Introduce ReturnValueUnused matcher for Refaster use

WIP:
1. As-is this isn't actually useful, because currently there's no way to
   express that a certain matcher should apply to a whole expression
   (rather than just a "free variable"/template parameter).
2. There are some XXXes.
3. Assuming (1) is resolved somehow, we should add at least one Refaster
   template demonstrating how this is used. Example transformation we'd
   want to be able to do in case the expression's return value is
   ignored: `flux.blockLast()` -> `flux.then().block()`.

.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;
@@ -53,9 +53,9 @@ 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)

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();
     }