.MIN.plusYears(1L), OffsetDateTime.MIN.plusYears(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusNanos() {
+    return ImmutableSet.of(OffsetDateTime.MAX.minusNanos(1L), OffsetDateTime.MAX.minusNanos(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusSeconds() {
+    return ImmutableSet.of(OffsetDateTime.MAX.minusSeconds(1L), OffsetDateTime.MAX.minusSeconds(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusMinutes() {
+    return ImmutableSet.of(OffsetDateTime.MAX.minusMinutes(1L), OffsetDateTime.MAX.minusMinutes(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusHours() {
+    return ImmutableSet.of(OffsetDateTime.MAX.minusHours(1L), OffsetDateTime.MAX.minusHours(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusDays() {
+    return ImmutableSet.of(OffsetDateTime.MAX.minusDays(1L), OffsetDateTime.MAX.minusDays(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusWeeks() {
+    return ImmutableSet.of(OffsetDateTime.MAX.minusWeeks(1L), OffsetDateTime.MAX.minusWeeks(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusMonths() {
+    return ImmutableSet.of(OffsetDateTime.MAX.minusMonths(1L), OffsetDateTime.MAX.minusMonths(1));
+  }
+
+  ImmutableSet<OffsetDateTime> testOffsetDateTimeMinusYears() {
+    return ImmutableSet.of(OffsetDateTime.MAX.minusYears(1L), OffsetDateTime.MAX.minusYears(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusNanos() {
+    return ImmutableSet.of(ZONED_DATE_TIME.plusNanos(1L), ZONED_DATE_TIME.plusNanos(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusSeconds() {
+    return ImmutableSet.of(ZONED_DATE_TIME.plusSeconds(1L), ZONED_DATE_TIME.plusSeconds(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusMinutes() {
+    return ImmutableSet.of(ZONED_DATE_TIME.plusMinutes(1L), ZONED_DATE_TIME.plusMinutes(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusHours() {
+    return ImmutableSet.of(ZONED_DATE_TIME.plusHours(1L), ZONED_DATE_TIME.plusHours(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusDays() {
+    return ImmutableSet.of(ZONED_DATE_TIME.plusDays(1L), ZONED_DATE_TIME.plusDays(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusWeeks() {
+    return ImmutableSet.of(ZONED_DATE_TIME.plusWeeks(1L), ZONED_DATE_TIME.plusWeeks(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusMonths() {
+    return ImmutableSet.of(ZONED_DATE_TIME.plusMonths(1L), ZONED_DATE_TIME.plusMonths(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimePlusYears() {
+    return ImmutableSet.of(ZONED_DATE_TIME.plusYears(1L), ZONED_DATE_TIME.plusYears(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusNanos() {
+    return ImmutableSet.of(ZONED_DATE_TIME.minusNanos(1L), ZONED_DATE_TIME.minusNanos(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusSeconds() {
+    return ImmutableSet.of(ZONED_DATE_TIME.minusSeconds(1L), ZONED_DATE_TIME.minusSeconds(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusMinutes() {
+    return ImmutableSet.of(ZONED_DATE_TIME.minusMinutes(1L), ZONED_DATE_TIME.minusMinutes(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusHours() {
+    return ImmutableSet.of(ZONED_DATE_TIME.minusHours(1L), ZONED_DATE_TIME.minusHours(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusDays() {
+    return ImmutableSet.of(ZONED_DATE_TIME.minusDays(1L), ZONED_DATE_TIME.minusDays(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusWeeks() {
+    return ImmutableSet.of(ZONED_DATE_TIME.minusWeeks(1L), ZONED_DATE_TIME.minusWeeks(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusMonths() {
+    return ImmutableSet.of(ZONED_DATE_TIME.minusMonths(1L), ZONED_DATE_TIME.minusMonths(1));
+  }
+
+  ImmutableSet<ZonedDateTime> testZonedDateTimeMinusYears() {
+    return ImmutableSet.of(ZONED_DATE_TIME.minusYears(1L), ZONED_DATE_TIME.minusYears(1));
+  }
 }

error-prone-experimental/README.md

@@ -0,0 +1,6 @@
+# Experimental Error Prone checks
+
+This module contains Error Prone checks that are currently under development or
+evaluation. These checks may be works-in-progress or have uncertain impact on
+code. Having this module allows for controlled experimentation and refinement
+before integration into production environments.

error-prone-experimental/pom.xml

@@ -0,0 +1,61 @@
+<?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>0.14.1-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>error-prone-experimental</artifactId>
+
+    <name>Picnic :: Error Prone Support :: Experimental</name>
+    <description>Experimental Error Prone checks.</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_check_api</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>com.google.auto.service</groupId>
+            <artifactId>auto-service-annotations</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <!-- XXX: Explicitly declared as a workaround for
+        https://github.com/pitest/pitest-junit5-plugin/issues/105. -->
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

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

@@ -1,10 +1,10 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.experimental.bugpatterns;
 
 import static com.google.common.collect.ImmutableList.toImmutableList;
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.BugPattern.StandardTags.STYLE;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.base.VerifyException;
@@ -37,8 +37,6 @@ import javax.lang.model.element.Name;
 
 /**
  * A {@link BugChecker} that flags lambda expressions that can be replaced with method references.
- *
- * @see IsInstanceLambdaUsage
  */
 // XXX: Other custom expressions we could rewrite:
 // - `a -> "str" + a` to `"str"::concat`. But only if `str` is provably non-null.
@@ -54,7 +52,8 @@ import javax.lang.model.element.Name;
 // Palantir's `LambdaMethodReference` check seems to suffer a similar issue at this time.
 // XXX: Expressions of the form `i -> SomeType.class.isInstance(i)` are not replaced; fix that using
 // a suitable generalization.
-// XXX: Consider folding the `IsInstanceLambdaUsage` check into this class.
+// XXX: Consider folding the `IsInstanceLambdaUsage` check of the `error-prone-contrib` module into
+// this class.
 @AutoService(BugChecker.class)
 @BugPattern(
     summary = "Prefer method references over lambda expressions",

error-prone-experimental/src/test/java/tech/picnic/errorprone/experimental/bugpatterns/MethodReferenceUsageTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.experimental.bugpatterns;
 
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
 import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;

error-prone-guidelines/README.md

@@ -0,0 +1,5 @@
+# Error Prone Support coding guidelines
+
+This module provides Error Prone checks that describe and suggest coding
+guidelines for both Error Prone checks and Refaster rules. These rules are only
+meant to be applied to Error Prone Support itself.

error-prone-guidelines/pom.xml

@@ -0,0 +1,119 @@
+<?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>0.14.1-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>error-prone-guidelines</artifactId>
+
+    <name>Picnic :: Error Prone Support :: Guidelines</name>
+    <description>Coding guidelines for the Error Prone Support project.</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>documentation-support</artifactId>
+            <!-- This dependency is declared only as a hint to Maven that
+            compilation depends on it; see the `maven-compiler-plugin`'s
+            `annotationProcessorPaths` configuration below. -->
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>error-prone-utils</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.google.auto.service</groupId>
+            <artifactId>auto-service-annotations</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.google.googlejavaformat</groupId>
+            <artifactId>google-java-format</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.jspecify</groupId>
+            <artifactId>jspecify</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <!-- XXX: Explicitly declared as a workaround for
+        https://github.com/pitest/pitest-junit5-plugin/issues/105. -->
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-compiler-plugin</artifactId>
+                    <configuration>
+                        <annotationProcessorPaths combine.children="append">
+                            <!-- XXX: Drop the version declarations once
+                            properly supported. See
+                            https://youtrack.jetbrains.com/issue/IDEA-342187. -->
+                            <path>
+                                <groupId>${project.groupId}</groupId>
+                                <artifactId>documentation-support</artifactId>
+                                <version>${project.version}</version>
+                            </path>
+                        </annotationProcessorPaths>
+                        <compilerArgs combine.children="append">
+                            <arg>-Xplugin:DocumentationGenerator -XoutputDirectory=${project.build.directory}/docs</arg>
+                        </compilerArgs>
+                    </configuration>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
+</project>

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

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
@@ -7,7 +7,7 @@ import static com.google.errorprone.matchers.Matchers.allOf;
 import static com.google.errorprone.matchers.Matchers.not;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
 import static com.google.errorprone.matchers.Matchers.toType;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.ImmutableSet;
@@ -27,7 +27,7 @@ import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MethodInvocationTree;
 import com.sun.tools.javac.code.Type;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags unnecessarily nested usage of methods that implement an
@@ -36,6 +36,8 @@ import tech.picnic.errorprone.bugpatterns.util.SourceCode;
  * <p>The arguments to such methods can be flattened without affecting semantics, while making the
  * code more readable.
  */
+// XXX: Move this check to the `error-prone-contrib` module once it also covers non-Error Prone
+// methods.
 @AutoService(BugChecker.class)
 @BugPattern(
     summary =

error-prone-guidelines/src/main/java/tech/picnic/errorprone/guidelines/bugpatterns/ErrorProneRuntimeClasspath.java

@@ -1,11 +1,11 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.BugPattern.StandardTags.FRAGILE_CODE;
 import static com.google.errorprone.matchers.Matchers.instanceMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.ImmutableSet;
@@ -28,7 +28,7 @@ import com.sun.tools.javac.code.Symbol;
 import com.sun.tools.javac.code.Symbol.ClassSymbol;
 import com.sun.tools.javac.util.Constants;
 import java.util.regex.Pattern;
-import tech.picnic.errorprone.bugpatterns.util.ThirdPartyLibrary;
+import tech.picnic.errorprone.utils.ThirdPartyLibrary;
 
 /**
  * A {@link BugChecker} that flags literal strings in Error Prone Support code that represent the

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

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
@@ -7,7 +7,7 @@ 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 java.util.stream.Collectors.joining;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.base.Splitter;

error-prone-guidelines/src/main/java/tech/picnic/errorprone/guidelines/bugpatterns/RefasterAnyOfUsage.java

@@ -1,10 +1,10 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
 import static com.google.errorprone.matchers.method.MethodMatchers.staticMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;
@@ -17,7 +17,7 @@ import com.google.errorprone.matchers.Matcher;
 import com.google.errorprone.refaster.Refaster;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MethodInvocationTree;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags unnecessary {@link Refaster#anyOf(Object[])} usages.

error-prone-guidelines/src/main/java/tech/picnic/errorprone/guidelines/bugpatterns/RefasterMethodParameterOrder.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import static com.google.common.collect.ImmutableList.toImmutableList;
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
@@ -8,7 +8,7 @@ import static com.google.errorprone.matchers.Matchers.anyOf;
 import static com.google.errorprone.matchers.Matchers.hasAnnotation;
 import static java.util.Comparator.comparing;
 import static java.util.stream.Collectors.toCollection;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.common.collect.ImmutableList;
@@ -38,7 +38,7 @@ import java.util.Set;
 import java.util.stream.Stream;
 import javax.lang.model.element.Name;
 import org.jspecify.annotations.Nullable;
-import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+import tech.picnic.errorprone.utils.SourceCode;
 
 /**
  * A {@link BugChecker} that flags Refaster methods with a non-canonical parameter order.

error-prone-guidelines/src/main/java/tech/picnic/errorprone/guidelines/bugpatterns/RefasterRuleModifiers.java

@@ -1,11 +1,11 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.BugPattern.StandardTags.STYLE;
 import static com.google.errorprone.matchers.Matchers.anyOf;
 import static com.google.errorprone.matchers.Matchers.hasAnnotation;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;

error-prone-guidelines/src/main/java/tech/picnic/errorprone/guidelines/bugpatterns/UnqualifiedSuggestedFixImport.java

@@ -1,10 +1,10 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
 import static com.google.errorprone.BugPattern.StandardTags.FRAGILE_CODE;
 import static com.google.errorprone.matchers.Matchers.instanceMethod;
-import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
 import com.google.errorprone.BugPattern;

error-prone-guidelines/src/main/java/tech/picnic/errorprone/guidelines/bugpatterns/package-info.java

@@ -0,0 +1,4 @@
+/** Error Prone Support coding guidelines. */
+@com.google.errorprone.annotations.CheckReturnValue
+@org.jspecify.annotations.NullMarked
+package tech.picnic.errorprone.guidelines.bugpatterns;

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

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
 import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;

error-prone-guidelines/src/test/java/tech/picnic/errorprone/guidelines/bugpatterns/ErrorProneRuntimeClasspathTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
 import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
@@ -47,6 +47,7 @@ final class ErrorProneRuntimeClasspathTest {
             "    m(\"com.google.errorprone.NonExistent\");",
             "    m(\"com.google.common.NonExistent.toString\");",
             "    m(\"java.lang.NonExistent\");",
+            "    m(\"com.google.common.collect.ImmutableEnumSet\");",
             "    // BUG: Diagnostic matches: USE_CLASS_REFERENCE",
             "    m(\"com.google.errorprone.BugPattern\");",
             "    // BUG: Diagnostic matches: USE_CLASS_REFERENCE",

error-prone-guidelines/src/test/java/tech/picnic/errorprone/guidelines/bugpatterns/ErrorProneTestHelperSourceFormatTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
 import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
@@ -14,13 +14,13 @@ final class ErrorProneTestHelperSourceFormatTest {
             "import com.google.errorprone.BugCheckerRefactoringTestHelper;",
             "import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;",
             "import com.google.errorprone.CompilationTestHelper;",
-            "import tech.picnic.errorprone.bugpatterns.EmptyMethod;",
+            "import tech.picnic.errorprone.guidelines.bugpatterns.RefasterAnyOfUsage;",
             "",
             "class A {",
             "  private final CompilationTestHelper compilationTestHelper =",
-            "      CompilationTestHelper.newInstance(EmptyMethod.class, getClass());",
+            "      CompilationTestHelper.newInstance(RefasterAnyOfUsage.class, getClass());",
             "  private final BugCheckerRefactoringTestHelper refactoringTestHelper =",
-            "      BugCheckerRefactoringTestHelper.newInstance(EmptyMethod.class, getClass());",
+            "      BugCheckerRefactoringTestHelper.newInstance(RefasterAnyOfUsage.class, getClass());",
             "",
             "  void m() {",
             "    compilationTestHelper",
@@ -63,13 +63,13 @@ final class ErrorProneTestHelperSourceFormatTest {
             "import com.google.errorprone.BugCheckerRefactoringTestHelper;",
             "import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;",
             "import com.google.errorprone.CompilationTestHelper;",
-            "import tech.picnic.errorprone.bugpatterns.EmptyMethod;",
+            "import tech.picnic.errorprone.guidelines.bugpatterns.RefasterAnyOfUsage;",
             "",
             "class A {",
             "  private final CompilationTestHelper compilationTestHelper =",
-            "      CompilationTestHelper.newInstance(EmptyMethod.class, getClass());",
+            "      CompilationTestHelper.newInstance(RefasterAnyOfUsage.class, getClass());",
             "  private final BugCheckerRefactoringTestHelper refactoringTestHelper =",
-            "      BugCheckerRefactoringTestHelper.newInstance(EmptyMethod.class, getClass());",
+            "      BugCheckerRefactoringTestHelper.newInstance(RefasterAnyOfUsage.class, getClass());",
             "",
             "  void m() {",
             "    compilationTestHelper",
@@ -105,13 +105,13 @@ final class ErrorProneTestHelperSourceFormatTest {
             "import com.google.errorprone.BugCheckerRefactoringTestHelper;",
             "import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;",
             "import com.google.errorprone.CompilationTestHelper;",
-            "import tech.picnic.errorprone.bugpatterns.EmptyMethod;",
+            "import tech.picnic.errorprone.guidelines.bugpatterns.RefasterAnyOfUsage;",
             "",
             "class A {",
             "  private final CompilationTestHelper compilationTestHelper =",
-            "      CompilationTestHelper.newInstance(EmptyMethod.class, getClass());",
+            "      CompilationTestHelper.newInstance(RefasterAnyOfUsage.class, getClass());",
             "  private final BugCheckerRefactoringTestHelper refactoringTestHelper =",
-            "      BugCheckerRefactoringTestHelper.newInstance(EmptyMethod.class, getClass());",
+            "      BugCheckerRefactoringTestHelper.newInstance(RefasterAnyOfUsage.class, getClass());",
             "",
             "  void m() {",
             "    compilationTestHelper",

error-prone-guidelines/src/test/java/tech/picnic/errorprone/guidelines/bugpatterns/RefasterAnyOfUsageTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
 import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;

error-prone-guidelines/src/test/java/tech/picnic/errorprone/guidelines/bugpatterns/RefasterMethodParameterOrderTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
 import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;

error-prone-guidelines/src/test/java/tech/picnic/errorprone/guidelines/bugpatterns/RefasterRuleModifiersTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
 import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;

error-prone-guidelines/src/test/java/tech/picnic/errorprone/guidelines/bugpatterns/UnqualifiedSuggestedFixImportTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns;
+package tech.picnic.errorprone.guidelines.bugpatterns;
 
 import com.google.errorprone.CompilationTestHelper;
 import org.junit.jupiter.api.Test;

error-prone-utils/pom.xml

@@ -0,0 +1,76 @@
+<?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>0.14.1-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>error-prone-utils</artifactId>
+
+    <name>Picnic :: Error Prone Support :: Utils</name>
+    <description>Provides utility classes for Error Prone development.</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_test_helpers</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.projectreactor</groupId>
+            <artifactId>reactor-core</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.jspecify</groupId>
+            <artifactId>jspecify</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <!-- XXX: Explicitly declared as a workaround for
+        https://github.com/pitest/pitest-junit5-plugin/issues/105. -->
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-params</artifactId>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+</project>

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/AnnotationAttributeMatcher.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.HashMultimap;

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/ConflictDetection.java

@@ -1,6 +1,6 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
-import static tech.picnic.errorprone.bugpatterns.util.JavaKeywords.isValidIdentifier;
+import static tech.picnic.errorprone.utils.JavaKeywords.isValidIdentifier;
 
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.util.ASTHelpers;

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/Documentation.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 /** Utility class providing documentation-related code. */
 public final class Documentation {

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/Flags.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import com.google.common.collect.ImmutableList;
 import com.google.errorprone.ErrorProneFlags;

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/JavaKeywords.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Sets;

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/MethodMatcherFactory.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.collect.ImmutableSet.toImmutableSet;

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/MoreASTHelpers.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.collect.ImmutableList.toImmutableList;
@@ -15,8 +15,7 @@ import java.util.Optional;
 /**
  * A collection of helper methods for working with the AST.
  *
- * <p>These methods are additions to the ones found in {@link
- * com.google.errorprone.util.ASTHelpers}.
+ * <p>These methods are additions to the ones found in {@link ASTHelpers}.
  */
 public final class MoreASTHelpers {
   private MoreASTHelpers() {}

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/MoreJUnitMatchers.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.google.common.collect.ImmutableList.toImmutableList;
 import static com.google.errorprone.matchers.ChildMultiMatcher.MatchType.AT_LEAST_ONE;
@@ -6,7 +6,7 @@ import static com.google.errorprone.matchers.Matchers.annotations;
 import static com.google.errorprone.matchers.Matchers.anyOf;
 import static com.google.errorprone.matchers.Matchers.isType;
 import static java.util.Objects.requireNonNullElse;
-import static tech.picnic.errorprone.bugpatterns.util.MoreMatchers.hasMetaAnnotation;
+import static tech.picnic.errorprone.utils.MoreMatchers.hasMetaAnnotation;
 
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/MoreMatchers.java

@@ -1,7 +1,7 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.google.errorprone.matchers.Matchers.typePredicateMatcher;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypePredicates.hasAnnotation;
+import static tech.picnic.errorprone.utils.MoreTypePredicates.hasAnnotation;
 
 import com.google.errorprone.matchers.Matcher;
 import com.google.errorprone.matchers.Matchers;

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/MoreTypePredicates.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.predicates.TypePredicate;

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/MoreTypes.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static java.util.stream.Collectors.toCollection;
 

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/SourceCode.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.sun.tools.javac.parser.Tokens.TokenKind.RPAREN;
 import static com.sun.tools.javac.util.Position.NOPOS;

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/ThirdPartyLibrary.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import com.google.common.collect.ImmutableList;
 import com.google.errorprone.VisitorState;
@@ -6,10 +6,13 @@ import com.google.errorprone.bugpatterns.BugChecker;
 import com.google.errorprone.suppliers.Supplier;
 import com.sun.tools.javac.code.ClassFinder;
 import com.sun.tools.javac.code.Source;
+import com.sun.tools.javac.code.Symbol;
 import com.sun.tools.javac.code.Symbol.CompletionFailure;
 import com.sun.tools.javac.code.Symbol.ModuleSymbol;
 import com.sun.tools.javac.code.Symtab;
+import com.sun.tools.javac.code.Type;
 import com.sun.tools.javac.util.Name;
+import javax.lang.model.element.Modifier;
 
 /**
  * Utility class that helps decide whether it is appropriate to introduce references to (well-known)
@@ -70,12 +73,12 @@ public enum ThirdPartyLibrary {
   /**
    * Tells whether the given fully qualified type is available on the current class path.
    *
-   * @param className The type of interest.
+   * @param typeName The type of interest.
    * @param state The context under consideration.
    * @return {@code true} iff it is okay to assume or create a dependency on this type.
    */
-  public static boolean canIntroduceUsage(String className, VisitorState state) {
-    return shouldIgnoreClasspath(state) || isKnownClass(className, state);
+  public static boolean canIntroduceUsage(String typeName, VisitorState state) {
+    return shouldIgnoreClasspath(state) || isKnownClass(typeName, state);
   }
 
   /**
@@ -84,11 +87,16 @@ public enum ThirdPartyLibrary {
    * <p>The {@link VisitorState}'s symbol table is consulted first. If the type has not yet been
    * loaded, then an attempt is made to do so.
    */
-  private static boolean isKnownClass(String className, VisitorState state) {
-    return state.getTypeFromString(className) != null || canLoadClass(className, state);
+  private static boolean isKnownClass(String typeName, VisitorState state) {
+    return isPublicClassInSymbolTable(typeName, state) || canLoadPublicClass(typeName, state);
   }
 
-  private static boolean canLoadClass(String className, VisitorState state) {
+  private static boolean isPublicClassInSymbolTable(String typeName, VisitorState state) {
+    Type type = state.getTypeFromString(typeName);
+    return type != null && isPublic(type.tsym);
+  }
+
+  private static boolean canLoadPublicClass(String typeName, VisitorState state) {
     ClassFinder classFinder = ClassFinder.instance(state.context);
     Symtab symtab = state.getSymtab();
     // XXX: Drop support for targeting Java 8 once the oldest supported JDK drops such support.
@@ -96,10 +104,9 @@ public enum ThirdPartyLibrary {
         Source.instance(state.context).compareTo(Source.JDK9) < 0
             ? symtab.noModule
             : symtab.unnamedModule;
-    Name binaryName = state.binaryNameFromClassname(className);
+    Name binaryName = state.binaryNameFromClassname(typeName);
     try {
-      classFinder.loadClass(module, binaryName);
-      return true;
+      return isPublic(classFinder.loadClass(module, binaryName));
     } catch (
         @SuppressWarnings("java:S1166" /* Not exceptional. */)
         CompletionFailure e) {
@@ -107,6 +114,11 @@ public enum ThirdPartyLibrary {
     }
   }
 
+  // XXX: Once we target JDK 14+, drop this method in favour of `Symbol#isPublic()`.
+  private static boolean isPublic(Symbol symbol) {
+    return symbol.getModifiers().contains(Modifier.PUBLIC);
+  }
+
   private static boolean shouldIgnoreClasspath(VisitorState state) {
     return state
         .errorProneOptions()

error-prone-utils/src/main/java/tech/picnic/errorprone/utils/package-info.java

@@ -1,4 +1,4 @@
 /** Auxiliary utilities for use by Error Prone checks. */
 @com.google.errorprone.annotations.CheckReturnValue
 @org.jspecify.annotations.NullMarked
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;

error-prone-utils/src/test/java/tech/picnic/errorprone/utils/AnnotationAttributeMatcherTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 

error-prone-utils/src/test/java/tech/picnic/errorprone/utils/ConflictDetectionTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
 

error-prone-utils/src/test/java/tech/picnic/errorprone/utils/FlagsTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.params.provider.Arguments.arguments;

error-prone-utils/src/test/java/tech/picnic/errorprone/utils/JavaKeywordsTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.params.provider.Arguments.arguments;

error-prone-utils/src/test/java/tech/picnic/errorprone/utils/MethodMatcherFactoryTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;

error-prone-utils/src/test/java/tech/picnic/errorprone/utils/MoreASTHelpersTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
 

error-prone-utils/src/test/java/tech/picnic/errorprone/utils/MoreJUnitMatchersTest.java

@@ -1,10 +1,10 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
-import static tech.picnic.errorprone.bugpatterns.util.MoreJUnitMatchers.HAS_METHOD_SOURCE;
-import static tech.picnic.errorprone.bugpatterns.util.MoreJUnitMatchers.SETUP_OR_TEARDOWN_METHOD;
-import static tech.picnic.errorprone.bugpatterns.util.MoreJUnitMatchers.TEST_METHOD;
+import static tech.picnic.errorprone.utils.MoreJUnitMatchers.HAS_METHOD_SOURCE;
+import static tech.picnic.errorprone.utils.MoreJUnitMatchers.SETUP_OR_TEARDOWN_METHOD;
+import static tech.picnic.errorprone.utils.MoreJUnitMatchers.TEST_METHOD;
 
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;

error-prone-utils/src/test/java/tech/picnic/errorprone/utils/MoreMatchersTest.java

@@ -1,9 +1,9 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.generic;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.subOf;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.type;
+import static tech.picnic.errorprone.utils.MoreTypes.generic;
+import static tech.picnic.errorprone.utils.MoreTypes.subOf;
+import static tech.picnic.errorprone.utils.MoreTypes.type;
 
 import com.google.common.collect.ImmutableSet;
 import com.google.errorprone.BugPattern;

error-prone-utils/src/test/java/tech/picnic/errorprone/utils/MoreTypesTest.java

@@ -1,12 +1,12 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.generic;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.raw;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.subOf;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.superOf;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.type;
-import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.unbound;
+import static tech.picnic.errorprone.utils.MoreTypes.generic;
+import static tech.picnic.errorprone.utils.MoreTypes.raw;
+import static tech.picnic.errorprone.utils.MoreTypes.subOf;
+import static tech.picnic.errorprone.utils.MoreTypes.superOf;
+import static tech.picnic.errorprone.utils.MoreTypes.type;
+import static tech.picnic.errorprone.utils.MoreTypes.unbound;
 
 import com.google.common.collect.ImmutableSet;
 import com.google.errorprone.BugPattern;

error-prone-utils/src/test/java/tech/picnic/errorprone/utils/SourceCodeTest.java

@@ -1,4 +1,4 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
 

error-prone-utils/src/test/java/tech/picnic/errorprone/utils/ThirdPartyLibraryTest.java

@@ -1,9 +1,10 @@
-package tech.picnic.errorprone.bugpatterns.util;
+package tech.picnic.errorprone.utils;
 
 import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
 import static java.util.stream.Collectors.joining;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.errorprone.BugPattern;
 import com.google.errorprone.CompilationTestHelper;
 import com.google.errorprone.VisitorState;
@@ -20,7 +21,7 @@ import reactor.core.publisher.Flux;
 final class ThirdPartyLibraryTest {
   @Test
   void isIntroductionAllowed() {
-    CompilationTestHelper.newInstance(TestChecker.class, getClass())
+    CompilationTestHelper.newInstance(IsIntroductionAllowedTestChecker.class, getClass())
         .addSourceLines(
             "A.java",
             "// BUG: Diagnostic contains: ASSERTJ: true, GUAVA: true, REACTOR: true",
@@ -29,8 +30,8 @@ final class ThirdPartyLibraryTest {
   }
 
   @Test
-  void isIntroductionAllowedWitnessClassesInSymtab() {
-    CompilationTestHelper.newInstance(TestChecker.class, getClass())
+  void isIntroductionAllowedWitnessClassesInSymbolTable() {
+    CompilationTestHelper.newInstance(IsIntroductionAllowedTestChecker.class, getClass())
         .addSourceLines(
             "A.java",
             "import com.google.common.collect.ImmutableList;",
@@ -50,7 +51,7 @@ final class ThirdPartyLibraryTest {
 
   @Test
   void isIntroductionAllowedWitnessClassesPartiallyOnClassPath() {
-    CompilationTestHelper.newInstance(TestChecker.class, getClass())
+    CompilationTestHelper.newInstance(IsIntroductionAllowedTestChecker.class, getClass())
         .withClasspath(ImmutableList.class, Flux.class)
         .addSourceLines(
             "A.java",
@@ -61,7 +62,7 @@ final class ThirdPartyLibraryTest {
 
   @Test
   void isIntroductionAllowedWitnessClassesNotOnClassPath() {
-    CompilationTestHelper.newInstance(TestChecker.class, getClass())
+    CompilationTestHelper.newInstance(IsIntroductionAllowedTestChecker.class, getClass())
         .withClasspath()
         .addSourceLines(
             "A.java",
@@ -74,7 +75,7 @@ final class ThirdPartyLibraryTest {
   @ParameterizedTest
   @ValueSource(booleans = {true, false})
   void isIntroductionAllowedIgnoreClasspathCompat(boolean ignoreClassPath) {
-    CompilationTestHelper.newInstance(TestChecker.class, getClass())
+    CompilationTestHelper.newInstance(IsIntroductionAllowedTestChecker.class, getClass())
         .setArgs("-XepOpt:ErrorProneSupport:IgnoreClasspathCompat=" + ignoreClassPath)
         .withClasspath(ImmutableList.class, Flux.class)
         .addSourceLines(
@@ -86,12 +87,24 @@ final class ThirdPartyLibraryTest {
         .doTest();
   }
 
+  @Test
+  void canIntroduceUsage() {
+    CompilationTestHelper.newInstance(CanIntroduceUsageTestChecker.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "// BUG: Diagnostic contains: GUAVA_PUBLIC: true, GUAVA_PRIVATE: false, ERROR_PRONE_PUBLIC_NESTED:",
+            "// true",
+            "class A {}")
+        .doTest();
+  }
+
   /**
    * Flags classes with a diagnostics message that indicates, for each {@link ThirdPartyLibrary}
    * element, whether they can be used.
    */
   @BugPattern(severity = ERROR, summary = "Interacts with `ThirdPartyLibrary` for testing purposes")
-  public static final class TestChecker extends BugChecker implements ClassTreeMatcher {
+  public static final class IsIntroductionAllowedTestChecker extends BugChecker
+      implements ClassTreeMatcher {
     private static final long serialVersionUID = 1L;
 
     @Override
@@ -99,10 +112,39 @@ final class ThirdPartyLibraryTest {
       return buildDescription(tree)
           .setMessage(
               Arrays.stream(ThirdPartyLibrary.values())
+                  .map(lib -> lib.name() + ": " + lib.isIntroductionAllowed(state))
+                  .collect(joining(", ")))
+          .build();
+    }
+  }
+
+  /**
+   * Flags classes with a diagnostics message that indicates, for selected types, the result of
+   * {@link ThirdPartyLibrary#canIntroduceUsage(String, VisitorState)}.
+   */
+  @BugPattern(severity = ERROR, summary = "Interacts with `ThirdPartyLibrary` for testing purposes")
+  public static final class CanIntroduceUsageTestChecker extends BugChecker
+      implements ClassTreeMatcher {
+    private static final long serialVersionUID = 1L;
+    private static final ImmutableMap<String, String> TYPES =
+        ImmutableMap.of(
+            "GUAVA_PUBLIC",
+            ImmutableList.class.getCanonicalName(),
+            "GUAVA_PRIVATE",
+            "com.google.common.collect.ImmutableEnumSet",
+            "ERROR_PRONE_PUBLIC_NESTED",
+            "com.google.errorprone.BugCheckerRefactoringTestHelper.ExpectOutput");
+
+    @Override
+    public Description matchClass(ClassTree tree, VisitorState state) {
+      return buildDescription(tree)
+          .setMessage(
+              TYPES.entrySet().stream()
                   .map(
-                      lib ->
-                          String.join(
-                              ": ", lib.name(), String.valueOf(lib.isIntroductionAllowed(state))))
+                      e ->
+                          e.getKey()
+                              + ": "
+                              + ThirdPartyLibrary.canIntroduceUsage(e.getValue(), state))
                   .collect(joining(", ")))
           .build();
     }