Post rebase fixes

See:
- https://github.com/typetools/checker-framework/releases/tag/checker-framework-3.27.0
- https://github.com/typetools/checker-framework/compare/checker-framework-3.26.0...checker-framework-3.27.0

.github/workflows/build.yaml

@@ -7,10 +7,27 @@ permissions:
   contents: read
 jobs:
   build:
-    runs-on: ubuntu-22.04
     strategy:
       matrix:
-        jdk: [ 11.0.16, 17.0.4 ]
+        os: [ ubuntu-22.04 ]
+        jdk: [ 11.0.16, 17.0.4, 19 ]
+        distribution: [ temurin ]
+        experimental: [ false ]
+        include:
+          - os: macos-12
+            jdk: 17.0.4
+            distribution: temurin
+            experimental: false
+          - os: windows-2022
+            jdk: 17.0.4
+            distribution: temurin
+            experimental: false
+          - os: ubuntu-22.04
+            jdk: 20-ea
+            distribution: zulu
+            experimental: true
+    runs-on: ${{ matrix.os }}
+    continue-on-error: ${{ matrix.experimental }}
     steps:
         # We run the build twice for each supported JDK: once against the
         # original Error Prone release, using only Error Prone checks available
@@ -20,10 +37,10 @@ jobs:
       - name: Check out code
         uses: actions/checkout@v3.1.0
       - name: Set up JDK
-        uses: actions/setup-java@v3.5.1
+        uses: actions/setup-java@v3.6.0
         with:
           java-version: ${{ matrix.jdk }}
-          distribution: temurin
+          distribution: ${{ matrix.distribution }}
           cache: maven
       - name: Display build environment details
         run: mvn --version

.github/workflows/deploy-website.yaml

@@ -3,25 +3,22 @@ on:
   pull_request:
   push:
     branches: [ master, website ]
-permissions:
-  contents: read
-  id-token: write
-  pages: write
 concurrency:
-  group: pages
-  cancel-in-progress: true
+  group: ${{ github.workflow }}-${{ github.ref }}
 jobs:
   build:
+    permissions:
+      contents: read
     runs-on: ubuntu-22.04
     steps:
       - name: Check out code
         uses: actions/checkout@v3.1.0
-      - uses: ruby/setup-ruby@v1.117.0
+      - uses: ruby/setup-ruby@v1.120.0
         with:
           working-directory: ./website
           bundler-cache: true
       - name: Configure Github Pages
-        uses: actions/configure-pages@v2.1.1
+        uses: actions/configure-pages@v2.1.2
       - name: Generate documentation
         run: ./generate-docs.sh
       - name: Build website with Jekyll
@@ -39,6 +36,9 @@ jobs:
   deploy:
     if: github.ref == 'refs/heads/website'
     needs: build
+    permissions:
+      id-token: write
+      pages: write
     runs-on: ubuntu-22.04
     environment:
       name: github-pages
@@ -46,4 +46,4 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v1.2.1
+        uses: actions/deploy-pages@v1.2.2

README.md

@@ -20,6 +20,7 @@ loves Error Prone: producing high-quality and consistent Java
 code_][picnic-blog-ep-post].
 
 [![Maven Central][maven-central-badge]][maven-central-search]
+[![Reproducible Builds][reproducible-builds-badge]][reproducible-builds-report]
 [![GitHub Actions][github-actions-build-badge]][github-actions-build-master]
 [![License][license-badge]][license]
 [![PRs Welcome][pr-badge]][contributing]
@@ -119,16 +120,13 @@ code with Maven should yield two compiler warnings:
 ```sh
 $ mvn clean install
 ...
-[INFO] -------------------------------------------------------------
-[WARNING] COMPILATION WARNING :
-[INFO] -------------------------------------------------------------
-[WARNING] Example.java:[9,34] [tech.picnic.errorprone.refasterrules.BigDecimalRules.BigDecimalZero]
+[INFO] Example.java:[9,34] [Refaster Rule] BigDecimalRules.BigDecimalZero: Refactoring opportunity
+    (see https://error-prone.picnic.tech/refasterrules/BigDecimalRules#BigDecimalZero)
   Did you mean 'return BigDecimal.ZERO;'?
+...
 [WARNING] Example.java:[13,35] [IdentityConversion] This method invocation appears redundant; remove it or suppress this warning and add a comment explaining its purpose
     (see https://error-prone.picnic.tech/bugpatterns/IdentityConversion)
   Did you mean 'return set;' or '@SuppressWarnings("IdentityConversion") public ImmutableSet<Integer> getSet() {'?
-[INFO] 2 warnings
-[INFO] -------------------------------------------------------------
 ...
 ```
 
@@ -229,3 +227,5 @@ guidelines][contributing].
 [refaster]: https://errorprone.info/docs/refaster
 [refaster-rules-bigdecimal]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/BigDecimalRules.java
 [refaster-rules]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/
+[reproducible-builds-badge]: https://img.shields.io/badge/Reproducible_Builds-ok-success?labelColor=1e5b96
+[reproducible-builds-report]: https://github.com/jvm-repo-rebuild/reproducible-central/blob/master/content/tech/picnic/error-prone-support/error-prone-support/README.md

error-prone-contrib/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.3.1-SNAPSHOT</version>
+        <version>0.5.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>error-prone-contrib</artifactId>
@@ -64,11 +64,6 @@
             <artifactId>auto-service-annotations</artifactId>
             <scope>provided</scope>
         </dependency>
-        <dependency>
-            <groupId>com.google.code.findbugs</groupId>
-            <artifactId>jsr305</artifactId>
-            <scope>provided</scope>
-        </dependency>
         <dependency>
             <groupId>com.google.googlejavaformat</groupId>
             <artifactId>google-java-format</artifactId>
@@ -98,6 +93,11 @@
             <artifactId>reactor-adapter</artifactId>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>io.projectreactor.addons</groupId>
+            <artifactId>reactor-extra</artifactId>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>io.reactivex.rxjava2</groupId>
             <artifactId>rxjava</artifactId>
@@ -173,6 +173,11 @@
             <artifactId>slf4j-api</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-context</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-test</artifactId>

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

@@ -36,6 +36,9 @@ public final class AmbiguousJsonCreator extends BugChecker implements Annotation
   private static final Matcher<AnnotationTree> IS_JSON_CREATOR_ANNOTATION =
       isType("com.fasterxml.jackson.annotation.JsonCreator");
 
+  /** Instantiates a new {@link AmbiguousJsonCreator} instance. */
+  public AmbiguousJsonCreator() {}
+
   @Override
   public Description matchAnnotation(AnnotationTree tree, VisitorState state) {
     if (!IS_JSON_CREATOR_ANNOTATION.matches(tree, state)) {

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

@@ -44,6 +44,9 @@ public final class AssertJIsNull extends BugChecker implements MethodInvocationT
           argumentCount(1),
           argument(0, nullLiteral()));
 
+  /** Instantiates a new {@link AssertJIsNull} instance. */
+  public AssertJIsNull() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     if (!ASSERT_IS_EQUAL_TO_NULL.matches(tree, state)) {

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

@@ -38,6 +38,9 @@ public final class AutowiredConstructor extends BugChecker implements ClassTreeM
   private static final MultiMatcher<Tree, AnnotationTree> AUTOWIRED_ANNOTATION =
       annotations(AT_LEAST_ONE, isType("org.springframework.beans.factory.annotation.Autowired"));
 
+  /** Instantiates a new {@link AutowiredConstructor} instance. */
+  public AutowiredConstructor() {}
+
   @Override
   public Description matchClass(ClassTree tree, VisitorState state) {
     List<MethodTree> constructors = ASTHelpers.getConstructors(tree);

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

@@ -46,6 +46,9 @@ public final class CanonicalAnnotationSyntax extends BugChecker implements Annot
               CanonicalAnnotationSyntax::dropRedundantValueAttribute,
               CanonicalAnnotationSyntax::dropRedundantCurlies);
 
+  /** Instantiates a new {@link CanonicalAnnotationSyntax} instance. */
+  public CanonicalAnnotationSyntax() {}
+
   @Override
   public Description matchAnnotation(AnnotationTree tree, VisitorState state) {
     return FIX_FACTORIES.stream()

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

@@ -18,6 +18,7 @@ import com.google.errorprone.matchers.Matcher;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MethodInvocationTree;
 import java.util.stream.Collector;
+import tech.picnic.errorprone.bugpatterns.util.ThirdPartyLibrary;
 
 /**
  * A {@link BugChecker} that flags {@link Collector Collectors} that don't clearly express
@@ -45,9 +46,13 @@ public final class CollectorMutability extends BugChecker implements MethodInvoc
   private static final Matcher<ExpressionTree> SET_COLLECTOR =
       staticMethod().anyClass().named("toSet");
 
+  /** Instantiates a new {@link CollectorMutability} instance. */
+  public CollectorMutability() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
-    if (!COLLECTOR_METHOD.matches(tree, state)) {
+    if (!ThirdPartyLibrary.GUAVA.isIntroductionAllowed(state)
+        || !COLLECTOR_METHOD.matches(tree, state)) {
       return Description.NO_MATCH;
     }
 

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

@@ -38,6 +38,9 @@ public final class EmptyMethod extends BugChecker implements MethodTreeMatcher {
           AT_LEAST_ONE,
           anyOf(isType("java.lang.Override"), isType("org.aspectj.lang.annotation.Pointcut")));
 
+  /** Instantiates a new {@link EmptyMethod} instance. */
+  public EmptyMethod() {}
+
   @Override
   public Description matchMethod(MethodTree tree, VisitorState state) {
     if (tree.getBody() == null

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

@@ -72,6 +72,9 @@ public final class ErrorProneTestHelperSourceFormat extends BugChecker
           .onDescendantOf("com.google.errorprone.BugCheckerRefactoringTestHelper.ExpectOutput")
           .named("addOutputLines");
 
+  /** Instantiates a new {@link ErrorProneTestHelperSourceFormat} instance. */
+  public ErrorProneTestHelperSourceFormat() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     boolean isOutputSource = OUTPUT_SOURCE_ACCEPTING_METHOD.matches(tree, state);

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

@@ -46,6 +46,9 @@ public final class ExplicitEnumOrdering extends BugChecker implements MethodInvo
   private static final Matcher<ExpressionTree> EXPLICIT_ORDERING =
       staticMethod().onClass(Ordering.class.getName()).named("explicit");
 
+  /** Instantiates a new {@link ExplicitEnumOrdering} instance. */
+  public ExplicitEnumOrdering() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     if (!EXPLICIT_ORDERING.matches(tree, state)) {

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

@@ -5,6 +5,10 @@ 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 com.google.auto.service.AutoService;
 import com.google.common.collect.Iterables;
@@ -17,11 +21,14 @@ import com.google.errorprone.fixes.SuggestedFix;
 import com.google.errorprone.fixes.SuggestedFixes;
 import com.google.errorprone.matchers.Description;
 import com.google.errorprone.matchers.Matcher;
+import com.google.errorprone.suppliers.Supplier;
+import com.google.errorprone.suppliers.Suppliers;
+import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MemberReferenceTree;
 import com.sun.source.tree.MethodInvocationTree;
+import com.sun.tools.javac.code.Type;
 import java.util.function.Function;
-import java.util.function.Supplier;
 import reactor.core.publisher.Flux;
 
 /**
@@ -33,11 +40,12 @@ import reactor.core.publisher.Flux;
  * former interleaves values as they are emitted, yielding nondeterministic results. In most cases
  * {@link Flux#concatMap(Function)} should be preferred, as it produces consistent results and
  * avoids potentially saturating the thread pool on which subscription happens. If {@code
- * concatMap}'s single-subscription semantics are undesirable one should invoke a {@code flatMap} or
- * {@code flatMapSequential} overload with an explicit concurrency level.
+ * concatMap}'s sequential-subscription semantics are undesirable one should invoke a {@code
+ * flatMap} or {@code flatMapSequential} overload with an explicit concurrency level.
  *
- * <p>NB: The rarely-used overload {@link Flux#flatMap(Function, Function, Supplier)} is not flagged
- * by this check because there is no clear alternative to point to.
+ * <p>NB: The rarely-used overload {@link Flux#flatMap(Function, Function,
+ * java.util.function.Supplier)} is not flagged by this check because there is no clear alternative
+ * to point to.
  */
 @AutoService(BugChecker.class)
 @BugPattern(
@@ -52,11 +60,19 @@ public final class FluxFlatMapUsage extends BugChecker
     implements MethodInvocationTreeMatcher, MemberReferenceTreeMatcher {
   private static final long serialVersionUID = 1L;
   private static final String MAX_CONCURRENCY_ARG_NAME = "MAX_CONCURRENCY";
+  private static final Supplier<Type> FLUX =
+      Suppliers.typeFromString("reactor.core.publisher.Flux");
   private static final Matcher<ExpressionTree> FLUX_FLATMAP =
       instanceMethod()
-          .onDescendantOf("reactor.core.publisher.Flux")
+          .onDescendantOf(FLUX)
           .namedAnyOf("flatMap", "flatMapSequential")
           .withParameters(Function.class.getName());
+  private static final Supplier<Type> FLUX_OF_PUBLISHERS =
+      VisitorState.memoize(
+          generic(FLUX, subOf(generic(type("org.reactivestreams.Publisher"), unbound()))));
+
+  /** Instantiates a new {@link FluxFlatMapUsage} instance. */
+  public FluxFlatMapUsage() {}
 
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
@@ -64,14 +80,27 @@ public final class FluxFlatMapUsage extends BugChecker
       return Description.NO_MATCH;
     }
 
-    return buildDescription(tree)
-        .addFix(SuggestedFixes.renameMethodInvocation(tree, "concatMap", state))
-        .addFix(
-            SuggestedFix.builder()
-                .postfixWith(
-                    Iterables.getOnlyElement(tree.getArguments()), ", " + MAX_CONCURRENCY_ARG_NAME)
-                .build())
-        .build();
+    SuggestedFix serializationFix = SuggestedFixes.renameMethodInvocation(tree, "concatMap", state);
+    SuggestedFix concurrencyCapFix =
+        SuggestedFix.builder()
+            .postfixWith(
+                Iterables.getOnlyElement(tree.getArguments()), ", " + MAX_CONCURRENCY_ARG_NAME)
+            .build();
+
+    Description.Builder description = buildDescription(tree);
+
+    if (state.getTypes().isSubtype(ASTHelpers.getType(tree), FLUX_OF_PUBLISHERS.get(state))) {
+      /*
+       * Nested publishers may need to be subscribed to eagerly in order to avoid a deadlock, e.g.
+       * if they are produced by `Flux#groupBy`. In this case we suggest specifying an explicit
+       * concurrently bound, in favour of sequential subscriptions using `Flux#concatMap`.
+       */
+      description.addFix(concurrencyCapFix).addFix(serializationFix);
+    } else {
+      description.addFix(serializationFix).addFix(concurrencyCapFix);
+    }
+
+    return description.build();
   }
 
   @Override

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

@@ -32,7 +32,7 @@ import com.sun.source.util.SimpleTreeVisitor;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
-import javax.annotation.Nullable;
+import org.jspecify.nullness.Nullable;
 import tech.picnic.errorprone.bugpatterns.util.SourceCode;
 
 /**
@@ -129,6 +129,9 @@ public final class FormatStringConcatenation extends BugChecker
           .onDescendantOf("org.slf4j.Logger")
           .namedAnyOf("debug", "error", "info", "trace", "warn");
 
+  /** Instantiates a new {@link FormatStringConcatenation} instance. */
+  public FormatStringConcatenation() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     if (hasNonConstantStringConcatenationArgument(tree, 0, state)) {
@@ -204,7 +207,7 @@ public final class FormatStringConcatenation extends BugChecker
   }
 
   private static class ReplacementArgumentsConstructor
-      extends SimpleTreeVisitor<Void, VisitorState> {
+      extends SimpleTreeVisitor<@Nullable Void, VisitorState> {
     private final StringBuilder formatString = new StringBuilder();
     private final List<Tree> formatArguments = new ArrayList<>();
     private final String formatSpecifier;
@@ -213,9 +216,8 @@ public final class FormatStringConcatenation extends BugChecker
       this.formatSpecifier = formatSpecifier;
     }
 
-    @Nullable
     @Override
-    public Void visitBinary(BinaryTree tree, VisitorState state) {
+    public @Nullable Void visitBinary(BinaryTree tree, VisitorState state) {
       if (tree.getKind() == Kind.PLUS && isStringTyped(tree, state)) {
         tree.getLeftOperand().accept(this, state);
         tree.getRightOperand().accept(this, state);
@@ -226,15 +228,13 @@ public final class FormatStringConcatenation extends BugChecker
       return null;
     }
 
-    @Nullable
     @Override
-    public Void visitParenthesized(ParenthesizedTree tree, VisitorState state) {
+    public @Nullable Void visitParenthesized(ParenthesizedTree tree, VisitorState state) {
       return tree.getExpression().accept(this, state);
     }
 
-    @Nullable
     @Override
-    protected Void defaultAction(Tree tree, VisitorState state) {
+    protected @Nullable Void defaultAction(Tree tree, VisitorState state) {
       appendExpression(tree);
       return null;
     }

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

@@ -72,6 +72,9 @@ public final class IdentityConversion extends BugChecker implements MethodInvoca
               .namedAnyOf("concat", "firstWithSignal", "from", "merge"),
           staticMethod().onClass("reactor.core.publisher.Mono").namedAnyOf("from", "fromDirect"));
 
+  /** Instantiates a new {@link IdentityConversion} instance. */
+  public IdentityConversion() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     List<? extends ExpressionTree> arguments = tree.getArguments();

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

@@ -67,6 +67,9 @@ public final class ImmutablesSortedSetComparator extends BugChecker implements M
                   hasAnnotation("org.immutables.value.Value.NaturalOrder"),
                   hasAnnotation("org.immutables.value.Value.ReverseOrder"))));
 
+  /** Instantiates a new {@link ImmutablesSortedSetComparator} instance. */
+  public ImmutablesSortedSetComparator() {}
+
   @Override
   public Description matchMethod(MethodTree tree, VisitorState state) {
     if (!METHOD_LACKS_ANNOTATION.matches(tree, state)) {

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

@@ -0,0 +1,53 @@
+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 com.google.auto.service.AutoService;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.LambdaExpressionTreeMatcher;
+import com.google.errorprone.fixes.SuggestedFix;
+import com.google.errorprone.matchers.Description;
+import com.sun.source.tree.InstanceOfTree;
+import com.sun.source.tree.LambdaExpressionTree;
+import com.sun.source.tree.Tree.Kind;
+import tech.picnic.errorprone.bugpatterns.util.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.
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary = "Prefer `Class::isInstance` method reference over equivalent lambda expression",
+    link = BUG_PATTERNS_BASE_URL + "IsInstanceLambdaUsage",
+    linkType = CUSTOM,
+    severity = SUGGESTION,
+    tags = SIMPLIFICATION)
+public final class IsInstanceLambdaUsage extends BugChecker implements LambdaExpressionTreeMatcher {
+  private static final long serialVersionUID = 1L;
+
+  /** Instantiates a new {@link IsInstanceLambdaUsage} instance. */
+  public IsInstanceLambdaUsage() {}
+
+  @Override
+  public Description matchLambdaExpression(LambdaExpressionTree tree, VisitorState state) {
+    if (tree.getKind() != Kind.LAMBDA_EXPRESSION || tree.getBody().getKind() != Kind.INSTANCE_OF) {
+      return Description.NO_MATCH;
+    }
+
+    return describeMatch(
+        tree,
+        SuggestedFix.replace(
+            tree,
+            SourceCode.treeToString(((InstanceOfTree) tree.getBody()).getType(), state)
+                + ".class::isInstance"));
+  }
+}

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

@@ -79,6 +79,9 @@ public final class JUnitMethodDeclaration extends BugChecker implements MethodTr
               isType("org.junit.jupiter.api.BeforeAll"),
               isType("org.junit.jupiter.api.BeforeEach")));
 
+  /** Instantiates a new {@link JUnitMethodDeclaration} instance. */
+  public JUnitMethodDeclaration() {}
+
   @Override
   public Description matchMethod(MethodTree tree, VisitorState state) {
     if (HAS_UNMODIFIABLE_SIGNATURE.matches(tree, state)) {

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

@@ -40,7 +40,7 @@ import java.util.List;
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Stream;
-import javax.annotation.Nullable;
+import org.jspecify.nullness.Nullable;
 import tech.picnic.errorprone.bugpatterns.util.AnnotationAttributeMatcher;
 import tech.picnic.errorprone.bugpatterns.util.SourceCode;
 
@@ -82,7 +82,7 @@ public final class LexicographicalAnnotationAttributeListing extends BugChecker
 
   private final AnnotationAttributeMatcher matcher;
 
-  /** Instantiates the default {@link LexicographicalAnnotationAttributeListing}. */
+  /** Instantiates a default {@link LexicographicalAnnotationAttributeListing} instance. */
   public LexicographicalAnnotationAttributeListing() {
     this(ErrorProneFlags.empty());
   }
@@ -184,17 +184,15 @@ public final class LexicographicalAnnotationAttributeListing extends BugChecker
   private static ImmutableList<ImmutableList<String>> getStructure(ExpressionTree array) {
     ImmutableList.Builder<ImmutableList<String>> nodes = ImmutableList.builder();
 
-    new TreeScanner<Void, Void>() {
-      @Nullable
+    new TreeScanner<@Nullable Void, @Nullable Void>() {
       @Override
-      public Void visitIdentifier(IdentifierTree node, @Nullable Void unused) {
+      public @Nullable Void visitIdentifier(IdentifierTree node, @Nullable Void unused) {
         nodes.add(ImmutableList.of(node.getName().toString()));
         return super.visitIdentifier(node, unused);
       }
 
-      @Nullable
       @Override
-      public Void visitLiteral(LiteralTree node, @Nullable Void unused) {
+      public @Nullable Void visitLiteral(LiteralTree node, @Nullable Void unused) {
         Object value = ASTHelpers.constValue(node);
         nodes.add(
             value instanceof String
@@ -204,9 +202,8 @@ public final class LexicographicalAnnotationAttributeListing extends BugChecker
         return super.visitLiteral(node, unused);
       }
 
-      @Nullable
       @Override
-      public Void visitPrimitiveType(PrimitiveTypeTree node, @Nullable Void unused) {
+      public @Nullable Void visitPrimitiveType(PrimitiveTypeTree node, @Nullable Void unused) {
         nodes.add(ImmutableList.of(node.getPrimitiveTypeKind().toString()));
         return super.visitPrimitiveType(node, unused);
       }

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

@@ -4,10 +4,13 @@ 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 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 com.google.auto.service.AutoService;
+import com.google.common.base.VerifyException;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Streams;
 import com.google.errorprone.BugPattern;
@@ -17,10 +20,14 @@ import com.google.errorprone.bugpatterns.BugChecker.MethodTreeMatcher;
 import com.google.errorprone.fixes.Fix;
 import com.google.errorprone.fixes.SuggestedFix;
 import com.google.errorprone.matchers.Description;
+import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.AnnotationTree;
 import com.sun.source.tree.MethodTree;
+import com.sun.tools.javac.code.Symbol;
+import com.sun.tools.javac.code.TypeAnnotations.AnnotationType;
+import java.util.Comparator;
 import java.util.List;
-import java.util.Optional;
+import org.jspecify.nullness.Nullable;
 import tech.picnic.errorprone.bugpatterns.util.SourceCode;
 
 /**
@@ -39,6 +46,12 @@ import tech.picnic.errorprone.bugpatterns.util.SourceCode;
 public final class LexicographicalAnnotationListing extends BugChecker
     implements MethodTreeMatcher {
   private static final long serialVersionUID = 1L;
+  private static final Comparator<@Nullable AnnotationType> BY_ANNOTATION_TYPE =
+      (a, b) ->
+          (a == null || a == DECLARATION) && b == TYPE ? -1 : a == TYPE && b == DECLARATION ? 1 : 0;
+
+  /** Instantiates a new {@link LexicographicalAnnotationListing} instance. */
+  public LexicographicalAnnotationListing() {}
 
   @Override
   public Description matchMethod(MethodTree tree, VisitorState state) {
@@ -47,26 +60,29 @@ public final class LexicographicalAnnotationListing extends BugChecker
       return Description.NO_MATCH;
     }
 
-    ImmutableList<? extends AnnotationTree> sortedAnnotations = sort(originalOrdering, state);
+    ImmutableList<? extends AnnotationTree> sortedAnnotations =
+        sort(originalOrdering, ASTHelpers.getSymbol(tree), state);
     if (originalOrdering.equals(sortedAnnotations)) {
       return Description.NO_MATCH;
     }
 
-    Optional<Fix> fix = tryFixOrdering(originalOrdering, sortedAnnotations, state);
-
-    Description.Builder description = buildDescription(originalOrdering.get(0));
-    fix.ifPresent(description::addFix);
-    return description.build();
+    return describeMatch(
+        originalOrdering.get(0), fixOrdering(originalOrdering, sortedAnnotations, state));
   }
 
   private static ImmutableList<? extends AnnotationTree> sort(
-      List<? extends AnnotationTree> annotations, VisitorState state) {
+      List<? extends AnnotationTree> annotations, Symbol symbol, VisitorState state) {
     return annotations.stream()
-        .sorted(comparing(annotation -> SourceCode.treeToString(annotation, state)))
+        .sorted(
+            comparing(
+                    (AnnotationTree annotation) ->
+                        ASTHelpers.getAnnotationType(annotation, symbol, state),
+                    BY_ANNOTATION_TYPE)
+                .thenComparing(annotation -> SourceCode.treeToString(annotation, state)))
         .collect(toImmutableList());
   }
 
-  private static Optional<Fix> tryFixOrdering(
+  private static Fix fixOrdering(
       List<? extends AnnotationTree> originalAnnotations,
       ImmutableList<? extends AnnotationTree> sortedAnnotations,
       VisitorState state) {
@@ -77,6 +93,7 @@ public final class LexicographicalAnnotationListing extends BugChecker
                 SuggestedFix.builder()
                     .replace(original, SourceCode.treeToString(replacement, state)))
         .reduce(SuggestedFix.Builder::merge)
-        .map(SuggestedFix.Builder::build);
+        .map(SuggestedFix.Builder::build)
+        .orElseThrow(() -> new VerifyException("No annotations were provided"));
   }
 }

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

@@ -37,6 +37,8 @@ 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.
@@ -50,6 +52,9 @@ import javax.lang.model.element.Name;
 // `not(some::reference)`.
 // XXX: This check is extremely inefficient due to its reliance on `SuggestedFixes.compilesWithFix`.
 // 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.
 @AutoService(BugChecker.class)
 @BugPattern(
     summary = "Prefer method references over lambda expressions",
@@ -60,6 +65,9 @@ import javax.lang.model.element.Name;
 public final class MethodReferenceUsage extends BugChecker implements LambdaExpressionTreeMatcher {
   private static final long serialVersionUID = 1L;
 
+  /** Instantiates a new {@link MethodReferenceUsage} instance. */
+  public MethodReferenceUsage() {}
+
   @Override
   public Description matchLambdaExpression(LambdaExpressionTree tree, VisitorState state) {
     /*
@@ -122,7 +130,7 @@ public final class MethodReferenceUsage extends BugChecker implements LambdaExpr
           return Optional.empty();
         }
         Symbol sym = ASTHelpers.getSymbol(methodSelect);
-        if (!sym.isStatic()) {
+        if (!ASTHelpers.isStatic(sym)) {
           return constructFix(lambdaExpr, "this", methodSelect);
         }
         return constructFix(lambdaExpr, sym.owner, methodSelect);
@@ -192,7 +200,7 @@ public final class MethodReferenceUsage extends BugChecker implements LambdaExpr
     Name sName = target.getSimpleName();
     Optional<SuggestedFix.Builder> fix = constructFix(lambdaExpr, sName, methodName);
 
-    if (!"java.lang".equals(target.packge().toString())) {
+    if (!"java.lang".equals(ASTHelpers.enclosingPackage(target).toString())) {
       Name fqName = target.getQualifiedName();
       if (!sName.equals(fqName)) {
         return fix.map(b -> b.addImport(fqName.toString()));

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

@@ -40,6 +40,9 @@ public final class MissingRefasterAnnotation extends BugChecker implements Class
               isType("com.google.errorprone.refaster.annotation.BeforeTemplate"),
               isType("com.google.errorprone.refaster.annotation.AfterTemplate")));
 
+  /** Instantiates a new {@link MissingRefasterAnnotation} instance. */
+  public MissingRefasterAnnotation() {}
+
   @Override
   public Description matchClass(ClassTree tree, VisitorState state) {
     long methodTypes =

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

@@ -36,6 +36,9 @@ public final class MockitoStubbing extends BugChecker implements MethodInvocatio
   private static final Matcher<ExpressionTree> MOCKITO_EQ_METHOD =
       staticMethod().onClass("org.mockito.ArgumentMatchers").named("eq");
 
+  /** Instantiates a new {@link MockitoStubbing} instance. */
+  public MockitoStubbing() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     List<? extends ExpressionTree> arguments = tree.getArguments();

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

@@ -4,9 +4,11 @@ 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.MoreTypes.generic;
+import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.raw;
+import static tech.picnic.errorprone.bugpatterns.util.MoreTypes.subOf;
 
 import com.google.auto.service.AutoService;
-import com.google.common.collect.Iterables;
 import com.google.errorprone.BugPattern;
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.bugpatterns.BugChecker;
@@ -16,9 +18,7 @@ import com.google.errorprone.suppliers.Supplier;
 import com.google.errorprone.suppliers.Suppliers;
 import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.MethodInvocationTree;
-import com.sun.source.tree.Tree;
 import com.sun.tools.javac.code.Type;
-import com.sun.tools.javac.util.List;
 import java.util.Optional;
 
 /** A {@link BugChecker} that flags nesting of {@link Optional Optionals}. */
@@ -33,21 +33,16 @@ import java.util.Optional;
 public final class NestedOptionals extends BugChecker implements MethodInvocationTreeMatcher {
   private static final long serialVersionUID = 1L;
   private static final Supplier<Type> OPTIONAL = Suppliers.typeFromClass(Optional.class);
+  private static final Supplier<Type> OPTIONAL_OF_OPTIONAL =
+      VisitorState.memoize(generic(OPTIONAL, subOf(raw(OPTIONAL))));
+
+  /** Instantiates a new {@link NestedOptionals} instance. */
+  public NestedOptionals() {}
 
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
-    return isOptionalOfOptional(tree, state) ? describeMatch(tree) : Description.NO_MATCH;
-  }
-
-  private static boolean isOptionalOfOptional(Tree tree, VisitorState state) {
-    Type optionalType = OPTIONAL.get(state);
-    Type type = ASTHelpers.getType(tree);
-    if (!ASTHelpers.isSubtype(type, optionalType, state)) {
-      return false;
-    }
-
-    List<Type> typeArguments = type.getTypeArguments();
-    return !typeArguments.isEmpty()
-        && ASTHelpers.isSubtype(Iterables.getOnlyElement(typeArguments), optionalType, state);
+    return state.getTypes().isSubtype(ASTHelpers.getType(tree), OPTIONAL_OF_OPTIONAL.get(state))
+        ? describeMatch(tree)
+        : Description.NO_MATCH;
   }
 }

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

@@ -76,6 +76,9 @@ public final class NonEmptyMono extends BugChecker implements MethodInvocationTr
               .onDescendantOf("reactor.core.publisher.Mono")
               .namedAnyOf("defaultIfEmpty", "hasElement", "single"));
 
+  /** Instantiates a new {@link NonEmptyMono} instance. */
+  public NonEmptyMono() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     if (!MONO_SIZE_CHECK.matches(tree, state)) {

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

@@ -70,6 +70,9 @@ public final class PrimitiveComparison extends BugChecker implements MethodInvoc
               .named("thenComparing")
               .withParameters(Function.class.getName()));
 
+  /** Instantiates a new {@link PrimitiveComparison} instance. */
+  public PrimitiveComparison() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     boolean isStatic = STATIC_COMPARISON_METHOD.matches(tree, state);

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

@@ -141,7 +141,7 @@ public final class RedundantStringConversion extends BugChecker
 
   private final Matcher<MethodInvocationTree> conversionMethodMatcher;
 
-  /** Instantiates the default {@link RedundantStringConversion}. */
+  /** Instantiates a default {@link RedundantStringConversion} instance. */
   public RedundantStringConversion() {
     this(ErrorProneFlags.empty());
   }

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

@@ -37,6 +37,9 @@ public final class RefasterAnyOfUsage extends BugChecker implements MethodInvoca
   private static final Matcher<ExpressionTree> REFASTER_ANY_OF =
       staticMethod().onClass(Refaster.class.getName()).named("anyOf");
 
+  /** Instantiates a new {@link RefasterAnyOfUsage} instance. */
+  public RefasterAnyOfUsage() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     if (REFASTER_ANY_OF.matches(tree, state)) {

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

@@ -29,7 +29,7 @@ import java.util.Set;
 import javax.lang.model.element.Modifier;
 
 /**
- * A {@link BugChecker} which suggests a canonical set of modifiers for Refaster class and method
+ * A {@link BugChecker} that suggests a canonical set of modifiers for Refaster class and method
  * definitions.
  */
 @AutoService(BugChecker.class)
@@ -48,6 +48,9 @@ public final class RefasterRuleModifiers extends BugChecker
   private static final Matcher<Tree> REFASTER_METHOD =
       anyOf(BEFORE_TEMPLATE_METHOD, AFTER_TEMPLATE_METHOD, PLACEHOLDER_METHOD);
 
+  /** Instantiates a new {@link RefasterRuleModifiers} instance. */
+  public RefasterRuleModifiers() {}
+
   @Override
   public Description matchClass(ClassTree tree, VisitorState state) {
     if (!hasMatchingMember(tree, BEFORE_TEMPLATE_METHOD, state)) {

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

@@ -83,6 +83,9 @@ public final class RequestMappingAnnotation extends BugChecker implements Method
                   isSameType("org.springframework.web.util.UriBuilder"),
                   isSameType("org.springframework.web.util.UriComponentsBuilder"))));
 
+  /** Instantiates a new {@link RequestMappingAnnotation} instance. */
+  public RequestMappingAnnotation() {}
+
   @Override
   public Description matchMethod(MethodTree tree, VisitorState state) {
     // XXX: Auto-add `@RequestParam` where applicable.

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

@@ -37,6 +37,9 @@ public final class RequestParamType extends BugChecker implements VariableTreeMa
           annotations(AT_LEAST_ONE, isType("org.springframework.web.bind.annotation.RequestParam")),
           anyOf(isSubtypeOf(ImmutableCollection.class), isSubtypeOf(ImmutableMap.class)));
 
+  /** Instantiates a new {@link RequestParamType} instance. */
+  public RequestParamType() {}
+
   @Override
   public Description matchVariable(VariableTree tree, VisitorState state) {
     return HAS_UNSUPPORTED_REQUEST_PARAM.matches(tree, state)

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

@@ -26,6 +26,7 @@ import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.AnnotationTree;
 import com.sun.source.tree.MethodTree;
 import com.sun.source.tree.Tree;
+import tech.picnic.errorprone.bugpatterns.util.ThirdPartyLibrary;
 
 /**
  * A {@link BugChecker} that flags methods with Spring's {@code @Scheduled} annotation that lack New
@@ -46,9 +47,13 @@ public final class ScheduledTransactionTrace extends BugChecker implements Metho
   private static final MultiMatcher<Tree, AnnotationTree> TRACE_ANNOTATION =
       annotations(AT_LEAST_ONE, isType(TRACE_ANNOTATION_FQCN));
 
+  /** Instantiates a new {@link ScheduledTransactionTrace} instance. */
+  public ScheduledTransactionTrace() {}
+
   @Override
   public Description matchMethod(MethodTree tree, VisitorState state) {
-    if (!IS_SCHEDULED.matches(tree, state)) {
+    if (!ThirdPartyLibrary.NEW_RELIC_AGENT_API.isIntroductionAllowed(state)
+        || !IS_SCHEDULED.matches(tree, state)) {
       return Description.NO_MATCH;
     }
 

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

@@ -0,0 +1,350 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.collect.ImmutableList.toImmutableList;
+import static com.google.common.collect.ImmutableMap.toImmutableMap;
+import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
+import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
+import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
+import static java.util.Objects.requireNonNull;
+import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+
+import com.google.auto.service.AutoService;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableSortedSet;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Maps;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.AnnotationTreeMatcher;
+import com.google.errorprone.fixes.Fix;
+import com.google.errorprone.fixes.SuggestedFix;
+import com.google.errorprone.fixes.SuggestedFixes;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.AnnotationTree;
+import com.sun.source.tree.AssignmentTree;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.Tree;
+import com.sun.tools.javac.code.Scope;
+import com.sun.tools.javac.code.Symbol.MethodSymbol;
+import com.sun.tools.javac.code.Symbol.VarSymbol;
+import java.util.Arrays;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Stream;
+import tech.picnic.errorprone.bugpatterns.util.AnnotationAttributeMatcher;
+import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+
+/**
+ * A {@link BugChecker} which flags annotations with time attributes that can be written more
+ * concisely.
+ */
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary = "Simplifies annotations which express an amount of time using a `TimeUnit`",
+    link = BUG_PATTERNS_BASE_URL + "SimplifyTimeAnnotation",
+    linkType = CUSTOM,
+    severity = WARNING,
+    tags = SIMPLIFICATION)
+public final class SimplifyTimeAnnotationCheck extends BugChecker implements AnnotationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final AnnotationAttributeMatcher ARGUMENT_SELECTOR =
+      createAnnotationAttributeMatcher();
+
+  /** Instantiates a new {@link SimplifyTimeAnnotationCheck} instance. */
+  public SimplifyTimeAnnotationCheck() {}
+
+  @Override
+  public Description matchAnnotation(AnnotationTree annotationTree, VisitorState state) {
+    ImmutableList<ExpressionTree> arguments =
+        ARGUMENT_SELECTOR.extractMatchingArguments(annotationTree).collect(toImmutableList());
+
+    if (arguments.isEmpty()) {
+      return Description.NO_MATCH;
+    }
+
+    return trySimplification(annotationTree, arguments, state)
+        .map(fix -> describeMatch(annotationTree, fix))
+        .orElse(Description.NO_MATCH);
+  }
+
+  private static Optional<Fix> trySimplification(
+      AnnotationTree annotation, ImmutableList<ExpressionTree> arguments, VisitorState state) {
+    checkArgument(!arguments.isEmpty());
+
+    AnnotationDescriptor annotationDescriptor =
+        AnnotationDescriptor.from(getAnnotationFqcn(annotation));
+    if (containsAnyAttributeOf(annotation, annotationDescriptor.bannedFields)) {
+      return Optional.empty();
+    }
+
+    ImmutableMap<String, ExpressionTree> indexedAttributes =
+        Maps.uniqueIndex(
+            arguments,
+            expr ->
+                ASTHelpers.getSymbol(((AssignmentTree) expr).getVariable())
+                    .getSimpleName()
+                    .toString());
+
+    TimeUnit currentTimeUnit =
+        getTimeUnit(annotation, annotationDescriptor.timeUnitField, indexedAttributes);
+
+    ImmutableMap<String, Number> timeValues =
+        annotationDescriptor.timeFields.stream()
+            .map(field -> Map.entry(field, getValue(field, indexedAttributes)))
+            .filter(entry -> entry.getValue().isPresent())
+            .collect(toImmutableMap(Map.Entry::getKey, entry -> entry.getValue().orElseThrow()));
+
+    Map<String, TimeSimplifier.Simplification> simplifications =
+        Maps.transformValues(
+            Maps.filterValues(
+                Maps.transformEntries(
+                    timeValues, (field, value) -> trySimplify(value, currentTimeUnit)),
+                Optional::isPresent),
+            Optional::orElseThrow);
+
+    // Some could not be simplified, and since the unit is shared, the others can't either.
+    if (simplifications.size() != timeValues.size()) {
+      return Optional.empty();
+    }
+
+    // The annotation is of the form `@Annotation(v)` or `@Annotation(value = v)`. For the former we
+    // must synthesize the entire annotation, but this is OK for the latter, too.
+    if (indexedAttributes.size() == 1 && simplifications.containsKey("value")) {
+      TimeSimplifier.Simplification simplification = simplifications.get("value");
+      return Optional.of(
+          getImplicitValueAttributeFix(
+              annotation,
+              simplification.value,
+              annotationDescriptor.timeUnitField,
+              simplification.timeUnit,
+              state));
+    }
+
+    // Since each might have a different simplification possible, check the common unit.
+    // Since we only get simplifications iff it's possible, and we check that all can be simplified,
+    // we don't need to check if this equals `currentTimeUnit`.
+    TimeUnit commonUnit =
+        findCommonUnit(
+            ImmutableSet.copyOf(
+                Maps.transformValues(simplifications, simplification -> simplification.timeUnit)
+                    .values()));
+
+    return getExplicitAttributesFix(
+        annotation, simplifications, annotationDescriptor.timeUnitField, commonUnit, state);
+  }
+
+  private static boolean containsAnyAttributeOf(
+      AnnotationTree annotation, ImmutableSet<String> attributes) {
+    return annotation.getArguments().stream()
+        .map(
+            expr ->
+                expr.getKind() == Tree.Kind.ASSIGNMENT
+                    ? ASTHelpers.getSymbol(((AssignmentTree) expr).getVariable())
+                        .getSimpleName()
+                        .toString()
+                    : "value")
+        .anyMatch(attributes::contains);
+  }
+
+  private static Fix getImplicitValueAttributeFix(
+      AnnotationTree annotation,
+      long newValue,
+      String timeUnitField,
+      TimeUnit newTimeUnit,
+      VisitorState state) {
+    String synthesizedAnnotation =
+        SourceCode.treeToString(annotation, state)
+            .replaceFirst(
+                "\\(.+\\)",
+                String.format("(value=%s, %s=%s)", newValue, timeUnitField, newTimeUnit.name()));
+    return SuggestedFix.builder()
+        .replace(annotation, synthesizedAnnotation)
+        .addStaticImport(TimeUnit.class.getName() + '.' + newTimeUnit.name())
+        .build();
+  }
+
+  private static Optional<Fix> getExplicitAttributesFix(
+      AnnotationTree annotation,
+      Map<String, TimeSimplifier.Simplification> simplifications,
+      String timeUnitField,
+      TimeUnit newUnit,
+      VisitorState state) {
+    return simplifications.entrySet().stream()
+        .map(
+            simplificationEntry ->
+                SuggestedFixes.updateAnnotationArgumentValues(
+                        annotation, state, timeUnitField, ImmutableList.of(newUnit.name()))
+                    .merge(
+                        SuggestedFixes.updateAnnotationArgumentValues(
+                            annotation,
+                            state,
+                            simplificationEntry.getKey(),
+                            ImmutableList.of(
+                                String.valueOf(simplificationEntry.getValue().toUnit(newUnit))))))
+        .reduce(SuggestedFix.Builder::merge)
+        .map(builder -> builder.addStaticImport(TimeUnit.class.getName() + '.' + newUnit.name()))
+        .map(SuggestedFix.Builder::build);
+  }
+
+  private static String getAnnotationFqcn(AnnotationTree annotation) {
+    return ASTHelpers.getSymbol(annotation).getQualifiedName().toString();
+  }
+
+  private static Optional<Number> getValue(
+      String field, ImmutableMap<String, ExpressionTree> indexedArguments) {
+    return Optional.ofNullable(indexedArguments.get(field))
+        .filter(AssignmentTree.class::isInstance)
+        .map(AssignmentTree.class::cast)
+        .map(AssignmentTree::getExpression)
+        .map(expr -> ASTHelpers.constValue(expr, Number.class));
+  }
+
+  private static TimeUnit getTimeUnit(
+      AnnotationTree annotation,
+      String field,
+      ImmutableMap<String, ExpressionTree> indexedArguments) {
+    VarSymbol symbol =
+        Optional.ofNullable(indexedArguments.get(field))
+            .map(
+                argumentTree ->
+                    (VarSymbol)
+                        ASTHelpers.getSymbol(((AssignmentTree) argumentTree).getExpression()))
+            .orElseGet(() -> getDefaultTimeUnit(annotation, field));
+    return TimeUnit.valueOf(symbol.getQualifiedName().toString());
+  }
+
+  private static VarSymbol getDefaultTimeUnit(AnnotationTree annotation, String argument) {
+    Scope scope = ASTHelpers.getSymbol(annotation).members();
+    MethodSymbol argumentSymbol =
+        (MethodSymbol)
+            Iterables.getOnlyElement(
+                ASTHelpers.scope(scope)
+                    .getSymbols(symbol -> symbol.getQualifiedName().contentEquals(argument)));
+    return (VarSymbol)
+        requireNonNull(argumentSymbol.getDefaultValue(), "Default value missing").getValue();
+  }
+
+  private static AnnotationAttributeMatcher createAnnotationAttributeMatcher() {
+    ImmutableList<String> toMatch =
+        Arrays.stream(AnnotationDescriptor.values())
+            .flatMap(
+                annotation ->
+                    annotation.timeFields.stream().map(field -> annotation.fqcn + '#' + field))
+            .collect(toImmutableList());
+    return AnnotationAttributeMatcher.create(Optional.of(toMatch), ImmutableList.of());
+  }
+
+  private static Optional<TimeSimplifier.Simplification> trySimplify(Number value, TimeUnit unit) {
+    checkArgument(
+        value instanceof Integer || value instanceof Long,
+        "Only time expressed as an integer or long can be simplified");
+    return TimeSimplifier.simplify(value.longValue(), unit);
+  }
+
+  private static TimeUnit findCommonUnit(ImmutableSet<TimeUnit> units) {
+    return ImmutableSortedSet.copyOf(units).first();
+  }
+
+  private enum AnnotationDescriptor {
+    JUNIT_TIMEOUT("org.junit.jupiter.api.Timeout", ImmutableSet.of("value"), "unit"),
+    SPRING_SCHEDULED(
+        "org.springframework.scheduling.annotation.Scheduled",
+        ImmutableSet.of("fixedDelay", "fixedRate", "initialDelay"),
+        "timeUnit",
+        ImmutableSet.of("fixedDelayString", "fixedRateString", "initialDelayString"));
+
+    /** The fully-qualified class name of the annotation to simplify. */
+    private final String fqcn;
+    /** The attributes containing a value of time. */
+    private final ImmutableSet<String> timeFields;
+    /** The attribute containing the time unit. */
+    private final String timeUnitField;
+    /** The set of attributes that cause the check to back off. */
+    private final ImmutableSet<String> bannedFields;
+
+    AnnotationDescriptor(String fqcn, ImmutableSet<String> timeFields, String timeUnitField) {
+      this(fqcn, timeFields, timeUnitField, ImmutableSet.of());
+    }
+
+    AnnotationDescriptor(
+        String fqcn,
+        ImmutableSet<String> timeFields,
+        String timeUnitField,
+        ImmutableSet<String> bannedFields) {
+      this.fqcn = fqcn;
+      this.timeFields = timeFields;
+      this.timeUnitField = timeUnitField;
+      this.bannedFields = bannedFields;
+    }
+
+    public static AnnotationDescriptor from(String fqcn) {
+      return Arrays.stream(values())
+          .filter(annotation -> annotation.fqcn.equals(fqcn))
+          .findFirst()
+          .orElseThrow(
+              () ->
+                  new IllegalArgumentException(
+                      String.format(
+                          "Unknown enum constant: %s.%s",
+                          AnnotationDescriptor.class.getName(), fqcn)));
+    }
+  }
+
+  /** Utility class to help simplify time expressions. */
+  private static final class TimeSimplifier {
+    private static final ImmutableSortedSet<TimeUnit> TIME_UNITS =
+        ImmutableSortedSet.copyOf(TimeUnit.values());
+
+    /**
+     * Returns a {@link Simplification} (iff possible) that describes how the {@code originalValue}
+     * and {@code originalUnit} can be simplified using a larger {@link TimeUnit}.
+     */
+    static Optional<Simplification> simplify(long originalValue, TimeUnit originalUnit) {
+      return descendingLargerUnits(originalUnit).stream()
+          .flatMap(unit -> trySimplify(originalValue, originalUnit, unit))
+          .findFirst();
+    }
+
+    private static Stream<Simplification> trySimplify(
+        long originalValue, TimeUnit originalUnit, TimeUnit unit) {
+      long converted = unit.convert(originalValue, originalUnit);
+      // Check whether we lose any precision by checking whether we can convert back.
+      return originalValue == originalUnit.convert(converted, unit)
+          ? Stream.of(new Simplification(converted, unit))
+          : Stream.empty();
+    }
+
+    /**
+     * Returns all time units that represent a larger amount of time than {@code unit}, in
+     * descending order.
+     */
+    private static ImmutableSortedSet<TimeUnit> descendingLargerUnits(TimeUnit unit) {
+      return TIME_UNITS.tailSet(unit, /* inclusive= */ false).descendingSet();
+    }
+
+    /** Represents a simplification in terms of the new value and new unit. */
+    private static final class Simplification {
+      private final long value;
+      private final TimeUnit timeUnit;
+
+      Simplification(long value, TimeUnit timeUnit) {
+        this.value = value;
+        this.timeUnit = timeUnit;
+      }
+
+      /**
+       * Converts the value with the unit represented by this simplification to an equivalent value
+       * in the given {@code unit}.
+       */
+      public long toUnit(TimeUnit unit) {
+        return unit.convert(value, timeUnit);
+      }
+    }
+  }
+}

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

@@ -48,6 +48,9 @@ public final class Slf4jLogStatement extends BugChecker implements MethodInvocat
           .onDescendantOf("org.slf4j.Logger")
           .namedAnyOf("trace", "debug", "info", "warn", "error");
 
+  /** Instantiates a new {@link Slf4jLogStatement} instance. */
+  public Slf4jLogStatement() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     if (!SLF4J_LOGGER_INVOCATION.matches(tree, state)) {

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

@@ -57,6 +57,9 @@ public final class SpringMvcAnnotation extends BugChecker implements AnnotationT
           .put("PUT", "PutMapping")
           .build();
 
+  /** Instantiates a new {@link SpringMvcAnnotation} instance. */
+  public SpringMvcAnnotation() {}
+
   @Override
   public Description matchAnnotation(AnnotationTree tree, VisitorState state) {
     // XXX: We could remove the `@RequestMapping` import if not other usages remain.

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

@@ -101,7 +101,8 @@ public final class StaticImport extends BugChecker implements MemberSelectTreeMa
           "org.springframework.http.HttpMethod",
           "org.springframework.http.MediaType",
           "org.testng.Assert",
-          "reactor.function.TupleUtils");
+          "reactor.function.TupleUtils",
+          "tech.picnic.errorprone.bugpatterns.util.MoreTypes");
 
   /** Type members that should be statically imported. */
   @VisibleForTesting
@@ -190,6 +191,9 @@ public final class StaticImport extends BugChecker implements MemberSelectTreeMa
           "of",
           "valueOf");
 
+  /** Instantiates a new {@link StaticImport} instance. */
+  public StaticImport() {}
+
   @Override
   public Description matchMemberSelect(MemberSelectTree tree, VisitorState state) {
     if (!isCandidateContext(state) || !isCandidate(tree)) {

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

@@ -1,9 +1,10 @@
 package tech.picnic.errorprone.bugpatterns;
 
-import static com.google.errorprone.BugPattern.LinkType.NONE;
+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 com.google.auto.service.AutoService;
 import com.google.common.base.Splitter;
@@ -26,12 +27,12 @@ import com.sun.tools.javac.util.Convert;
 import java.util.Formattable;
 import java.util.Iterator;
 import java.util.List;
-import javax.annotation.Nullable;
+import org.jspecify.nullness.Nullable;
 import tech.picnic.errorprone.bugpatterns.util.SourceCode;
 
 /**
- * A {@link BugChecker} which flags {@link String#format(String, Object...)} invocations which can
- * be replaced with a {@link String#join(CharSequence, CharSequence...)} or even a {@link
+ * A {@link BugChecker} that flags {@link String#format(String, Object...)} invocations which can be
+ * replaced with a {@link String#join(CharSequence, CharSequence...)} or even a {@link
  * String#valueOf} invocation.
  */
 // XXX: What about `v1 + "sep" + v2` and similar expressions? Do we want to rewrite those to
@@ -40,7 +41,8 @@ import tech.picnic.errorprone.bugpatterns.util.SourceCode;
 @AutoService(BugChecker.class)
 @BugPattern(
     summary = "Prefer `String#join` over `String#format`",
-    linkType = NONE,
+    link = BUG_PATTERNS_BASE_URL + "StringJoin",
+    linkType = CUSTOM,
     severity = SUGGESTION,
     tags = SIMPLIFICATION)
 public final class StringJoin extends BugChecker implements MethodInvocationTreeMatcher {
@@ -52,6 +54,9 @@ public final class StringJoin extends BugChecker implements MethodInvocationTree
       Suppliers.typeFromClass(CharSequence.class);
   private static final Supplier<Type> FORMATTABLE_TYPE = Suppliers.typeFromClass(Formattable.class);
 
+  /** Instantiates a new {@link StringJoin} instance. */
+  public StringJoin() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     if (!STRING_FORMAT_INVOCATION.matches(tree, state)) {

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

@@ -26,6 +26,9 @@ import java.time.Instant;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
+import java.time.OffsetDateTime;
+import java.time.OffsetTime;
+import java.time.ZonedDateTime;
 
 /** A {@link BugChecker} that flags illegal time-zone related operations. */
 @AutoService(BugChecker.class)
@@ -58,10 +61,16 @@ public final class TimeZoneUsage extends BugChecker implements MethodInvocationT
               .onClassAny(
                   LocalDate.class.getName(),
                   LocalDateTime.class.getName(),
-                  LocalTime.class.getName())
+                  LocalTime.class.getName(),
+                  OffsetDateTime.class.getName(),
+                  OffsetTime.class.getName(),
+                  ZonedDateTime.class.getName())
               .named("now"),
           staticMethod().onClassAny(Instant.class.getName()).named("now").withNoParameters());
 
+  /** Instantiates a new {@link TimeZoneUsage} instance. */
+  public TimeZoneUsage() {}
+
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
     return BANNED_TIME_METHOD.matches(tree, state)

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

@@ -1,4 +1,4 @@
 /** Picnic Error Prone Contrib checks. */
 @com.google.errorprone.annotations.CheckReturnValue
-@javax.annotation.ParametersAreNonnullByDefault
+@org.jspecify.nullness.NullMarked
 package tech.picnic.errorprone.bugpatterns;

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

@@ -21,6 +21,9 @@ public final class MethodMatcherFactory {
   private static final Pattern METHOD_SIGNATURE =
       Pattern.compile("([^\\s#(,)]+)#([^\\s#(,)]+)\\(((?:[^\\s#(,)]+(?:,[^\\s#(,)]+)*)?)\\)");
 
+  /** Instantiates a new {@link MethodMatcherFactory} instance. */
+  public MethodMatcherFactory() {}
+
   /**
    * Creates a {@link Matcher} of methods with any of the given signatures.
    *

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

@@ -0,0 +1,132 @@
+package tech.picnic.errorprone.bugpatterns.util;
+
+import static java.util.stream.Collectors.toCollection;
+
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.suppliers.Supplier;
+import com.google.errorprone.suppliers.Suppliers;
+import com.sun.tools.javac.code.BoundKind;
+import com.sun.tools.javac.code.Type;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.function.BiFunction;
+
+/**
+ * A set of helper methods which together define a DSL for defining {@link Type types}.
+ *
+ * <p>These methods are meant to be statically imported. Example usage:
+ *
+ * <pre>{@code
+ * Supplier<Type> type =
+ *     VisitorState.memoize(
+ *         generic(
+ *             type("reactor.core.publisher.Flux"),
+ *             subOf(generic(type("org.reactivestreams.Publisher"), unbound()))));
+ * }</pre>
+ *
+ * This statement produces a memoized supplier of the type {@code Flux<? extends Publisher<?>>}.
+ */
+public final class MoreTypes {
+  private MoreTypes() {}
+
+  /**
+   * Creates a supplier of the type with the given fully qualified name.
+   *
+   * <p>This method should only be used when building more complex types in combination with other
+   * {@link MoreTypes} methods. In other cases prefer directly calling {@link
+   * Suppliers#typeFromString(String)}.
+   *
+   * @param typeName The type of interest.
+   * @return A supplier which returns the described type if available in the given state, and {@code
+   *     null} otherwise.
+   */
+  public static Supplier<Type> type(String typeName) {
+    return Suppliers.typeFromString(typeName);
+  }
+
+  /**
+   * Creates a supplier of the described generic type.
+   *
+   * @param type The base type of interest.
+   * @param typeArgs The desired type arguments.
+   * @return A supplier which returns the described type if available in the given state, and {@code
+   *     null} otherwise.
+   */
+  // XXX: The given `type` should be a generic type, so perhaps `withParams` would be a better
+  // method name. But the DSL wouldn't look as nice that way.
+  @SafeVarargs
+  @SuppressWarnings("varargs")
+  public static Supplier<Type> generic(Supplier<Type> type, Supplier<Type>... typeArgs) {
+    return propagateNull(
+        type,
+        (state, baseType) -> {
+          List<Type> params =
+              Arrays.stream(typeArgs).map(s -> s.get(state)).collect(toCollection(ArrayList::new));
+          if (params.stream().anyMatch(Objects::isNull)) {
+            return null;
+          }
+
+          return state.getType(baseType, /* isArray= */ false, params);
+        });
+  }
+
+  /**
+   * Creates a raw (erased, non-generic) variant of the given type.
+   *
+   * @param type The base type of interest.
+   * @return A supplier which returns the described type if available in the given state, and {@code
+   *     null} otherwise.
+   */
+  public static Supplier<Type> raw(Supplier<Type> type) {
+    return propagateNull(type, (state, baseType) -> baseType.tsym.erasure(state.getTypes()));
+  }
+
+  /**
+   * Creates a {@code ? super T} wildcard type, with {@code T} bound to the given type.
+   *
+   * @param type The base type of interest.
+   * @return A supplier which returns the described type if available in the given state, and {@code
+   *     null} otherwise.
+   */
+  public static Supplier<Type> superOf(Supplier<Type> type) {
+    return propagateNull(
+        type,
+        (state, baseType) ->
+            new Type.WildcardType(baseType, BoundKind.SUPER, state.getSymtab().boundClass));
+  }
+
+  /**
+   * Creates a {@code ? extends T} wildcard type, with {@code T} bound to the given type.
+   *
+   * @param type The base type of interest.
+   * @return A supplier which returns the described type if available in the given state, and {@code
+   *     null} otherwise.
+   */
+  public static Supplier<Type> subOf(Supplier<Type> type) {
+    return propagateNull(
+        type,
+        (state, baseType) ->
+            new Type.WildcardType(
+                type.get(state), BoundKind.EXTENDS, state.getSymtab().boundClass));
+  }
+
+  /**
+   * Creates an unbound wildcard type ({@code ?}).
+   *
+   * @return A supplier which returns the described type.
+   */
+  public static Supplier<Type> unbound() {
+    return state ->
+        new Type.WildcardType(
+            state.getSymtab().objectType, BoundKind.UNBOUND, state.getSymtab().boundClass);
+  }
+
+  private static Supplier<Type> propagateNull(
+      Supplier<Type> type, BiFunction<VisitorState, Type, Type> transformer) {
+    return state ->
+        Optional.ofNullable(type.get(state)).map(t -> transformer.apply(state, t)).orElse(null);
+  }
+}

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

@@ -0,0 +1,105 @@
+package tech.picnic.errorprone.bugpatterns.util;
+
+import com.google.errorprone.VisitorState;
+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.Symbol.CompletionFailure;
+import com.sun.tools.javac.util.Name;
+
+/**
+ * Utility class that helps decide whether it is appropriate to introduce references to (well-known)
+ * third-party libraries.
+ *
+ * <p>This class should be used by {@link BugChecker}s that may otherwise suggest the introduction
+ * of code that depends on possibly-not-present third-party libraries.
+ */
+// XXX: Consider giving users more fine-grained control. This would be beneficial in cases where a
+// dependency is on the classpath, but new usages are undesirable.
+public enum ThirdPartyLibrary {
+  /**
+   * AssertJ.
+   *
+   * @see <a href="https://assertj.github.io/doc">AssertJ documentation</a>
+   */
+  ASSERTJ("org.assertj.core.api.Assertions"),
+  /**
+   * Google's Guava.
+   *
+   * @see <a href="https://github.com/google/guava">Guava on GitHub</a>
+   */
+  GUAVA("com.google.common.collect.ImmutableList"),
+  /**
+   * New Relic's Java agent API.
+   *
+   * @see <a href="https://github.com/newrelic/newrelic-java-agent/tree/main/newrelic-api">New Relic
+   *     Java agent API on GitHub</a>
+   */
+  NEW_RELIC_AGENT_API("com.newrelic.api.agent.Agent"),
+  /**
+   * VMWare's Project Reactor.
+   *
+   * @see <a href="https://projectreactor.io">Home page</a>
+   */
+  REACTOR("reactor.core.publisher.Flux");
+
+  private static final String IGNORE_CLASSPATH_COMPAT_FLAG =
+      "ErrorProneSupport:IgnoreClasspathCompat";
+
+  @SuppressWarnings("ImmutableEnumChecker" /* Supplier is deterministic. */)
+  private final Supplier<Boolean> canUse;
+
+  /**
+   * Instantiates a {@link ThirdPartyLibrary} enum value.
+   *
+   * @param witnessFqcn The fully-qualified class name of a type that is expected to be on the
+   *     classpath iff the associated third-party library is on the classpath.
+   */
+  ThirdPartyLibrary(String witnessFqcn) {
+    this.canUse = VisitorState.memoize(state -> canIntroduceUsage(witnessFqcn, state));
+  }
+
+  /**
+   * Tells whether it is okay to introduce a dependency on this well-known third party library in
+   * the given context.
+   *
+   * @param state The context under consideration.
+   * @return {@code true} iff it is okay to assume or create a dependency on this library.
+   */
+  public boolean isIntroductionAllowed(VisitorState state) {
+    return canUse.get(state);
+  }
+
+  private static boolean canIntroduceUsage(String className, VisitorState state) {
+    return shouldIgnoreClasspath(state) || isKnownClass(className, state);
+  }
+
+  /**
+   * Attempts to determine whether a class with the given FQCN is on the classpath.
+   *
+   * <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 canLoadClass(String className, VisitorState state) {
+    ClassFinder classFinder = ClassFinder.instance(state.context);
+    Name binaryName = state.binaryNameFromClassname(className);
+    try {
+      classFinder.loadClass(state.getSymtab().unnamedModule, binaryName);
+      return true;
+    } catch (CompletionFailure e) {
+      return false;
+    }
+  }
+
+  private static boolean shouldIgnoreClasspath(VisitorState state) {
+    return state
+        .errorProneOptions()
+        .getFlags()
+        .getBoolean(IGNORE_CLASSPATH_COMPAT_FLAG)
+        .orElse(Boolean.FALSE);
+  }
+}

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

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

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssortedRules.java

@@ -27,7 +27,7 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
 import java.util.stream.Stream;
-import javax.annotation.Nullable;
+import org.jspecify.nullness.Nullable;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 
 /**
@@ -46,11 +46,33 @@ final class AssortedRules {
     }
 
     @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     int after(int index, int size) {
       return checkIndex(index, size);
     }
   }
 
+  /**
+   * Prefer {@link Objects#checkIndex(int, int)} over less descriptive or more verbose alternatives.
+   *
+   * <p>If a custom error message is desired, consider using Guava's {@link
+   * com.google.common.base.Preconditions#checkElementIndex(int, int, String)}.
+   */
+  static final class CheckIndexConditional {
+    @BeforeTemplate
+    void before(int index, int size) {
+      if (index < 0 || index >= size) {
+        throw new IndexOutOfBoundsException();
+      }
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    void after(int index, int size) {
+      checkIndex(index, size);
+    }
+  }
+
   // XXX: We could add a rule for `new EnumMap(Map<K, ? extends V> m)`, but that constructor does
   // not allow an empty non-EnumMap to be provided.
   static final class CreateEnumMap<K extends Enum<K>, V> {
@@ -67,14 +89,12 @@ final class AssortedRules {
 
   static final class MapGetOrNull<K, V, L> {
     @BeforeTemplate
-    @Nullable
-    V before(Map<K, V> map, L key) {
+    @Nullable V before(Map<K, V> map, L key) {
       return map.getOrDefault(key, null);
     }
 
     @AfterTemplate
-    @Nullable
-    V after(Map<K, V> map, L key) {
+    @Nullable V after(Map<K, V> map, L key) {
       return map.get(key);
     }
   }
@@ -112,8 +132,7 @@ final class AssortedRules {
     }
 
     @AfterTemplate
-    @Nullable
-    T after(Iterator<T> iterator, T defaultValue) {
+    @Nullable T after(Iterator<T> iterator, T defaultValue) {
       return Iterators.getNext(iterator, defaultValue);
     }
   }

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/MultimapRules.java

@@ -7,7 +7,7 @@ import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
 import java.util.Collection;
 import java.util.Set;
-import javax.annotation.Nullable;
+import org.jspecify.nullness.Nullable;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 
 /** Refaster rules related to expressions dealing with {@link Multimap}s. */
@@ -50,8 +50,7 @@ final class MultimapRules {
    */
   static final class MultimapGet<K, V> {
     @BeforeTemplate
-    @Nullable
-    Collection<V> before(Multimap<K, V> multimap, K key) {
+    @Nullable Collection<V> before(Multimap<K, V> multimap, K key) {
       return Refaster.anyOf(multimap.asMap(), Multimaps.asMap(multimap)).get(key);
     }
 

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/NullRules.java

@@ -9,7 +9,7 @@ import com.google.errorprone.refaster.annotation.BeforeTemplate;
 import com.google.errorprone.refaster.annotation.UseImportPolicy;
 import java.util.Objects;
 import java.util.function.Predicate;
-import javax.annotation.Nullable;
+import org.jspecify.nullness.Nullable;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 
 /** Refaster rules related to expressions dealing with (possibly) null values. */

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/OptionalRules.java

@@ -16,7 +16,7 @@ import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
 import java.util.stream.Stream;
-import javax.annotation.Nullable;
+import org.jspecify.nullness.Nullable;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 
 /** Refaster rules related to expressions dealing with {@link Optional}s. */
@@ -355,6 +355,42 @@ final class OptionalRules {
     }
   }
 
+  /**
+   * Avoid unnecessary {@link Optional} to {@link Stream} conversion when filtering a value of the
+   * former type.
+   */
+  static final class OptionalFilter<T> {
+    @BeforeTemplate
+    Optional<T> before(Optional<T> optional, Predicate<? super T> predicate) {
+      return Refaster.anyOf(
+          optional.stream().filter(predicate).findFirst(),
+          optional.stream().filter(predicate).findAny());
+    }
+
+    @AfterTemplate
+    Optional<T> after(Optional<T> optional, Predicate<? super T> predicate) {
+      return optional.filter(predicate);
+    }
+  }
+
+  /**
+   * Avoid unnecessary {@link Optional} to {@link Stream} conversion when mapping a value of the
+   * former type.
+   */
+  // XXX: If `StreamMapFirst` also simplifies `.findAny()` expressions, then this rule can be
+  // dropped in favour of `StreamMapFirst` and `OptionalIdentity`.
+  static final class OptionalMap<S, T> {
+    @BeforeTemplate
+    Optional<? extends T> before(Optional<S> optional, Function<? super S, ? extends T> function) {
+      return optional.stream().map(function).findAny();
+    }
+
+    @AfterTemplate
+    Optional<? extends T> after(Optional<S> optional, Function<? super S, ? extends T> function) {
+      return optional.map(function);
+    }
+  }
+
   // XXX: Add a rule for:
   // `optional.flatMap(x -> pred(x) ? Optional.empty() : Optional.of(x))` and variants.
   // (Maybe canonicalize the inner expression. Maybe we rewrite already.)

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/PreconditionsRules.java

@@ -0,0 +1,176 @@
+package tech.picnic.errorprone.refasterrules;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkElementIndex;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkPositionIndex;
+import static com.google.common.base.Preconditions.checkState;
+import static com.google.errorprone.refaster.ImportPolicy.STATIC_IMPORT_ALWAYS;
+
+import com.google.common.base.Preconditions;
+import com.google.errorprone.refaster.annotation.AfterTemplate;
+import com.google.errorprone.refaster.annotation.BeforeTemplate;
+import com.google.errorprone.refaster.annotation.UseImportPolicy;
+import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
+
+/** Refaster templates related to statements dealing with {@link Preconditions}. */
+@OnlineDocumentation
+final class PreconditionsRules {
+  private PreconditionsRules() {}
+
+  /** Prefer {@link Preconditions#checkArgument(boolean)} over more verbose alternatives. */
+  static final class CheckArgument {
+    @BeforeTemplate
+    void before(boolean condition) {
+      if (condition) {
+        throw new IllegalArgumentException();
+      }
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    void after(boolean condition) {
+      checkArgument(!condition);
+    }
+  }
+
+  /** Prefer {@link Preconditions#checkArgument(boolean, Object)} over more verbose alternatives. */
+  static final class CheckArgumentWithMessage {
+    @BeforeTemplate
+    void before(boolean condition, String message) {
+      if (condition) {
+        throw new IllegalArgumentException(message);
+      }
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    void after(boolean condition, String message) {
+      checkArgument(!condition, message);
+    }
+  }
+
+  /**
+   * Prefer {@link Preconditions#checkElementIndex(int, int, String)} over less descriptive or more
+   * verbose alternatives.
+   *
+   * <p>Note that the two-argument {@link Preconditions#checkElementIndex(int, int)} is better
+   * replaced with {@link java.util.Objects#checkIndex(int, int)}.
+   */
+  static final class CheckElementIndexWithMessage {
+    @BeforeTemplate
+    void before(int index, int size, String message) {
+      if (index < 0 || index >= size) {
+        throw new IndexOutOfBoundsException(message);
+      }
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    void after(int index, int size, String message) {
+      checkElementIndex(index, size, message);
+    }
+  }
+
+  /** Prefer {@link Preconditions#checkNotNull(Object)} over more verbose alternatives. */
+  static final class CheckNotNull<T> {
+    @BeforeTemplate
+    void before(T object) {
+      if (object == null) {
+        throw new NullPointerException();
+      }
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    void after(T object) {
+      checkNotNull(object);
+    }
+  }
+
+  /** Prefer {@link Preconditions#checkNotNull(Object, Object)} over more verbose alternatives. */
+  static final class CheckNotNullWithMessage<T> {
+    @BeforeTemplate
+    void before(T object, String message) {
+      if (object == null) {
+        throw new NullPointerException(message);
+      }
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    void after(T object, String message) {
+      checkNotNull(object, message);
+    }
+  }
+
+  /**
+   * Prefer {@link Preconditions#checkPositionIndex(int, int)} over less descriptive or more verbose
+   * alternatives.
+   */
+  static final class CheckPositionIndex {
+    @BeforeTemplate
+    void before(int index, int size) {
+      if (index < 0 || index > size) {
+        throw new IndexOutOfBoundsException();
+      }
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    void after(int index, int size) {
+      checkPositionIndex(index, size);
+    }
+  }
+
+  /**
+   * Prefer {@link Preconditions#checkPositionIndex(int, int, String)} over less descriptive or more
+   * verbose alternatives.
+   */
+  static final class CheckPositionIndexWithMessage {
+    @BeforeTemplate
+    void before(int index, int size, String message) {
+      if (index < 0 || index > size) {
+        throw new IndexOutOfBoundsException(message);
+      }
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    void after(int index, int size, String message) {
+      checkPositionIndex(index, size, message);
+    }
+  }
+
+  /** Prefer {@link Preconditions#checkState(boolean)} over more verbose alternatives. */
+  static final class CheckState {
+    @BeforeTemplate
+    void before(boolean condition) {
+      if (condition) {
+        throw new IllegalStateException();
+      }
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    void after(boolean condition) {
+      checkState(!condition);
+    }
+  }
+
+  /** Prefer {@link Preconditions#checkState(boolean, Object)} over more verbose alternatives. */
+  static final class CheckStateWithMessage {
+    @BeforeTemplate
+    void before(boolean condition, String message) {
+      if (condition) {
+        throw new IllegalStateException(message);
+      }
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    void after(boolean condition, String message) {
+      checkState(!condition, message);
+    }
+  }
+}

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java

@@ -1,10 +1,13 @@
 package tech.picnic.errorprone.refasterrules;
 
 import static com.google.common.collect.MoreCollectors.toOptional;
+import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
 import static com.google.errorprone.refaster.ImportPolicy.STATIC_IMPORT_ALWAYS;
 import static java.util.function.Function.identity;
 import static org.assertj.core.api.Assertions.assertThat;
+import static reactor.function.TupleUtils.function;
 
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.MoreCollectors;
 import com.google.errorprone.refaster.Refaster;
 import com.google.errorprone.refaster.annotation.AfterTemplate;
@@ -14,8 +17,11 @@ import com.google.errorprone.refaster.annotation.NotMatches;
 import com.google.errorprone.refaster.annotation.Placeholder;
 import com.google.errorprone.refaster.annotation.UseImportPolicy;
 import java.time.Duration;
+import java.util.HashMap;
 import java.util.Optional;
 import java.util.concurrent.Callable;
+import java.util.function.BiConsumer;
+import java.util.function.BiFunction;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Predicate;
@@ -25,7 +31,11 @@ import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 import reactor.test.publisher.PublisherProbe;
+import reactor.util.context.Context;
+import reactor.util.function.Tuple2;
+import tech.picnic.errorprone.refaster.annotation.Description;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
+import tech.picnic.errorprone.refaster.annotation.Severity;
 import tech.picnic.errorprone.refaster.matchers.ThrowsCheckedException;
 
 /** Refaster rules related to Reactor expressions and statements. */
@@ -68,6 +78,91 @@ final class ReactorRules {
     }
   }
 
+  /**
+   * Prefer {@link Mono#zip(Mono, Mono)} over a chained {@link Mono#zipWith(Mono)}, as the former
+   * better conveys that the {@link Mono}s may be subscribed to concurrently, and generalizes to
+   * combining three or more reactive streams.
+   */
+  static final class MonoZip<T, S> {
+    @BeforeTemplate
+    Mono<Tuple2<T, S>> before(Mono<T> mono, Mono<S> other) {
+      return mono.zipWith(other);
+    }
+
+    @AfterTemplate
+    Mono<Tuple2<T, S>> after(Mono<T> mono, Mono<S> other) {
+      return Mono.zip(mono, other);
+    }
+  }
+
+  /**
+   * Prefer {@link Mono#zip(Mono, Mono)} with a chained combinator over a chained {@link
+   * Mono#zipWith(Mono, BiFunction)}, as the former better conveys that the {@link Mono}s may be
+   * subscribed to concurrently, and generalizes to combining three or more reactive streams.
+   */
+  static final class MonoZipWithCombinator<T, S, R> {
+    @BeforeTemplate
+    Mono<R> before(Mono<T> mono, Mono<S> other, BiFunction<T, S, R> combinator) {
+      return mono.zipWith(other, combinator);
+    }
+
+    @AfterTemplate
+    Mono<R> after(Mono<T> mono, Mono<S> other, BiFunction<T, S, R> combinator) {
+      return Mono.zip(mono, other).map(function(combinator));
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#zip(Publisher, Publisher)} over a chained {@link Flux#zipWith(Publisher)},
+   * as the former better conveys that the {@link Publisher}s may be subscribed to concurrently, and
+   * generalizes to combining three or more reactive streams.
+   */
+  static final class FluxZip<T, S> {
+    @BeforeTemplate
+    Flux<Tuple2<T, S>> before(Flux<T> flux, Publisher<S> other) {
+      return flux.zipWith(other);
+    }
+
+    @AfterTemplate
+    Flux<Tuple2<T, S>> after(Flux<T> flux, Publisher<S> other) {
+      return Flux.zip(flux, other);
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#zip(Publisher, Publisher)} with a chained combinator over a chained {@link
+   * Flux#zipWith(Publisher, BiFunction)}, as the former better conveys that the {@link Publisher}s
+   * may be subscribed to concurrently, and generalizes to combining three or more reactive streams.
+   */
+  static final class FluxZipWithCombinator<T, S, R> {
+    @BeforeTemplate
+    Flux<R> before(Flux<T> flux, Publisher<S> other, BiFunction<T, S, R> combinator) {
+      return flux.zipWith(other, combinator);
+    }
+
+    @AfterTemplate
+    Flux<R> after(Flux<T> flux, Publisher<S> other, BiFunction<T, S, R> combinator) {
+      return Flux.zip(flux, other).map(function(combinator));
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#zipWithIterable(Iterable)} with a chained combinator over {@link
+   * Flux#zipWithIterable(Iterable, BiFunction)}, as the former generally yields more readable code.
+   */
+  static final class FluxZipWithIterable<T, S, R> {
+    @BeforeTemplate
+    Flux<R> before(Flux<T> flux, Iterable<S> iterable, BiFunction<T, S, R> combinator) {
+      return flux.zipWithIterable(iterable, combinator);
+    }
+
+    @AfterTemplate
+    @UseImportPolicy(STATIC_IMPORT_ALWAYS)
+    Flux<R> after(Flux<T> flux, Iterable<S> iterable, BiFunction<T, S, R> combinator) {
+      return flux.zipWithIterable(iterable).map(function(combinator));
+    }
+  }
+
   /** Don't unnecessarily defer {@link Mono#error(Throwable)}. */
   static final class MonoDeferredError<T> {
     @BeforeTemplate
@@ -141,6 +236,34 @@ final class ReactorRules {
     }
   }
 
+  /**
+   * Prefer {@link Flux#take(long, boolean)} over {@link Flux#take(long)}.
+   *
+   * <p>In Reactor versions prior to 3.5.0, {@code Flux#take(long)} makes an unbounded request
+   * upstream, and is equivalent to {@code Flux#take(long, false)}. In 3.5.0, the behavior of {@code
+   * Flux#take(long)} will change to that of {@code Flux#take(long, true)}.
+   *
+   * <p>The intent with this Refaster rule is to get the new behavior before upgrading to Reactor
+   * 3.5.0.
+   */
+  // XXX: Drop this rule some time after upgrading to Reactor 3.6.0, or introduce a way to apply
+  // this rule only when an older version of Reactor is on the classpath.
+  // XXX: Once Reactor 3.6.0 is out, introduce a rule that rewrites code in the opposite direction.
+  @Description(
+      "Prior to Reactor 3.5.0, `take(n)` requests and unbounded number of elements upstream.")
+  @Severity(WARNING)
+  static final class FluxTake<T> {
+    @BeforeTemplate
+    Flux<T> before(Flux<T> flux, long n) {
+      return flux.take(n);
+    }
+
+    @AfterTemplate
+    Flux<T> after(Flux<T> flux, long n) {
+      return flux.take(n, /* limitRequest= */ true);
+    }
+  }
+
   /** Don't unnecessarily pass an empty publisher to {@link Mono#switchIfEmpty(Mono)}. */
   static final class MonoSwitchIfEmptyOfEmptyPublisher<T> {
     @BeforeTemplate
@@ -240,16 +363,195 @@ final class ReactorRules {
    */
   abstract static class MonoFlatMapToFlux<T, S> {
     @Placeholder(allowsIdentity = true)
-    abstract Mono<S> valueTransformation(@MayOptionallyUse T value);
+    abstract Mono<S> transformation(@MayOptionallyUse T value);
 
     @BeforeTemplate
     Flux<S> before(Mono<T> mono) {
-      return mono.flatMapMany(v -> valueTransformation(v));
+      return mono.flatMapMany(v -> transformation(v));
     }
 
     @AfterTemplate
     Flux<S> after(Mono<T> mono) {
-      return mono.flatMap(v -> valueTransformation(v)).flux();
+      return mono.flatMap(v -> transformation(v)).flux();
+    }
+  }
+
+  /**
+   * Prefer {@link Mono#map(Function)} over alternatives that unnecessarily require an inner
+   * subscription.
+   */
+  abstract static class MonoMap<T, S> {
+    @Placeholder(allowsIdentity = true)
+    abstract S transformation(@MayOptionallyUse T value);
+
+    @BeforeTemplate
+    Mono<S> before(Mono<T> mono) {
+      return mono.flatMap(x -> Mono.just(transformation(x)));
+    }
+
+    @AfterTemplate
+    Mono<S> after(Mono<T> mono) {
+      return mono.map(x -> transformation(x));
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#map(Function)} over alternatives that unnecessarily require an inner
+   * subscription.
+   */
+  abstract static class FluxMap<T, S> {
+    @Placeholder(allowsIdentity = true)
+    abstract S transformation(@MayOptionallyUse T value);
+
+    @BeforeTemplate
+    Flux<S> before(Flux<T> flux, boolean delayUntilEnd, int maxConcurrency, int prefetch) {
+      return Refaster.anyOf(
+          flux.concatMap(x -> Mono.just(transformation(x))),
+          flux.concatMap(x -> Flux.just(transformation(x))),
+          flux.concatMap(x -> Mono.just(transformation(x)), prefetch),
+          flux.concatMap(x -> Flux.just(transformation(x)), prefetch),
+          flux.concatMapDelayError(x -> Mono.just(transformation(x))),
+          flux.concatMapDelayError(x -> Flux.just(transformation(x))),
+          flux.concatMapDelayError(x -> Mono.just(transformation(x)), prefetch),
+          flux.concatMapDelayError(x -> Flux.just(transformation(x)), prefetch),
+          flux.concatMapDelayError(x -> Mono.just(transformation(x)), delayUntilEnd, prefetch),
+          flux.concatMapDelayError(x -> Flux.just(transformation(x)), delayUntilEnd, prefetch),
+          flux.flatMap(x -> Mono.just(transformation(x)), maxConcurrency),
+          flux.flatMap(x -> Flux.just(transformation(x)), maxConcurrency),
+          flux.flatMap(x -> Mono.just(transformation(x)), maxConcurrency, prefetch),
+          flux.flatMap(x -> Flux.just(transformation(x)), maxConcurrency, prefetch),
+          flux.flatMapDelayError(x -> Mono.just(transformation(x)), maxConcurrency, prefetch),
+          flux.flatMapDelayError(x -> Flux.just(transformation(x)), maxConcurrency, prefetch),
+          flux.flatMapSequential(x -> Mono.just(transformation(x)), maxConcurrency),
+          flux.flatMapSequential(x -> Flux.just(transformation(x)), maxConcurrency),
+          flux.flatMapSequential(x -> Mono.just(transformation(x)), maxConcurrency, prefetch),
+          flux.flatMapSequential(x -> Flux.just(transformation(x)), maxConcurrency, prefetch),
+          flux.flatMapSequentialDelayError(
+              x -> Mono.just(transformation(x)), maxConcurrency, prefetch),
+          flux.flatMapSequentialDelayError(
+              x -> Flux.just(transformation(x)), maxConcurrency, prefetch),
+          flux.switchMap(x -> Mono.just(transformation(x))),
+          flux.switchMap(x -> Flux.just(transformation(x))));
+    }
+
+    @AfterTemplate
+    Flux<S> after(Flux<T> flux) {
+      return flux.map(x -> transformation(x));
+    }
+  }
+
+  /**
+   * Prefer {@link Mono#mapNotNull(Function)} over alternatives that unnecessarily require an inner
+   * subscription.
+   */
+  abstract static class MonoMapNotNull<T, S> {
+    @Placeholder(allowsIdentity = true)
+    abstract S transformation(@MayOptionallyUse T value);
+
+    @BeforeTemplate
+    Mono<S> before(Mono<T> mono) {
+      return mono.flatMap(
+          x ->
+              Refaster.anyOf(
+                  Mono.justOrEmpty(transformation(x)), Mono.fromSupplier(() -> transformation(x))));
+    }
+
+    @AfterTemplate
+    Mono<S> after(Mono<T> mono) {
+      return mono.mapNotNull(x -> transformation(x));
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#mapNotNull(Function)} over alternatives that unnecessarily require an inner
+   * subscription.
+   */
+  abstract static class FluxMapNotNull<T, S> {
+    @Placeholder(allowsIdentity = true)
+    abstract S transformation(@MayOptionallyUse T value);
+
+    @BeforeTemplate
+    Publisher<S> before(Flux<T> flux, boolean delayUntilEnd, int maxConcurrency, int prefetch) {
+      return Refaster.anyOf(
+          flux.concatMap(
+              x ->
+                  Refaster.anyOf(
+                      Mono.justOrEmpty(transformation(x)),
+                      Mono.fromSupplier(() -> transformation(x)))),
+          flux.concatMap(
+              x ->
+                  Refaster.anyOf(
+                      Mono.justOrEmpty(transformation(x)),
+                      Mono.fromSupplier(() -> transformation(x))),
+              prefetch),
+          flux.concatMapDelayError(
+              x ->
+                  Refaster.anyOf(
+                      Mono.justOrEmpty(transformation(x)),
+                      Mono.fromSupplier(() -> transformation(x)))),
+          flux.concatMapDelayError(
+              x ->
+                  Refaster.anyOf(
+                      Mono.justOrEmpty(transformation(x)),
+                      Mono.fromSupplier(() -> transformation(x))),
+              prefetch),
+          flux.concatMapDelayError(
+              x ->
+                  Refaster.anyOf(
+                      Mono.justOrEmpty(transformation(x)),
+                      Mono.fromSupplier(() -> transformation(x))),
+              delayUntilEnd,
+              prefetch),
+          flux.flatMap(
+              x ->
+                  Refaster.anyOf(
+                      Mono.justOrEmpty(transformation(x)),
+                      Mono.fromSupplier(() -> transformation(x))),
+              maxConcurrency),
+          flux.flatMap(
+              x ->
+                  Refaster.anyOf(
+                      Mono.justOrEmpty(transformation(x)),
+                      Mono.fromSupplier(() -> transformation(x))),
+              maxConcurrency,
+              prefetch),
+          flux.flatMapDelayError(
+              x ->
+                  Refaster.anyOf(
+                      Mono.justOrEmpty(transformation(x)),
+                      Mono.fromSupplier(() -> transformation(x))),
+              maxConcurrency,
+              prefetch),
+          flux.flatMapSequential(
+              x ->
+                  Refaster.anyOf(
+                      Mono.justOrEmpty(transformation(x)),
+                      Mono.fromSupplier(() -> transformation(x))),
+              maxConcurrency),
+          flux.flatMapSequential(
+              x ->
+                  Refaster.anyOf(
+                      Mono.justOrEmpty(transformation(x)),
+                      Mono.fromSupplier(() -> transformation(x))),
+              maxConcurrency,
+              prefetch),
+          flux.flatMapSequentialDelayError(
+              x ->
+                  Refaster.anyOf(
+                      Mono.justOrEmpty(transformation(x)),
+                      Mono.fromSupplier(() -> transformation(x))),
+              maxConcurrency,
+              prefetch),
+          flux.switchMap(
+              x ->
+                  Refaster.anyOf(
+                      Mono.justOrEmpty(transformation(x)),
+                      Mono.fromSupplier(() -> transformation(x)))));
+    }
+
+    @AfterTemplate
+    Flux<S> after(Flux<T> flux) {
+      return flux.mapNotNull(x -> transformation(x));
     }
   }
 
@@ -349,6 +651,42 @@ final class ReactorRules {
     }
   }
 
+  /**
+   * Prefer {@link Mono#doOnError(Class, Consumer)} over {@link Mono#doOnError(Predicate, Consumer)}
+   * where possible.
+   */
+  static final class MonoDoOnError<T> {
+    @BeforeTemplate
+    Mono<T> before(
+        Mono<T> mono, Class<? extends Throwable> clazz, Consumer<? super Throwable> onError) {
+      return mono.doOnError(clazz::isInstance, onError);
+    }
+
+    @AfterTemplate
+    Mono<T> after(
+        Mono<T> mono, Class<? extends Throwable> clazz, Consumer<? super Throwable> onError) {
+      return mono.doOnError(clazz, onError);
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#doOnError(Class, Consumer)} over {@link Flux#doOnError(Predicate, Consumer)}
+   * where possible.
+   */
+  static final class FluxDoOnError<T> {
+    @BeforeTemplate
+    Flux<T> before(
+        Flux<T> flux, Class<? extends Throwable> clazz, Consumer<? super Throwable> onError) {
+      return flux.doOnError(clazz::isInstance, onError);
+    }
+
+    @AfterTemplate
+    Flux<T> after(
+        Flux<T> flux, Class<? extends Throwable> clazz, Consumer<? super Throwable> onError) {
+      return flux.doOnError(clazz, onError);
+    }
+  }
+
   /** Prefer {@link Mono#onErrorComplete()} over more contrived alternatives. */
   static final class MonoOnErrorComplete<T> {
     @BeforeTemplate
@@ -375,6 +713,240 @@ final class ReactorRules {
     }
   }
 
+  /** Prefer {@link Mono#onErrorComplete(Class)}} over more contrived alternatives. */
+  static final class MonoOnErrorCompleteClass<T> {
+    @BeforeTemplate
+    Mono<T> before(Mono<T> mono, Class<? extends Throwable> clazz) {
+      return Refaster.anyOf(
+          mono.onErrorComplete(clazz::isInstance), mono.onErrorResume(clazz, e -> Mono.empty()));
+    }
+
+    @AfterTemplate
+    Mono<T> after(Mono<T> mono, Class<? extends Throwable> clazz) {
+      return mono.onErrorComplete(clazz);
+    }
+  }
+
+  /** Prefer {@link Flux#onErrorComplete(Class)}} over more contrived alternatives. */
+  static final class FluxOnErrorCompleteClass<T> {
+    @BeforeTemplate
+    Flux<T> before(Flux<T> flux, Class<? extends Throwable> clazz) {
+      return Refaster.anyOf(
+          flux.onErrorComplete(clazz::isInstance),
+          flux.onErrorResume(clazz, e -> Refaster.anyOf(Mono.empty(), Flux.empty())));
+    }
+
+    @AfterTemplate
+    Flux<T> after(Flux<T> flux, Class<? extends Throwable> clazz) {
+      return flux.onErrorComplete(clazz);
+    }
+  }
+
+  /** Prefer {@link Mono#onErrorComplete(Predicate)}} over more contrived alternatives. */
+  static final class MonoOnErrorCompletePredicate<T> {
+    @BeforeTemplate
+    Mono<T> before(Mono<T> mono, Predicate<? super Throwable> predicate) {
+      return mono.onErrorResume(predicate, e -> Mono.empty());
+    }
+
+    @AfterTemplate
+    Mono<T> after(Mono<T> mono, Predicate<? super Throwable> predicate) {
+      return mono.onErrorComplete(predicate);
+    }
+  }
+
+  /** Prefer {@link Flux#onErrorComplete(Predicate)}} over more contrived alternatives. */
+  static final class FluxOnErrorCompletePredicate<T> {
+    @BeforeTemplate
+    Flux<T> before(Flux<T> flux, Predicate<? super Throwable> predicate) {
+      return flux.onErrorResume(predicate, e -> Refaster.anyOf(Mono.empty(), Flux.empty()));
+    }
+
+    @AfterTemplate
+    Flux<T> after(Flux<T> flux, Predicate<? super Throwable> predicate) {
+      return flux.onErrorComplete(predicate);
+    }
+  }
+
+  /**
+   * Prefer {@link Mono#onErrorContinue(Class, BiConsumer)} over {@link
+   * Mono#onErrorContinue(Predicate, BiConsumer)} where possible.
+   */
+  static final class MonoOnErrorContinue<T> {
+    @BeforeTemplate
+    Mono<T> before(
+        Mono<T> mono,
+        Class<? extends Throwable> clazz,
+        BiConsumer<Throwable, Object> errorConsumer) {
+      return mono.onErrorContinue(clazz::isInstance, errorConsumer);
+    }
+
+    @AfterTemplate
+    Mono<T> after(
+        Mono<T> mono,
+        Class<? extends Throwable> clazz,
+        BiConsumer<Throwable, Object> errorConsumer) {
+      return mono.onErrorContinue(clazz, errorConsumer);
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#onErrorContinue(Class, BiConsumer)} over {@link
+   * Flux#onErrorContinue(Predicate, BiConsumer)} where possible.
+   */
+  static final class FluxOnErrorContinue<T> {
+    @BeforeTemplate
+    Flux<T> before(
+        Flux<T> flux,
+        Class<? extends Throwable> clazz,
+        BiConsumer<Throwable, Object> errorConsumer) {
+      return flux.onErrorContinue(clazz::isInstance, errorConsumer);
+    }
+
+    @AfterTemplate
+    Flux<T> after(
+        Flux<T> flux,
+        Class<? extends Throwable> clazz,
+        BiConsumer<Throwable, Object> errorConsumer) {
+      return flux.onErrorContinue(clazz, errorConsumer);
+    }
+  }
+
+  /**
+   * Prefer {@link Mono#onErrorMap(Class, Function)} over {@link Mono#onErrorMap(Predicate,
+   * Function)} where possible.
+   */
+  static final class MonoOnErrorMap<T> {
+    @BeforeTemplate
+    Mono<T> before(
+        Mono<T> mono,
+        Class<? extends Throwable> clazz,
+        Function<? super Throwable, ? extends Throwable> mapper) {
+      return mono.onErrorMap(clazz::isInstance, mapper);
+    }
+
+    @AfterTemplate
+    Mono<T> after(
+        Mono<T> mono,
+        Class<? extends Throwable> clazz,
+        Function<? super Throwable, ? extends Throwable> mapper) {
+      return mono.onErrorMap(clazz, mapper);
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#onErrorMap(Class, Function)} over {@link Flux#onErrorMap(Predicate,
+   * Function)} where possible.
+   */
+  static final class FluxOnErrorMap<T> {
+    @BeforeTemplate
+    Flux<T> before(
+        Flux<T> flux,
+        Class<? extends Throwable> clazz,
+        Function<? super Throwable, ? extends Throwable> mapper) {
+      return flux.onErrorMap(clazz::isInstance, mapper);
+    }
+
+    @AfterTemplate
+    Flux<T> after(
+        Flux<T> flux,
+        Class<? extends Throwable> clazz,
+        Function<? super Throwable, ? extends Throwable> mapper) {
+      return flux.onErrorMap(clazz, mapper);
+    }
+  }
+
+  /**
+   * Prefer {@link Mono#onErrorResume(Class, Function)} over {@link Mono#onErrorResume(Predicate,
+   * Function)} where possible.
+   */
+  static final class MonoOnErrorResume<T> {
+    @BeforeTemplate
+    Mono<T> before(
+        Mono<T> mono,
+        Class<? extends Throwable> clazz,
+        Function<? super Throwable, ? extends Mono<? extends T>> fallback) {
+      return mono.onErrorResume(clazz::isInstance, fallback);
+    }
+
+    @AfterTemplate
+    Mono<T> after(
+        Mono<T> mono,
+        Class<? extends Throwable> clazz,
+        Function<? super Throwable, ? extends Mono<? extends T>> fallback) {
+      return mono.onErrorResume(clazz, fallback);
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#onErrorResume(Class, Function)} over {@link Flux#onErrorResume(Predicate,
+   * Function)} where possible.
+   */
+  static final class FluxOnErrorResume<T> {
+    @BeforeTemplate
+    Flux<T> before(
+        Flux<T> flux,
+        Class<? extends Throwable> clazz,
+        Function<? super Throwable, ? extends Publisher<? extends T>> fallback) {
+      return flux.onErrorResume(clazz::isInstance, fallback);
+    }
+
+    @AfterTemplate
+    Flux<T> after(
+        Flux<T> flux,
+        Class<? extends Throwable> clazz,
+        Function<? super Throwable, ? extends Publisher<? extends T>> fallback) {
+      return flux.onErrorResume(clazz, fallback);
+    }
+  }
+
+  /**
+   * Prefer {@link Mono#onErrorReturn(Class, Object)} over {@link Mono#onErrorReturn(Predicate,
+   * Object)} where possible.
+   */
+  static final class MonoOnErrorReturn<T> {
+    @BeforeTemplate
+    Mono<T> before(Mono<T> mono, Class<? extends Throwable> clazz, T fallbackValue) {
+      return mono.onErrorReturn(clazz::isInstance, fallbackValue);
+    }
+
+    @AfterTemplate
+    Mono<T> after(Mono<T> mono, Class<? extends Throwable> clazz, T fallbackValue) {
+      return mono.onErrorReturn(clazz, fallbackValue);
+    }
+  }
+
+  /**
+   * Prefer {@link Flux#onErrorReturn(Class, Object)} over {@link Flux#onErrorReturn(Predicate,
+   * Object)} where possible.
+   */
+  static final class FluxOnErrorReturn<T> {
+    @BeforeTemplate
+    Flux<T> before(Flux<T> flux, Class<? extends Throwable> clazz, T fallbackValue) {
+      return flux.onErrorReturn(clazz::isInstance, fallbackValue);
+    }
+
+    @AfterTemplate
+    Flux<T> after(Flux<T> flux, Class<? extends Throwable> clazz, T fallbackValue) {
+      return flux.onErrorReturn(clazz, fallbackValue);
+    }
+  }
+
+  /** Prefer {@link reactor.util.context.Context#empty()}} over more verbose alternatives. */
+  // XXX: Consider introducing an `IsEmpty` matcher that identifies a wide range of guaranteed-empty
+  // `Collection` and `Map` expressions.
+  static final class ContextEmpty {
+    @BeforeTemplate
+    Context before() {
+      return Context.of(Refaster.anyOf(new HashMap<>(), ImmutableMap.of()));
+    }
+
+    @AfterTemplate
+    Context after() {
+      return Context.empty();
+    }
+  }
+
   /** Prefer {@link PublisherProbe#empty()}} over more verbose alternatives. */
   static final class PublisherProbeEmpty<T> {
     @BeforeTemplate

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/StreamRules.java

@@ -168,8 +168,9 @@ final class StreamRules {
    * Where possible, clarify that a mapping operation will be applied only to a single stream
    * element.
    */
-  // XXX: Consider whether to have a similar rule for `.findAny()`. For parallel streams it
-  // wouldn't be quite the same....
+  // XXX: Implement a similar rule for `.findAny()`. For parallel streams this wouldn't be quite the
+  // same, so such a rule requires a `Matcher` that heuristically identifies `Stream` expressions
+  // with deterministic order.
   // XXX: This change is not equivalent for `null`-returning functions, as the original code throws
   // an NPE if the first element is `null`, while the latter yields an empty `Optional`.
   static final class StreamMapFirst<T, S> {

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/StringRules.java

@@ -16,7 +16,7 @@ import java.util.Collection;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.function.Function;
-import javax.annotation.Nullable;
+import org.jspecify.nullness.Nullable;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 
 /** Refaster rules related to expressions dealing with {@link String}s. */

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/TimeRules.java

@@ -13,9 +13,11 @@ import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
 import java.time.OffsetDateTime;
+import java.time.OffsetTime;
 import java.time.Period;
 import java.time.ZoneId;
 import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
 import java.time.chrono.ChronoLocalDate;
 import java.time.chrono.ChronoLocalDateTime;
 import java.time.chrono.ChronoZonedDateTime;
@@ -64,7 +66,83 @@ final class TimeRules {
     }
   }
 
-  /** Prefer {@link Instant#atOffset(ZoneOffset)} over the more verbose alternative. */
+  /** Prefer {@link LocalDate#ofInstant(Instant, ZoneId)} over more indirect alternatives. */
+  static final class LocalDateOfInstant {
+    @BeforeTemplate
+    LocalDate before(Instant instant, ZoneId zoneId) {
+      return Refaster.anyOf(
+          instant.atZone(zoneId).toLocalDate(),
+          LocalDateTime.ofInstant(instant, zoneId).toLocalDate(),
+          OffsetDateTime.ofInstant(instant, zoneId).toLocalDate());
+    }
+
+    @BeforeTemplate
+    LocalDate before(Instant instant, ZoneOffset zoneId) {
+      return instant.atOffset(zoneId).toLocalDate();
+    }
+
+    @AfterTemplate
+    LocalDate after(Instant instant, ZoneId zoneId) {
+      return LocalDate.ofInstant(instant, zoneId);
+    }
+  }
+
+  /** Prefer {@link LocalDateTime#ofInstant(Instant, ZoneId)} over more indirect alternatives. */
+  static final class LocalDateTimeOfInstant {
+    @BeforeTemplate
+    LocalDateTime before(Instant instant, ZoneId zoneId) {
+      return Refaster.anyOf(
+          instant.atZone(zoneId).toLocalDateTime(),
+          OffsetDateTime.ofInstant(instant, zoneId).toLocalDateTime());
+    }
+
+    @BeforeTemplate
+    LocalDateTime before(Instant instant, ZoneOffset zoneId) {
+      return instant.atOffset(zoneId).toLocalDateTime();
+    }
+
+    @AfterTemplate
+    LocalDateTime after(Instant instant, ZoneId zoneId) {
+      return LocalDateTime.ofInstant(instant, zoneId);
+    }
+  }
+
+  /** Prefer {@link LocalTime#ofInstant(Instant, ZoneId)} over more indirect alternatives. */
+  static final class LocalTimeOfInstant {
+    @BeforeTemplate
+    LocalTime before(Instant instant, ZoneId zoneId) {
+      return Refaster.anyOf(
+          instant.atZone(zoneId).toLocalTime(),
+          LocalDateTime.ofInstant(instant, zoneId).toLocalTime(),
+          OffsetDateTime.ofInstant(instant, zoneId).toLocalTime(),
+          OffsetTime.ofInstant(instant, zoneId).toLocalTime());
+    }
+
+    @BeforeTemplate
+    LocalTime before(Instant instant, ZoneOffset zoneId) {
+      return instant.atOffset(zoneId).toLocalTime();
+    }
+
+    @AfterTemplate
+    LocalTime after(Instant instant, ZoneId zoneId) {
+      return LocalTime.ofInstant(instant, zoneId);
+    }
+  }
+
+  /** Prefer {@link OffsetDateTime#ofInstant(Instant, ZoneId)} over more indirect alternatives. */
+  static final class OffsetDateTimeOfInstant {
+    @BeforeTemplate
+    OffsetDateTime before(Instant instant, ZoneId zoneId) {
+      return instant.atZone(zoneId).toOffsetDateTime();
+    }
+
+    @AfterTemplate
+    OffsetDateTime after(Instant instant, ZoneId zoneId) {
+      return OffsetDateTime.ofInstant(instant, zoneId);
+    }
+  }
+
+  /** Prefer {@link Instant#atOffset(ZoneOffset)} over more verbose alternatives. */
   static final class InstantAtOffset {
     @BeforeTemplate
     OffsetDateTime before(Instant instant, ZoneOffset zoneOffset) {
@@ -77,6 +155,37 @@ final class TimeRules {
     }
   }
 
+  /** Prefer {@link OffsetTime#ofInstant(Instant, ZoneId)} over more indirect alternatives. */
+  static final class OffsetTimeOfInstant {
+    @BeforeTemplate
+    OffsetTime before(Instant instant, ZoneId zoneId) {
+      return OffsetDateTime.ofInstant(instant, zoneId).toOffsetTime();
+    }
+
+    @BeforeTemplate
+    OffsetTime before(Instant instant, ZoneOffset zoneId) {
+      return instant.atOffset(zoneId).toOffsetTime();
+    }
+
+    @AfterTemplate
+    OffsetTime after(Instant instant, ZoneId zoneId) {
+      return OffsetTime.ofInstant(instant, zoneId);
+    }
+  }
+
+  /** Prefer {@link Instant#atZone(ZoneId)} over more verbose alternatives. */
+  static final class InstantAtZone {
+    @BeforeTemplate
+    ZonedDateTime before(Instant instant, ZoneId zoneId) {
+      return ZonedDateTime.ofInstant(instant, zoneId);
+    }
+
+    @AfterTemplate
+    ZonedDateTime after(Instant instant, ZoneId zoneId) {
+      return instant.atZone(zoneId);
+    }
+  }
+
   /** Use {@link Clock#systemUTC()} when possible. */
   static final class UtcClock {
     @BeforeTemplate

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

@@ -1,4 +1,4 @@
 /** Picnic Refaster rules. */
 @com.google.errorprone.annotations.CheckReturnValue
-@javax.annotation.ParametersAreNonnullByDefault
+@org.jspecify.nullness.NullMarked
 package tech.picnic.errorprone.refasterrules;

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

@@ -65,6 +65,23 @@ final class CollectorMutabilityTest {
         .doTest();
   }
 
+  @Test
+  void identificationWithoutGuavaOnClasspath() {
+    compilationTestHelper
+        .withClasspath()
+        .addSourceLines(
+            "A.java",
+            "import java.util.stream.Collectors;",
+            "import java.util.stream.Stream;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Stream.empty().collect(Collectors.toList());",
+            "  }",
+            "}")
+        .doTest();
+  }
+
   @Test
   void replacementFirstSuggestedFix() {
     refactoringTestHelper

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

@@ -4,6 +4,7 @@ import static com.google.errorprone.BugCheckerRefactoringTestHelper.newInstance;
 
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
 import com.google.errorprone.BugCheckerRefactoringTestHelper.FixChoosers;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
 import com.google.errorprone.CompilationTestHelper;
 import org.junit.jupiter.api.Test;
 
@@ -33,6 +34,14 @@ final class FluxFlatMapUsageTest {
             "    Flux.just(1).flatMapSequential(Flux::just);",
             "    // BUG: Diagnostic contains:",
             "    Flux.just(1).<String>flatMapSequential(i -> Flux.just(String.valueOf(i)));",
+            "    // BUG: Diagnostic contains:",
+            "    Flux.just(1, 2).groupBy(i -> i).flatMap(Flux::just);",
+            "    // BUG: Diagnostic contains:",
+            "    Flux.just(1, 2).groupBy(i -> i).<String>flatMap(i -> Flux.just(String.valueOf(i)));",
+            "    // BUG: Diagnostic contains:",
+            "    Flux.just(1, 2).groupBy(i -> i).flatMapSequential(Flux::just);",
+            "    // BUG: Diagnostic contains:",
+            "    Flux.just(1, 2).groupBy(i -> i).<String>flatMapSequential(i -> Flux.just(String.valueOf(i)));",
             "",
             "    Mono.just(1).flatMap(Mono::just);",
             "    Flux.just(1).concatMap(Flux::just);",
@@ -71,9 +80,13 @@ final class FluxFlatMapUsageTest {
             "import reactor.core.publisher.Flux;",
             "",
             "class A {",
+            "  private static final int MAX_CONCURRENCY = 8;",
+            "",
             "  void m() {",
             "    Flux.just(1).flatMap(Flux::just);",
             "    Flux.just(1).flatMapSequential(Flux::just);",
+            "    Flux.just(1, 2).groupBy(i -> i).flatMap(Flux::just);",
+            "    Flux.just(1, 2).groupBy(i -> i).flatMapSequential(Flux::just);",
             "  }",
             "}")
         .addOutputLines(
@@ -81,12 +94,16 @@ final class FluxFlatMapUsageTest {
             "import reactor.core.publisher.Flux;",
             "",
             "class A {",
+            "  private static final int MAX_CONCURRENCY = 8;",
+            "",
             "  void m() {",
             "    Flux.just(1).concatMap(Flux::just);",
             "    Flux.just(1).concatMap(Flux::just);",
+            "    Flux.just(1, 2).groupBy(i -> i).flatMap(Flux::just, MAX_CONCURRENCY);",
+            "    Flux.just(1, 2).groupBy(i -> i).flatMapSequential(Flux::just, MAX_CONCURRENCY);",
             "  }",
             "}")
-        .doTest();
+        .doTest(TestMode.TEXT_MATCH);
   }
 
   @Test
@@ -103,6 +120,8 @@ final class FluxFlatMapUsageTest {
             "  void m() {",
             "    Flux.just(1).flatMap(Flux::just);",
             "    Flux.just(1).flatMapSequential(Flux::just);",
+            "    Flux.just(1, 2).groupBy(i -> i).flatMap(Flux::just);",
+            "    Flux.just(1, 2).groupBy(i -> i).flatMapSequential(Flux::just);",
             "  }",
             "}")
         .addOutputLines(
@@ -115,8 +134,10 @@ final class FluxFlatMapUsageTest {
             "  void m() {",
             "    Flux.just(1).flatMap(Flux::just, MAX_CONCURRENCY);",
             "    Flux.just(1).flatMapSequential(Flux::just, MAX_CONCURRENCY);",
+            "    Flux.just(1, 2).groupBy(i -> i).concatMap(Flux::just);",
+            "    Flux.just(1, 2).groupBy(i -> i).concatMap(Flux::just);",
             "  }",
             "}")
-        .doTest();
+        .doTest(TestMode.TEXT_MATCH);
   }
 }

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

@@ -0,0 +1,54 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+
+final class IsInstanceLambdaUsageTest {
+  private final CompilationTestHelper compilationTestHelper =
+      CompilationTestHelper.newInstance(IsInstanceLambdaUsage.class, getClass());
+  private final BugCheckerRefactoringTestHelper refactoringTestHelper =
+      BugCheckerRefactoringTestHelper.newInstance(IsInstanceLambdaUsage.class, getClass());
+
+  @Test
+  void identification() {
+    compilationTestHelper
+        .addSourceLines(
+            "A.java",
+            "import java.util.stream.Stream;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    // BUG: Diagnostic contains:",
+            "    Stream.of(1).filter(i -> i instanceof Integer);",
+            "    Stream.of(2).filter(Integer.class::isInstance);",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    refactoringTestHelper
+        .addInputLines(
+            "A.java",
+            "import java.util.stream.Stream;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Stream.of(1).filter(i -> i instanceof Integer);",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import java.util.stream.Stream;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Stream.of(1).filter(Integer.class::isInstance);",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}

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

@@ -1,7 +1,5 @@
 package tech.picnic.errorprone.bugpatterns;
 
-import static com.google.common.base.Predicates.containsPattern;
-
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
 import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
 import com.google.errorprone.CompilationTestHelper;
@@ -9,9 +7,7 @@ import org.junit.jupiter.api.Test;
 
 final class LexicographicalAnnotationListingTest {
   private final CompilationTestHelper compilationTestHelper =
-      CompilationTestHelper.newInstance(LexicographicalAnnotationListing.class, getClass())
-          .expectErrorMessage(
-              "X", containsPattern("Sort annotations lexicographically where possible"));
+      CompilationTestHelper.newInstance(LexicographicalAnnotationListing.class, getClass());
   private final BugCheckerRefactoringTestHelper refactoringTestHelper =
       BugCheckerRefactoringTestHelper.newInstance(
           LexicographicalAnnotationListing.class, getClass());
@@ -21,7 +17,9 @@ final class LexicographicalAnnotationListingTest {
     compilationTestHelper
         .addSourceLines(
             "A.java",
+            "import java.lang.annotation.ElementType;",
             "import java.lang.annotation.Repeatable;",
+            "import java.lang.annotation.Target;",
             "",
             "interface A {",
             "  @Repeatable(Foos.class)",
@@ -33,6 +31,7 @@ final class LexicographicalAnnotationListingTest {
             "    Bar[] anns() default {};",
             "  }",
             "",
+            "  @Target(ElementType.METHOD)",
             "  @interface Bar {",
             "    String[] value() default {};",
             "  }",
@@ -45,11 +44,21 @@ final class LexicographicalAnnotationListingTest {
             "    Foo[] value();",
             "  }",
             "",
-            "  // BUG: Diagnostic matches: X",
+            "  @Target(ElementType.TYPE_USE)",
+            "  @interface FooTypeUse {",
+            "    String[] value() default {};",
+            "  }",
+            "",
+            "  @Target(ElementType.TYPE_USE)",
+            "  @interface BarTypeUse {",
+            "    String[] value() default {};",
+            "  }",
+            "",
+            "  // BUG: Diagnostic contains:",
             "  @Foo",
             "  @Bar",
             "  A unsortedSimpleCase();",
-            "  // BUG: Diagnostic matches: X",
+            "  // BUG: Diagnostic contains:",
             "  @Foo()",
             "  @Bar()",
             "  A unsortedWithParens();",
@@ -61,12 +70,12 @@ final class LexicographicalAnnotationListingTest {
             "  @Foo()",
             "  A sortedAnnotationsOneWithParens();",
             "",
-            "  // BUG: Diagnostic matches: X",
+            "  // BUG: Diagnostic contains:",
             "  @Foo",
             "  @Baz",
             "  @Bar",
             "  A threeUnsortedAnnotationsSameInitialLetter();",
-            "  // BUG: Diagnostic matches: X",
+            "  // BUG: Diagnostic contains:",
             "  @Bar",
             "  @Foo()",
             "  @Baz",
@@ -77,16 +86,16 @@ final class LexicographicalAnnotationListingTest {
             "  @Foo()",
             "  A threeSortedAnnotations();",
             "",
-            "  // BUG: Diagnostic matches: X",
+            "  // BUG: Diagnostic contains:",
             "  @Foo({\"b\"})",
             "  @Bar({\"a\"})",
             "  A unsortedWithStringAttributes();",
-            "  // BUG: Diagnostic matches: X",
+            "  // BUG: Diagnostic contains:",
             "  @Baz(str = {\"a\", \"b\"})",
             "  @Foo(ints = {1, 0})",
             "  @Bar",
             "  A unsortedWithAttributes();",
-            "  // BUG: Diagnostic matches: X",
+            "  // BUG: Diagnostic contains:",
             "  @Bar",
             "  @Foo(anns = {@Bar(\"b\"), @Bar(\"a\")})",
             "  @Baz",
@@ -101,11 +110,23 @@ final class LexicographicalAnnotationListingTest {
             "  @Foo(ints = {1, 2})",
             "  @Foo({\"b\"})",
             "  A sortedRepeatableAnnotation();",
-            "  // BUG: Diagnostic matches: X",
+            "  // BUG: Diagnostic contains:",
             "  @Foo(anns = {@Bar(\"b\"), @Bar(\"a\")})",
             "  @Bar",
             "  @Foo(ints = {1, 2})",
             "  A unsortedRepeatableAnnotation();",
+            "",
+            "  // BUG: Diagnostic contains:",
+            "  default @FooTypeUse @BarTypeUse A unsortedTypeAnnotations() {",
+            "    return null;",
+            "  }",
+            "",
+            "  // BUG: Diagnostic contains:",
+            "  @Baz",
+            "  @Bar",
+            "  default @FooTypeUse @BarTypeUse A unsortedTypeUseAndOtherAnnotations() {",
+            "    return null;",
+            "  }",
             "}")
         .doTest();
   }
@@ -115,7 +136,9 @@ final class LexicographicalAnnotationListingTest {
     refactoringTestHelper
         .addInputLines(
             "A.java",
+            "import java.lang.annotation.ElementType;",
             "import java.lang.annotation.Repeatable;",
+            "import java.lang.annotation.Target;",
             "",
             "interface A {",
             "  @Repeatable(Foos.class)",
@@ -127,6 +150,7 @@ final class LexicographicalAnnotationListingTest {
             "    Bar[] anns() default {};",
             "  }",
             "",
+            "  @Target(ElementType.METHOD)",
             "  @interface Bar {",
             "    String[] value() default {};",
             "  }",
@@ -139,6 +163,16 @@ final class LexicographicalAnnotationListingTest {
             "    Foo[] value();",
             "  }",
             "",
+            "  @Target(ElementType.TYPE_USE)",
+            "  @interface FooTypeUse {",
+            "    String[] value() default {};",
+            "  }",
+            "",
+            "  @Target(ElementType.TYPE_USE)",
+            "  @interface BarTypeUse {",
+            "    String[] value() default {};",
+            "  }",
+            "",
             "  @Bar",
             "  A singleAnnotation();",
             "",
@@ -174,10 +208,18 @@ final class LexicographicalAnnotationListingTest {
             "  @Bar",
             "  @Foo(ints = {1, 2})",
             "  A unsortedRepeatableAnnotation();",
+            "",
+            "  @Baz",
+            "  @Bar",
+            "  default @FooTypeUse @BarTypeUse A unsortedWithTypeUseAnnotations() {",
+            "    return null;",
+            "  }",
             "}")
         .addOutputLines(
             "A.java",
+            "import java.lang.annotation.ElementType;",
             "import java.lang.annotation.Repeatable;",
+            "import java.lang.annotation.Target;",
             "",
             "interface A {",
             "  @Repeatable(Foos.class)",
@@ -189,6 +231,7 @@ final class LexicographicalAnnotationListingTest {
             "    Bar[] anns() default {};",
             "  }",
             "",
+            "  @Target(ElementType.METHOD)",
             "  @interface Bar {",
             "    String[] value() default {};",
             "  }",
@@ -201,6 +244,16 @@ final class LexicographicalAnnotationListingTest {
             "    Foo[] value();",
             "  }",
             "",
+            "  @Target(ElementType.TYPE_USE)",
+            "  @interface FooTypeUse {",
+            "    String[] value() default {};",
+            "  }",
+            "",
+            "  @Target(ElementType.TYPE_USE)",
+            "  @interface BarTypeUse {",
+            "    String[] value() default {};",
+            "  }",
+            "",
             "  @Bar",
             "  A singleAnnotation();",
             "",
@@ -236,6 +289,12 @@ final class LexicographicalAnnotationListingTest {
             "  @Foo(anns = {@Bar(\"b\"), @Bar(\"a\")})",
             "  @Foo(ints = {1, 2})",
             "  A unsortedRepeatableAnnotation();",
+            "",
+            "  @Bar",
+            "  @Baz",
+            "  default @BarTypeUse @FooTypeUse A unsortedWithTypeUseAnnotations() {",
+            "    return null;",
+            "  }",
             "}")
         .doTest(TestMode.TEXT_MATCH);
   }

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

@@ -19,7 +19,7 @@ final class RequestParamTypeTest {
             "import java.util.List;",
             "import java.util.Map;",
             "import java.util.Set;",
-            "import javax.annotation.Nullable;",
+            "import org.jspecify.nullness.Nullable;",
             "import org.springframework.web.bind.annotation.DeleteMapping;",
             "import org.springframework.web.bind.annotation.GetMapping;",
             "import org.springframework.web.bind.annotation.PostMapping;",

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

@@ -4,6 +4,7 @@ import com.google.errorprone.BugCheckerRefactoringTestHelper;
 import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
 import com.google.errorprone.CompilationTestHelper;
 import org.junit.jupiter.api.Test;
+import org.springframework.scheduling.annotation.Scheduled;
 
 final class ScheduledTransactionTraceTest {
   private final CompilationTestHelper compilationTestHelper =
@@ -43,6 +44,21 @@ final class ScheduledTransactionTraceTest {
         .doTest();
   }
 
+  @Test
+  void identificationWithoutNewRelicAgentApiOnClasspath() {
+    compilationTestHelper
+        .withClasspath(Scheduled.class)
+        .addSourceLines(
+            "A.java",
+            "import org.springframework.scheduling.annotation.Scheduled;",
+            "",
+            "class A {",
+            "  @Scheduled(fixedDelay = 1)",
+            "  void scheduledButNotTraced() {}",
+            "}")
+        .doTest();
+  }
+
   @Test
   void replacement() {
     refactoringTestHelper

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

@@ -0,0 +1,146 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+
+public final class SimplifyTimeAnnotationCheckTest {
+  private final CompilationTestHelper compilationTestHelper =
+      CompilationTestHelper.newInstance(SimplifyTimeAnnotationCheck.class, getClass());
+  private final BugCheckerRefactoringTestHelper refactoringTestHelper =
+      BugCheckerRefactoringTestHelper.newInstance(SimplifyTimeAnnotationCheck.class, getClass());
+
+  @Test
+  void identification() {
+    compilationTestHelper
+        .addSourceLines(
+            "A.java",
+            "import java.util.concurrent.TimeUnit;",
+            "import org.junit.jupiter.api.Timeout;",
+            "",
+            "interface A {",
+            "  @Timeout(6)",
+            "  A noSimplification();",
+            "  // BUG: Diagnostic contains:",
+            "  @Timeout(60)",
+            "  A simple();",
+            "  // BUG: Diagnostic contains:",
+            "  @Timeout(value = 60 * 1000, unit = TimeUnit.MILLISECONDS)",
+            "  A explicitUnit();",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void identificationBannedField() {
+    compilationTestHelper
+        .addSourceLines(
+            "A.java",
+            "import org.springframework.scheduling.annotation.Scheduled;",
+            "",
+            "interface A {",
+            "  // BUG: Diagnostic contains:",
+            "  @Scheduled(fixedDelay = 6_000)",
+            "  A scheduledFixedDelay();",
+            "",
+            "  @Scheduled(fixedDelay = 6_000, fixedRateString = \"\")",
+            "  A bannedAttribute();",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    refactoringTestHelper
+        .addInputLines(
+            "in/A.java",
+            "import org.junit.jupiter.api.Timeout;",
+            "import org.springframework.scheduling.annotation.Scheduled;",
+            "",
+            "interface A {",
+            "  @Timeout(value = 60)",
+            "  A simple();",
+            "",
+            "  @Scheduled(fixedDelay = 6_000)",
+            "  A scheduledFixedDelay();",
+            "",
+            "  @Scheduled(fixedDelay = 5_000, initialDelay = 6_000, fixedRate = 7_000)",
+            "  A scheduledMultiple();",
+            "",
+            "  @Scheduled(fixedDelay = 60_000, initialDelay = 6_000, fixedRate = 7_000)",
+            "  A scheduledCommonUnit();",
+            "",
+            "  @Scheduled(fixedDelay = 5, initialDelay = 6_000, fixedRate = 7_000)",
+            "  A scheduledNoSimplification();",
+            "}")
+        .addOutputLines(
+            "out/A.java",
+            "import static java.util.concurrent.TimeUnit.MINUTES;",
+            "import static java.util.concurrent.TimeUnit.SECONDS;",
+            "",
+            "import org.junit.jupiter.api.Timeout;",
+            "import org.springframework.scheduling.annotation.Scheduled;",
+            "",
+            "interface A {",
+            "  @Timeout(value = 1, unit = MINUTES)",
+            "  A simple();",
+            "",
+            "  @Scheduled(timeUnit = SECONDS, fixedDelay = 6)",
+            "  A scheduledFixedDelay();",
+            "",
+            "  @Scheduled(timeUnit = SECONDS, fixedDelay = 5, initialDelay = 6, fixedRate = 7)",
+            "  A scheduledMultiple();",
+            "",
+            "  @Scheduled(timeUnit = SECONDS, fixedDelay = 60, initialDelay = 6, fixedRate = 7)",
+            "  A scheduledCommonUnit();",
+            "",
+            "  @Scheduled(fixedDelay = 5, initialDelay = 6_000, fixedRate = 7_000)",
+            "  A scheduledNoSimplification();",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacementValueOnly() {
+    refactoringTestHelper
+        .addInputLines(
+            "in/A.java",
+            "import org.junit.jupiter.api.Timeout;",
+            "",
+            "interface A {",
+            "  @Timeout(60)",
+            "  A simple();",
+            "}")
+        .addOutputLines(
+            "out/A.java",
+            "import static java.util.concurrent.TimeUnit.MINUTES;",
+            "",
+            "import org.junit.jupiter.api.Timeout;",
+            "",
+            "interface A {",
+            "  @Timeout(value = 1, unit = MINUTES)",
+            "  A simple();",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacementFqcn() {
+    refactoringTestHelper
+        .addInputLines(
+            "in/A.java",
+            "interface A {",
+            "  @org.junit.jupiter.api.Timeout(60)",
+            "  A simple();",
+            "}")
+        .addOutputLines(
+            "out/A.java",
+            "import static java.util.concurrent.TimeUnit.MINUTES;",
+            "",
+            "interface A {",
+            "  @org.junit.jupiter.api.Timeout(value = 1, unit = MINUTES)",
+            "  A simple();",
+            "}")
+        .doTest();
+  }
+}

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

@@ -19,7 +19,6 @@ final class SpringMvcAnnotationTest {
             "import static org.springframework.web.bind.annotation.RequestMethod.DELETE;",
             "import static org.springframework.web.bind.annotation.RequestMethod.GET;",
             "import static org.springframework.web.bind.annotation.RequestMethod.HEAD;",
-            "import static org.springframework.web.bind.annotation.RequestMethod.PATCH;",
             "import static org.springframework.web.bind.annotation.RequestMethod.POST;",
             "import static org.springframework.web.bind.annotation.RequestMethod.PUT;",
             "",
@@ -50,7 +49,7 @@ final class SpringMvcAnnotationTest {
             "  @RequestMapping(method = {DELETE})",
             "  A delete();",
             "  // BUG: Diagnostic contains:",
-            "  @RequestMapping(method = {PATCH})",
+            "  @RequestMapping(method = {org.springframework.web.bind.annotation.RequestMethod.PATCH})",
             "  A patch();",
             "",
             "  @RequestMapping(method = HEAD)",

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

@@ -1,17 +1,11 @@
 package tech.picnic.errorprone.bugpatterns;
 
-import static com.google.common.base.Predicates.containsPattern;
-
 import com.google.errorprone.CompilationTestHelper;
 import org.junit.jupiter.api.Test;
 
 final class TimeZoneUsageTest {
   private final CompilationTestHelper compilationHelper =
-      CompilationTestHelper.newInstance(TimeZoneUsage.class, getClass())
-          .expectErrorMessage(
-              "X",
-              containsPattern(
-                  "Derive the current time from an existing `Clock` Spring bean, and don't rely on a `Clock`'s time zone"));
+      CompilationTestHelper.newInstance(TimeZoneUsage.class, getClass());
 
   @Test
   void identification() {
@@ -26,7 +20,10 @@ final class TimeZoneUsageTest {
             "import java.time.LocalDate;",
             "import java.time.LocalDateTime;",
             "import java.time.LocalTime;",
+            "import java.time.OffsetDateTime;",
+            "import java.time.OffsetTime;",
             "import java.time.ZoneId;",
+            "import java.time.ZonedDateTime;",
             "",
             "class A {",
             "  void m() {",
@@ -36,48 +33,69 @@ final class TimeZoneUsageTest {
             "    Clock.offset(clock, Duration.ZERO);",
             "    Clock.tick(clock, Duration.ZERO);",
             "",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    Clock.systemUTC();",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    Clock.systemDefaultZone();",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    Clock.system(UTC);",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    Clock.tickMillis(UTC);",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    Clock.tickMinutes(UTC);",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    Clock.tickSeconds(UTC);",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    clock.getZone();",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    clock.withZone(UTC);",
             "",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    Instant.now();",
             "    // This is equivalent to `clock.instant()`, which is fine.",
             "    Instant.now(clock);",
             "",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    LocalDate.now();",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    LocalDate.now(clock);",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    LocalDate.now(UTC);",
             "",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    LocalDateTime.now();",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    LocalDateTime.now(clock);",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    LocalDateTime.now(UTC);",
             "",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    LocalTime.now();",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    LocalTime.now(clock);",
-            "    // BUG: Diagnostic matches: X",
+            "    // BUG: Diagnostic contains:",
             "    LocalTime.now(UTC);",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    OffsetDateTime.now();",
+            "    // BUG: Diagnostic contains:",
+            "    OffsetDateTime.now(clock);",
+            "    // BUG: Diagnostic contains:",
+            "    OffsetDateTime.now(UTC);",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    OffsetTime.now();",
+            "    // BUG: Diagnostic contains:",
+            "    OffsetTime.now(clock);",
+            "    // BUG: Diagnostic contains:",
+            "    OffsetTime.now(UTC);",
+            "",
+            "    // BUG: Diagnostic contains:",
+            "    ZonedDateTime.now();",
+            "    // BUG: Diagnostic contains:",
+            "    ZonedDateTime.now(clock);",
+            "    // BUG: Diagnostic contains:",
+            "    ZonedDateTime.now(UTC);",
             "  }",
             "",
             "  abstract class ForwardingClock extends Clock {",

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

@@ -0,0 +1,188 @@
+package tech.picnic.errorprone.bugpatterns.util;
+
+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 com.google.common.collect.ImmutableSet;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.CompilationTestHelper;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.suppliers.Supplier;
+import com.google.errorprone.util.ASTHelpers;
+import com.google.errorprone.util.Signatures;
+import com.sun.source.tree.MethodInvocationTree;
+import com.sun.tools.javac.code.Type;
+import java.util.ArrayList;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+final class MoreTypesTest {
+  private static final ImmutableSet<Supplier<Type>> TYPES =
+      ImmutableSet.of(
+          // Invalid types.
+          type("java.lang.Nonexistent"),
+          generic(type("java.util.Integer"), unbound()),
+          // Valid types.
+          type("java.lang.String"),
+          type("java.lang.Number"),
+          superOf(type("java.lang.Number")),
+          subOf(type("java.lang.Number")),
+          type("java.lang.Integer"),
+          superOf(type("java.lang.Integer")),
+          subOf(type("java.lang.Integer")),
+          type("java.util.Optional"),
+          raw(type("java.util.Optional")),
+          generic(type("java.util.Optional"), unbound()),
+          generic(type("java.util.Optional"), type("java.lang.Number")),
+          type("java.util.Collection"),
+          raw(type("java.util.Collection")),
+          generic(type("java.util.Collection"), unbound()),
+          generic(type("java.util.Collection"), type("java.lang.Number")),
+          generic(type("java.util.Collection"), superOf(type("java.lang.Number"))),
+          generic(type("java.util.Collection"), subOf(type("java.lang.Number"))),
+          generic(type("java.util.Collection"), type("java.lang.Integer")),
+          generic(type("java.util.Collection"), superOf(type("java.lang.Integer"))),
+          generic(type("java.util.Collection"), subOf(type("java.lang.Integer"))),
+          type("java.util.List"),
+          raw(type("java.util.List")),
+          generic(type("java.util.List"), unbound()),
+          generic(type("java.util.List"), type("java.lang.Number")),
+          generic(type("java.util.List"), superOf(type("java.lang.Number"))),
+          generic(type("java.util.List"), subOf(type("java.lang.Number"))),
+          generic(type("java.util.List"), type("java.lang.Integer")),
+          generic(type("java.util.List"), superOf(type("java.lang.Integer"))),
+          generic(type("java.util.List"), subOf(type("java.lang.Integer"))),
+          generic(
+              type("java.util.Map"),
+              type("java.lang.String"),
+              subOf(generic(type("java.util.Collection"), superOf(type("java.lang.Short"))))));
+
+  @Test
+  void matcher() {
+    CompilationTestHelper.newInstance(SubtypeFlagger.class, getClass())
+        .addSourceLines(
+            "/A.java",
+            "import java.util.Collection;",
+            "import java.util.List;",
+            "import java.util.Map;",
+            "import java.util.Optional;",
+            "import java.util.Set;",
+            "",
+            "class A<S, T> {",
+            "  void m() {",
+            "    Object object = factory();",
+            "    A a = factory();",
+            "",
+            "    // BUG: Diagnostic contains: [Number, ? super Number, Integer, ? super Integer]",
+            "    int integer = factory();",
+            "",
+            "    // BUG: Diagnostic contains: [String]",
+            "    String string = factory();",
+            "",
+            "    // BUG: Diagnostic contains: [Optional]",
+            "    Optional rawOptional = factory();",
+            "    // BUG: Diagnostic contains: [Optional, Optional<?>]",
+            "    Optional<S> optionalOfS = factory();",
+            "    // BUG: Diagnostic contains: [Optional, Optional<?>]",
+            "    Optional<T> optionalOfT = factory();",
+            "    // BUG: Diagnostic contains: [Optional, Optional<?>, Optional<Number>]",
+            "    Optional<Number> optionalOfNumber = factory();",
+            "    // BUG: Diagnostic contains: [Optional, Optional<?>]",
+            "    Optional<Integer> optionalOfInteger = factory();",
+            "",
+            "    // BUG: Diagnostic contains: [Collection]",
+            "    Collection rawCollection = factory();",
+            "    // BUG: Diagnostic contains: [Collection, Collection<?>, Collection<Number>, Collection<? super",
+            "    // Number>, Collection<? extends Number>, Collection<? super Integer>]",
+            "    Collection<Number> collectionOfNumber = factory();",
+            "    // BUG: Diagnostic contains: [Collection, Collection<?>, Collection<? extends Number>,",
+            "    // Collection<Integer>, Collection<? super Integer>, Collection<? extends Integer>]",
+            "    Collection<Integer> collectionOfInteger = factory();",
+            "    // BUG: Diagnostic contains: [Collection, Collection<?>, Collection<? extends Number>]",
+            "    Collection<Short> collectionOfShort = factory();",
+            "",
+            "    // BUG: Diagnostic contains: [Collection, List]",
+            "    List rawList = factory();",
+            "    // BUG: Diagnostic contains: [Collection, Collection<?>, Collection<Number>, Collection<? super",
+            "    // Number>, Collection<? extends Number>, Collection<? super Integer>, List, List<?>,",
+            "    // List<Number>, List<? super Number>, List<? extends Number>, List<? super Integer>]",
+            "    List<Number> listOfNumber = factory();",
+            "    // BUG: Diagnostic contains: [Collection, Collection<?>, Collection<? extends Number>,",
+            "    // Collection<Integer>, Collection<? super Integer>, Collection<? extends Integer>, List,",
+            "    // List<?>, List<? extends Number>, List<Integer>, List<? super Integer>, List<? extends",
+            "    // Integer>]",
+            "    List<Integer> listOfInteger = factory();",
+            "    // BUG: Diagnostic contains: [Collection, Collection<?>, Collection<? extends Number>, List,",
+            "    // List<?>, List<? extends Number>]",
+            "    List<Short> listOfShort = factory();",
+            "",
+            "    // BUG: Diagnostic contains: [Collection]",
+            "    Set rawSet = factory();",
+            "    // BUG: Diagnostic contains: [Collection, Collection<?>, Collection<Number>, Collection<? super",
+            "    // Number>, Collection<? extends Number>, Collection<? super Integer>]",
+            "    Set<Number> setOfNumber = factory();",
+            "    // BUG: Diagnostic contains: [Collection, Collection<?>, Collection<? extends Number>,",
+            "    // Collection<Integer>, Collection<? super Integer>, Collection<? extends Integer>]",
+            "    Set<Integer> setOfInteger = factory();",
+            "    // BUG: Diagnostic contains: [Collection, Collection<?>, Collection<? extends Number>]",
+            "    Set<Short> setOfShort = factory();",
+            "",
+            "    Map rawMap = factory();",
+            "    Map<Number, Collection<Number>> mapFromNumberToCollectionOfNumber = factory();",
+            "    Map<Number, Collection<Short>> mapFromNumberToCollectionOfShort = factory();",
+            "    Map<Number, Collection<Integer>> mapFromNumberToCollectionOfInteger = factory();",
+            "    // BUG: Diagnostic contains: [Map<String, ? extends Collection<? super Short>>]",
+            "    Map<String, Collection<Number>> mapFromStringToCollectionOfNumber = factory();",
+            "    // BUG: Diagnostic contains: [Map<String, ? extends Collection<? super Short>>]",
+            "    Map<String, Collection<Short>> mapFromStringToCollectionOfShort = factory();",
+            "    Map<String, Collection<Integer>> mapFromStringToCollectionOfInteger = factory();",
+            "    // BUG: Diagnostic contains: [Map<String, ? extends Collection<? super Short>>]",
+            "    Map<String, List<Number>> mapFromStringToListOfNumber = factory();",
+            "    // BUG: Diagnostic contains: [Map<String, ? extends Collection<? super Short>>]",
+            "    Map<String, List<Short>> mapFromStringToListOfShort = factory();",
+            "    Map<String, List<Integer>> mapFromStringToListOfInteger = factory();",
+            "  }",
+            "",
+            "  private <T> T factory() {",
+            "    return null;",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  /**
+   * A {@link BugChecker} that flags method invocations that are a subtype of any type contained in
+   * {@link #TYPES}.
+   */
+  @BugPattern(summary = "Flags invocations of methods with select return types", severity = ERROR)
+  public static final class SubtypeFlagger extends BugChecker
+      implements MethodInvocationTreeMatcher {
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+      Type treeType = ASTHelpers.getType(tree);
+
+      List<String> matches = new ArrayList<>();
+
+      for (Supplier<Type> type : TYPES) {
+        Type testType = type.get(state);
+        if (testType != null && state.getTypes().isSubtype(treeType, testType)) {
+          matches.add(Signatures.prettyType(testType));
+        }
+      }
+
+      return matches.isEmpty()
+          ? Description.NO_MATCH
+          : buildDescription(tree).setMessage(matches.toString()).build();
+    }
+  }
+}

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

@@ -0,0 +1,115 @@
+package tech.picnic.errorprone.bugpatterns.util;
+
+import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
+import static java.util.stream.Collectors.joining;
+
+import com.google.common.collect.ImmutableList;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.CompilationTestHelper;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.ClassTreeMatcher;
+import com.google.errorprone.matchers.Description;
+import com.sun.source.tree.ClassTree;
+import java.util.Arrays;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import reactor.core.publisher.Flux;
+
+final class ThirdPartyLibraryTest {
+  private final CompilationTestHelper compilationTestHelper =
+      CompilationTestHelper.newInstance(TestChecker.class, getClass());
+
+  @Test
+  void isIntroductionAllowed() {
+    compilationTestHelper
+        .addSourceLines(
+            "A.java",
+            "// BUG: Diagnostic contains: ASSERTJ: true, GUAVA: true, NEW_RELIC_AGENT_API: true, REACTOR: true",
+            "class A {}")
+        .doTest();
+  }
+
+  @Test
+  void isIntroductionAllowedWitnessClassesInSymtab() {
+    compilationTestHelper
+        .addSourceLines(
+            "A.java",
+            "import com.google.common.collect.ImmutableList;",
+            "import com.newrelic.api.agent.Agent;",
+            "import org.assertj.core.api.Assertions;",
+            "import reactor.core.publisher.Flux;",
+            "",
+            "// BUG: Diagnostic contains: ASSERTJ: true, GUAVA: true, NEW_RELIC_AGENT_API: true, REACTOR: true",
+            "class A {",
+            "  void m(Class<?> clazz) {",
+            "    m(Assertions.class);",
+            "    m(ImmutableList.class);",
+            "    m(Agent.class);",
+            "    m(Flux.class);",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void isIntroductionAllowedWitnessClassesPartiallyOnClassPath() {
+    compilationTestHelper
+        .withClasspath(ImmutableList.class, Flux.class)
+        .addSourceLines(
+            "A.java",
+            "// BUG: Diagnostic contains: ASSERTJ: false, GUAVA: true, NEW_RELIC_AGENT_API: false, REACTOR: true",
+            "class A {}")
+        .doTest();
+  }
+
+  @Test
+  void isIntroductionAllowedWitnessClassesNotOnClassPath() {
+    compilationTestHelper
+        .withClasspath()
+        .addSourceLines(
+            "A.java",
+            "// BUG: Diagnostic contains: ASSERTJ: false, GUAVA: false, NEW_RELIC_AGENT_API: false, REACTOR:",
+            "// false",
+            "class A {}")
+        .doTest();
+  }
+
+  @ParameterizedTest
+  @ValueSource(booleans = {true, false})
+  void isIntroductionAllowedIgnoreClasspathCompat(boolean ignoreClassPath) {
+    compilationTestHelper
+        .setArgs("-XepOpt:ErrorProneSupport:IgnoreClasspathCompat=" + ignoreClassPath)
+        .withClasspath(ImmutableList.class, Flux.class)
+        .addSourceLines(
+            "A.java",
+            String.format(
+                "// BUG: Diagnostic contains: ASSERTJ: %s, GUAVA: true, NEW_RELIC_AGENT_API: %s, REACTOR: true",
+                ignoreClassPath, ignoreClassPath),
+            "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 {
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    public Description matchClass(ClassTree tree, VisitorState state) {
+      return buildDescription(tree)
+          .setMessage(
+              Arrays.stream(ThirdPartyLibrary.values())
+                  .map(
+                      lib ->
+                          String.join(
+                              ": ", lib.name(), String.valueOf(lib.isIntroductionAllowed(state))))
+                  .collect(joining(", ")))
+          .build();
+    }
+  }
+}

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

@@ -56,6 +56,7 @@ final class RefasterRulesTest {
           MultimapRules.class,
           NullRules.class,
           OptionalRules.class,
+          PreconditionsRules.class,
           PrimitiveRules.class,
           ReactorRules.class,
           RxJava2AdapterRules.class,

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

@@ -37,6 +37,12 @@ final class AssortedRulesTest implements RefasterRuleCollectionTestCase {
     return Preconditions.checkElementIndex(0, 1);
   }
 
+  void testCheckIndexConditional() {
+    if (1 < 0 || 1 >= 2) {
+      throw new IndexOutOfBoundsException();
+    }
+  }
+
   Map<RoundingMode, String> testCreateEnumMap() {
     return new HashMap<>();
   }

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

@@ -2,6 +2,7 @@ package tech.picnic.errorprone.refasterrules;
 
 import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static com.google.common.collect.Sets.toImmutableEnumSet;
+import static java.util.Objects.checkIndex;
 
 import com.google.common.base.Preconditions;
 import com.google.common.base.Splitter;
@@ -19,7 +20,6 @@ import java.util.EnumMap;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
-import java.util.Objects;
 import java.util.stream.Stream;
 import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 
@@ -38,7 +38,11 @@ final class AssortedRulesTest implements RefasterRuleCollectionTestCase {
   }
 
   int testCheckIndex() {
-    return Objects.checkIndex(0, 1);
+    return checkIndex(0, 1);
+  }
+
+  void testCheckIndexConditional() {
+    checkIndex(1, 2);
   }
 
   Map<RoundingMode, String> testCreateEnumMap() {

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

@@ -109,4 +109,14 @@ final class OptionalRulesTest implements RefasterRuleCollectionTestCase {
         Optional.of("baz").stream().min(String::compareTo),
         Optional.of("qux").stream().max(String::compareTo));
   }
+
+  ImmutableSet<Optional<String>> testOptionalFilter() {
+    return ImmutableSet.of(
+        Optional.of("foo").stream().filter(String::isEmpty).findFirst(),
+        Optional.of("bar").stream().filter(String::isEmpty).findAny());
+  }
+
+  Optional<String> testOptionalMap() {
+    return Optional.of(1).stream().map(String::valueOf).findAny();
+  }
 }

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

@@ -103,4 +103,13 @@ final class OptionalRulesTest implements RefasterRuleCollectionTestCase {
     return ImmutableSet.of(
         Optional.of("foo"), Optional.of("bar"), Optional.of("baz"), Optional.of("qux"));
   }
+
+  ImmutableSet<Optional<String>> testOptionalFilter() {
+    return ImmutableSet.of(
+        Optional.of("foo").filter(String::isEmpty), Optional.of("bar").filter(String::isEmpty));
+  }
+
+  Optional<String> testOptionalMap() {
+    return Optional.of(1).map(String::valueOf);
+  }
 }

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

@@ -0,0 +1,59 @@
+package tech.picnic.errorprone.refasterrules;
+
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class PreconditionsRulesTest implements RefasterRuleCollectionTestCase {
+  void testCheckArgument() {
+    if ("foo".isEmpty()) {
+      throw new IllegalArgumentException();
+    }
+  }
+
+  void testCheckArgumentWithMessage() {
+    if ("foo".isEmpty()) {
+      throw new IllegalArgumentException("The string is empty");
+    }
+  }
+
+  void testCheckElementIndexWithMessage() {
+    if (1 < 0 || 1 >= 2) {
+      throw new IndexOutOfBoundsException("My index");
+    }
+  }
+
+  void testCheckNotNull() {
+    if ("foo" == null) {
+      throw new NullPointerException();
+    }
+  }
+
+  void testCheckNotNullWithMessage() {
+    if ("foo" == null) {
+      throw new NullPointerException("The string is null");
+    }
+  }
+
+  void testCheckPositionIndex() {
+    if (1 < 0 || 1 > 2) {
+      throw new IndexOutOfBoundsException();
+    }
+  }
+
+  void testCheckPositionIndexWithMessage() {
+    if (1 < 0 || 1 > 2) {
+      throw new IndexOutOfBoundsException("My position");
+    }
+  }
+
+  void testCheckState() {
+    if ("foo".isEmpty()) {
+      throw new IllegalStateException();
+    }
+  }
+
+  void testCheckStateWithMessage() {
+    if ("foo".isEmpty()) {
+      throw new IllegalStateException("The string is empty");
+    }
+  }
+}

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

@@ -0,0 +1,47 @@
+package tech.picnic.errorprone.refasterrules;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkElementIndex;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkPositionIndex;
+import static com.google.common.base.Preconditions.checkState;
+
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class PreconditionsRulesTest implements RefasterRuleCollectionTestCase {
+  void testCheckArgument() {
+    checkArgument(!"foo".isEmpty());
+  }
+
+  void testCheckArgumentWithMessage() {
+    checkArgument(!"foo".isEmpty(), "The string is empty");
+  }
+
+  void testCheckElementIndexWithMessage() {
+    checkElementIndex(1, 2, "My index");
+  }
+
+  void testCheckNotNull() {
+    checkNotNull("foo");
+  }
+
+  void testCheckNotNullWithMessage() {
+    checkNotNull("foo", "The string is null");
+  }
+
+  void testCheckPositionIndex() {
+    checkPositionIndex(1, 2);
+  }
+
+  void testCheckPositionIndexWithMessage() {
+    checkPositionIndex(1, 2, "My position");
+  }
+
+  void testCheckState() {
+    checkState(!"foo".isEmpty());
+  }
+
+  void testCheckStateWithMessage() {
+    checkState(!"foo".isEmpty(), "The string is empty");
+  }
+}

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

@@ -3,8 +3,10 @@ package tech.picnic.errorprone.refasterrules;
 import static org.assertj.core.api.Assertions.assertThat;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import java.time.Duration;
+import java.util.HashMap;
 import java.util.Optional;
 import java.util.concurrent.Callable;
 import java.util.function.Supplier;
@@ -12,12 +14,14 @@ import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 import reactor.test.publisher.PublisherProbe;
+import reactor.util.context.Context;
+import reactor.util.function.Tuple2;
 import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 
 final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
   @Override
   public ImmutableSet<?> elidedTypesAndStaticImports() {
-    return ImmutableSet.of(assertThat(0));
+    return ImmutableSet.of(assertThat(0), HashMap.class, ImmutableMap.class);
   }
 
   ImmutableSet<Mono<?>> testMonoFromSupplier() {
@@ -35,6 +39,26 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
         Mono.fromSupplier(() -> Optional.of(2).orElse(null)));
   }
 
+  Mono<Tuple2<String, Integer>> testMonoZip() {
+    return Mono.just("foo").zipWith(Mono.just(1));
+  }
+
+  Mono<String> testMonoZipWithCombinator() {
+    return Mono.just("foo").zipWith(Mono.just(1), String::repeat);
+  }
+
+  Flux<Tuple2<String, Integer>> testFluxZip() {
+    return Flux.just("foo", "bar").zipWith(Flux.just(1, 2));
+  }
+
+  Flux<String> testFluxZipWithCombinator() {
+    return Flux.just("foo", "bar").zipWith(Flux.just(1, 2), String::repeat);
+  }
+
+  Flux<String> testFluxZipWithIterable() {
+    return Flux.just("foo", "bar").zipWithIterable(ImmutableSet.of(1, 2), String::repeat);
+  }
+
   Mono<Void> testMonoDeferredError() {
     return Mono.defer(() -> Mono.error(new IllegalStateException()));
   }
@@ -55,6 +79,10 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
     return Mono.empty().then(Mono.just("foo"));
   }
 
+  Flux<Integer> testFluxTake() {
+    return Flux.just(1, 2, 3).take(1);
+  }
+
   Mono<Integer> testMonoSwitchIfEmptyOfEmptyPublisher() {
     return Mono.just(1).switchIfEmpty(Mono.empty());
   }
@@ -83,7 +111,71 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
   }
 
   Flux<String> testMonoFlatMapToFlux() {
-    return Mono.just("foo").flatMapMany(s -> Mono.just(s + s));
+    return Mono.just("foo").flatMapMany(s -> Mono.fromSupplier(() -> s + s));
+  }
+
+  ImmutableSet<Mono<String>> testMonoMap() {
+    return ImmutableSet.of(
+        Mono.just("foo").flatMap(s -> Mono.just(s)),
+        Mono.just("bar").flatMap(s -> Mono.just(s.substring(1))));
+  }
+
+  ImmutableSet<Flux<Integer>> testFluxMap() {
+    return ImmutableSet.of(
+        Flux.just(1).concatMap(n -> Mono.just(n)),
+        Flux.just(1).concatMap(n -> Flux.just(n * 2)),
+        Flux.just(1).concatMap(n -> Mono.just(n), 3),
+        Flux.just(1).concatMap(n -> Flux.just(n * 2), 3),
+        Flux.just(1).concatMapDelayError(n -> Mono.just(n)),
+        Flux.just(1).concatMapDelayError(n -> Flux.just(n * 2)),
+        Flux.just(1).concatMapDelayError(n -> Mono.just(n), 3),
+        Flux.just(1).concatMapDelayError(n -> Flux.just(n * 2), 3),
+        Flux.just(1).flatMap(n -> Mono.just(n), 3),
+        Flux.just(1).flatMap(n -> Flux.just(n * 2), 3),
+        Flux.just(1).flatMap(n -> Mono.just(n), 3, 4),
+        Flux.just(1).flatMap(n -> Flux.just(n * 2), 3, 4),
+        Flux.just(1).flatMapDelayError(n -> Mono.just(n), 3, 4),
+        Flux.just(1).flatMapDelayError(n -> Flux.just(n * 2), 3, 4),
+        Flux.just(1).flatMapSequential(n -> Mono.just(n), 3),
+        Flux.just(1).flatMapSequential(n -> Flux.just(n * 2), 3),
+        Flux.just(1).flatMapSequential(n -> Mono.just(n), 3, 4),
+        Flux.just(1).flatMapSequential(n -> Flux.just(n * 2), 3, 4),
+        Flux.just(1).flatMapSequentialDelayError(n -> Mono.just(n), 3, 4),
+        Flux.just(1).flatMapSequentialDelayError(n -> Flux.just(n * 2), 3, 4),
+        Flux.just(1).switchMap(n -> Mono.just(n)),
+        Flux.just(1).switchMap(n -> Flux.just(n * 2)));
+  }
+
+  ImmutableSet<Mono<String>> testMonoMapNotNull() {
+    return ImmutableSet.of(
+        Mono.just("foo").flatMap(s -> Mono.justOrEmpty(s)),
+        Mono.just("bar").flatMap(s -> Mono.fromSupplier(() -> s.substring(1))));
+  }
+
+  ImmutableSet<Flux<Integer>> testFluxMapNotNull() {
+    return ImmutableSet.of(
+        Flux.just(1).concatMap(n -> Mono.justOrEmpty(n)),
+        Flux.just(1).concatMap(n -> Mono.fromSupplier(() -> n * 2)),
+        Flux.just(1).concatMap(n -> Mono.justOrEmpty(n), 3),
+        Flux.just(1).concatMap(n -> Mono.fromSupplier(() -> n * 2), 3),
+        Flux.just(1).concatMapDelayError(n -> Mono.justOrEmpty(n)),
+        Flux.just(1).concatMapDelayError(n -> Mono.fromSupplier(() -> n * 2)),
+        Flux.just(1).concatMapDelayError(n -> Mono.justOrEmpty(n), 3),
+        Flux.just(1).concatMapDelayError(n -> Mono.fromSupplier(() -> n * 2), 3),
+        Flux.just(1).flatMap(n -> Mono.justOrEmpty(n), 3),
+        Flux.just(1).flatMap(n -> Mono.fromSupplier(() -> n * 2), 3),
+        Flux.just(1).flatMap(n -> Mono.justOrEmpty(n), 3, 4),
+        Flux.just(1).flatMap(n -> Mono.fromSupplier(() -> n * 2), 3, 4),
+        Flux.just(1).flatMapDelayError(n -> Mono.justOrEmpty(n), 3, 4),
+        Flux.just(1).flatMapDelayError(n -> Mono.fromSupplier(() -> n * 2), 3, 4),
+        Flux.just(1).flatMapSequential(n -> Mono.justOrEmpty(n), 3),
+        Flux.just(1).flatMapSequential(n -> Mono.fromSupplier(() -> n * 2), 3),
+        Flux.just(1).flatMapSequential(n -> Mono.justOrEmpty(n), 3, 4),
+        Flux.just(1).flatMapSequential(n -> Mono.fromSupplier(() -> n * 2), 3, 4),
+        Flux.just(1).flatMapSequentialDelayError(n -> Mono.justOrEmpty(n), 3, 4),
+        Flux.just(1).flatMapSequentialDelayError(n -> Mono.fromSupplier(() -> n * 2), 3, 4),
+        Flux.just(1).switchMap(n -> Mono.justOrEmpty(n)),
+        Flux.just(1).switchMap(n -> Mono.fromSupplier(() -> n * 2)));
   }
 
   Flux<String> testMonoFlux() {
@@ -116,6 +208,14 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
         Flux.just(ImmutableList.of("bar")).concatMap(Flux::fromIterable, 2));
   }
 
+  Mono<Integer> testMonoDoOnError() {
+    return Mono.just(1).doOnError(IllegalArgumentException.class::isInstance, e -> {});
+  }
+
+  Flux<Integer> testFluxDoOnError() {
+    return Flux.just(1).doOnError(IllegalArgumentException.class::isInstance, e -> {});
+  }
+
   Mono<Integer> testMonoOnErrorComplete() {
     return Mono.just(1).onErrorResume(e -> Mono.empty());
   }
@@ -126,6 +226,67 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
         Flux.just(2).onErrorResume(e -> Flux.empty()));
   }
 
+  ImmutableSet<Mono<Integer>> testMonoOnErrorCompleteClass() {
+    return ImmutableSet.of(
+        Mono.just(1).onErrorComplete(IllegalArgumentException.class::isInstance),
+        Mono.just(2).onErrorResume(IllegalStateException.class, e -> Mono.empty()));
+  }
+
+  ImmutableSet<Flux<Integer>> testFluxOnErrorCompleteClass() {
+    return ImmutableSet.of(
+        Flux.just(1).onErrorComplete(IllegalArgumentException.class::isInstance),
+        Flux.just(2).onErrorResume(IllegalStateException.class, e -> Mono.empty()),
+        Flux.just(3).onErrorResume(AssertionError.class, e -> Flux.empty()));
+  }
+
+  Mono<Integer> testMonoOnErrorCompletePredicate() {
+    return Mono.just(1).onErrorResume(e -> e.getCause() == null, e -> Mono.empty());
+  }
+
+  ImmutableSet<Flux<Integer>> testFluxOnErrorCompletePredicate() {
+    return ImmutableSet.of(
+        Flux.just(1).onErrorResume(e -> e.getCause() == null, e -> Mono.empty()),
+        Flux.just(2).onErrorResume(e -> e.getCause() != null, e -> Flux.empty()));
+  }
+
+  Mono<Integer> testMonoOnErrorContinue() {
+    return Mono.just(1).onErrorContinue(IllegalArgumentException.class::isInstance, (e, v) -> {});
+  }
+
+  Flux<Integer> testFluxOnErrorContinue() {
+    return Flux.just(1).onErrorContinue(IllegalArgumentException.class::isInstance, (e, v) -> {});
+  }
+
+  Mono<Integer> testMonoOnErrorMap() {
+    return Mono.just(1).onErrorMap(IllegalArgumentException.class::isInstance, e -> e);
+  }
+
+  Flux<Integer> testFluxOnErrorMap() {
+    return Flux.just(1).onErrorMap(IllegalArgumentException.class::isInstance, e -> e);
+  }
+
+  Mono<Integer> testMonoOnErrorResume() {
+    return Mono.just(1)
+        .onErrorResume(IllegalArgumentException.class::isInstance, e -> Mono.just(2));
+  }
+
+  Flux<Integer> testFluxOnErrorResume() {
+    return Flux.just(1)
+        .onErrorResume(IllegalArgumentException.class::isInstance, e -> Flux.just(2));
+  }
+
+  Mono<Integer> testMonoOnErrorReturn() {
+    return Mono.just(1).onErrorReturn(IllegalArgumentException.class::isInstance, 2);
+  }
+
+  Flux<Integer> testFluxOnErrorReturn() {
+    return Flux.just(1).onErrorReturn(IllegalArgumentException.class::isInstance, 2);
+  }
+
+  ImmutableSet<Context> testContextEmpty() {
+    return ImmutableSet.of(Context.of(new HashMap<>()), Context.of(ImmutableMap.of()));
+  }
+
   ImmutableSet<PublisherProbe<Void>> testPublisherProbeEmpty() {
     return ImmutableSet.of(PublisherProbe.of(Mono.empty()), PublisherProbe.of(Flux.empty()));
   }

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

@@ -3,23 +3,29 @@ package tech.picnic.errorprone.refasterrules;
 import static com.google.common.collect.MoreCollectors.toOptional;
 import static java.util.function.Function.identity;
 import static org.assertj.core.api.Assertions.assertThat;
+import static reactor.function.TupleUtils.function;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import java.time.Duration;
+import java.util.HashMap;
 import java.util.Optional;
 import java.util.concurrent.Callable;
 import java.util.function.Supplier;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
+import reactor.function.TupleUtils;
 import reactor.test.StepVerifier;
 import reactor.test.publisher.PublisherProbe;
+import reactor.util.context.Context;
+import reactor.util.function.Tuple2;
 import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
 
 final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
   @Override
   public ImmutableSet<?> elidedTypesAndStaticImports() {
-    return ImmutableSet.of(assertThat(0));
+    return ImmutableSet.of(assertThat(0), HashMap.class, ImmutableMap.class);
   }
 
   ImmutableSet<Mono<?>> testMonoFromSupplier() {
@@ -37,6 +43,29 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
         Mono.defer(() -> Mono.justOrEmpty(Optional.of(2))));
   }
 
+  Mono<Tuple2<String, Integer>> testMonoZip() {
+    return Mono.zip(Mono.just("foo"), Mono.just(1));
+  }
+
+  Mono<String> testMonoZipWithCombinator() {
+    return Mono.zip(Mono.just("foo"), Mono.just(1)).map(TupleUtils.function(String::repeat));
+  }
+
+  Flux<Tuple2<String, Integer>> testFluxZip() {
+    return Flux.zip(Flux.just("foo", "bar"), Flux.just(1, 2));
+  }
+
+  Flux<String> testFluxZipWithCombinator() {
+    return Flux.zip(Flux.just("foo", "bar"), Flux.just(1, 2))
+        .map(TupleUtils.function(String::repeat));
+  }
+
+  Flux<String> testFluxZipWithIterable() {
+    return Flux.just("foo", "bar")
+        .zipWithIterable(ImmutableSet.of(1, 2))
+        .map(function(String::repeat));
+  }
+
   Mono<Void> testMonoDeferredError() {
     return Mono.error(() -> new IllegalStateException());
   }
@@ -57,6 +86,10 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
     return Mono.empty().thenReturn("foo");
   }
 
+  Flux<Integer> testFluxTake() {
+    return Flux.just(1, 2, 3).take(1, true);
+  }
+
   Mono<Integer> testMonoSwitchIfEmptyOfEmptyPublisher() {
     return Mono.just(1);
   }
@@ -83,7 +116,68 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
   }
 
   Flux<String> testMonoFlatMapToFlux() {
-    return Mono.just("foo").flatMap(s -> Mono.just(s + s)).flux();
+    return Mono.just("foo").flatMap(s -> Mono.fromSupplier(() -> s + s)).flux();
+  }
+
+  ImmutableSet<Mono<String>> testMonoMap() {
+    return ImmutableSet.of(Mono.just("foo").map(s -> s), Mono.just("bar").map(s -> s.substring(1)));
+  }
+
+  ImmutableSet<Flux<Integer>> testFluxMap() {
+    return ImmutableSet.of(
+        Flux.just(1).map(n -> n),
+        Flux.just(1).map(n -> n * 2),
+        Flux.just(1).map(n -> n),
+        Flux.just(1).map(n -> n * 2),
+        Flux.just(1).map(n -> n),
+        Flux.just(1).map(n -> n * 2),
+        Flux.just(1).map(n -> n),
+        Flux.just(1).map(n -> n * 2),
+        Flux.just(1).map(n -> n),
+        Flux.just(1).map(n -> n * 2),
+        Flux.just(1).map(n -> n),
+        Flux.just(1).map(n -> n * 2),
+        Flux.just(1).map(n -> n),
+        Flux.just(1).map(n -> n * 2),
+        Flux.just(1).map(n -> n),
+        Flux.just(1).map(n -> n * 2),
+        Flux.just(1).map(n -> n),
+        Flux.just(1).map(n -> n * 2),
+        Flux.just(1).map(n -> n),
+        Flux.just(1).map(n -> n * 2),
+        Flux.just(1).map(n -> n),
+        Flux.just(1).map(n -> n * 2));
+  }
+
+  ImmutableSet<Mono<String>> testMonoMapNotNull() {
+    return ImmutableSet.of(
+        Mono.just("foo").mapNotNull(s -> s), Mono.just("bar").mapNotNull(s -> s.substring(1)));
+  }
+
+  ImmutableSet<Flux<Integer>> testFluxMapNotNull() {
+    return ImmutableSet.of(
+        Flux.just(1).mapNotNull(n -> n),
+        Flux.just(1).mapNotNull(n -> n * 2),
+        Flux.just(1).mapNotNull(n -> n),
+        Flux.just(1).mapNotNull(n -> n * 2),
+        Flux.just(1).mapNotNull(n -> n),
+        Flux.just(1).mapNotNull(n -> n * 2),
+        Flux.just(1).mapNotNull(n -> n),
+        Flux.just(1).mapNotNull(n -> n * 2),
+        Flux.just(1).mapNotNull(n -> n),
+        Flux.just(1).mapNotNull(n -> n * 2),
+        Flux.just(1).mapNotNull(n -> n),
+        Flux.just(1).mapNotNull(n -> n * 2),
+        Flux.just(1).mapNotNull(n -> n),
+        Flux.just(1).mapNotNull(n -> n * 2),
+        Flux.just(1).mapNotNull(n -> n),
+        Flux.just(1).mapNotNull(n -> n * 2),
+        Flux.just(1).mapNotNull(n -> n),
+        Flux.just(1).mapNotNull(n -> n * 2),
+        Flux.just(1).mapNotNull(n -> n),
+        Flux.just(1).mapNotNull(n -> n * 2),
+        Flux.just(1).mapNotNull(n -> n),
+        Flux.just(1).mapNotNull(n -> n * 2));
   }
 
   Flux<String> testMonoFlux() {
@@ -116,6 +210,14 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
         Flux.just(ImmutableList.of("bar")).concatMapIterable(identity(), 2));
   }
 
+  Mono<Integer> testMonoDoOnError() {
+    return Mono.just(1).doOnError(IllegalArgumentException.class, e -> {});
+  }
+
+  Flux<Integer> testFluxDoOnError() {
+    return Flux.just(1).doOnError(IllegalArgumentException.class, e -> {});
+  }
+
   Mono<Integer> testMonoOnErrorComplete() {
     return Mono.just(1).onErrorComplete();
   }
@@ -124,6 +226,65 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
     return ImmutableSet.of(Flux.just(1).onErrorComplete(), Flux.just(2).onErrorComplete());
   }
 
+  ImmutableSet<Mono<Integer>> testMonoOnErrorCompleteClass() {
+    return ImmutableSet.of(
+        Mono.just(1).onErrorComplete(IllegalArgumentException.class),
+        Mono.just(2).onErrorComplete(IllegalStateException.class));
+  }
+
+  ImmutableSet<Flux<Integer>> testFluxOnErrorCompleteClass() {
+    return ImmutableSet.of(
+        Flux.just(1).onErrorComplete(IllegalArgumentException.class),
+        Flux.just(2).onErrorComplete(IllegalStateException.class),
+        Flux.just(3).onErrorComplete(AssertionError.class));
+  }
+
+  Mono<Integer> testMonoOnErrorCompletePredicate() {
+    return Mono.just(1).onErrorComplete(e -> e.getCause() == null);
+  }
+
+  ImmutableSet<Flux<Integer>> testFluxOnErrorCompletePredicate() {
+    return ImmutableSet.of(
+        Flux.just(1).onErrorComplete(e -> e.getCause() == null),
+        Flux.just(2).onErrorComplete(e -> e.getCause() != null));
+  }
+
+  Mono<Integer> testMonoOnErrorContinue() {
+    return Mono.just(1).onErrorContinue(IllegalArgumentException.class, (e, v) -> {});
+  }
+
+  Flux<Integer> testFluxOnErrorContinue() {
+    return Flux.just(1).onErrorContinue(IllegalArgumentException.class, (e, v) -> {});
+  }
+
+  Mono<Integer> testMonoOnErrorMap() {
+    return Mono.just(1).onErrorMap(IllegalArgumentException.class, e -> e);
+  }
+
+  Flux<Integer> testFluxOnErrorMap() {
+    return Flux.just(1).onErrorMap(IllegalArgumentException.class, e -> e);
+  }
+
+  Mono<Integer> testMonoOnErrorResume() {
+    return Mono.just(1).onErrorResume(IllegalArgumentException.class, e -> Mono.just(2));
+  }
+
+  Flux<Integer> testFluxOnErrorResume() {
+    return Flux.just(1).onErrorResume(IllegalArgumentException.class, e -> Flux.just(2));
+  }
+
+  Mono<Integer> testMonoOnErrorReturn() {
+    return Mono.just(1).onErrorReturn(IllegalArgumentException.class, 2);
+  }
+
+  Flux<Integer> testFluxOnErrorReturn() {
+    return Flux.just(1).onErrorReturn(IllegalArgumentException.class, 2);
+  }
+
+  ImmutableSet<Context> testContextEmpty() {
+    return ImmutableSet.of(Context.empty(), Context.empty());
+  }
+
   ImmutableSet<PublisherProbe<Void>> testPublisherProbeEmpty() {
     return ImmutableSet.of(PublisherProbe.empty(), PublisherProbe.empty());
   }

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

@@ -8,6 +8,7 @@ import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
 import java.time.OffsetDateTime;
+import java.time.OffsetTime;
 import java.time.Period;
 import java.time.ZoneId;
 import java.time.ZoneOffset;
@@ -35,10 +36,48 @@ final class TimeRulesTest implements RefasterRuleCollectionTestCase {
         ZoneId.from(ZoneOffset.UTC));
   }
 
+  ImmutableSet<LocalDate> testLocalDateOfInstant() {
+    return ImmutableSet.of(
+        Instant.EPOCH.atZone(ZoneId.of("Europe/Amsterdam")).toLocalDate(),
+        Instant.EPOCH.atOffset(ZoneOffset.UTC).toLocalDate(),
+        LocalDateTime.ofInstant(Instant.EPOCH, ZoneId.of("Europe/Berlin")).toLocalDate(),
+        OffsetDateTime.ofInstant(Instant.EPOCH, ZoneOffset.MIN).toLocalDate());
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeOfInstant() {
+    return ImmutableSet.of(
+        Instant.EPOCH.atZone(ZoneId.of("Europe/Amsterdam")).toLocalDateTime(),
+        Instant.EPOCH.atOffset(ZoneOffset.UTC).toLocalDateTime(),
+        OffsetDateTime.ofInstant(Instant.EPOCH, ZoneId.of("Europe/Berlin")).toLocalDateTime());
+  }
+
+  ImmutableSet<LocalTime> testLocalTimeOfInstant() {
+    return ImmutableSet.of(
+        Instant.EPOCH.atZone(ZoneId.of("Europe/Amsterdam")).toLocalTime(),
+        Instant.EPOCH.atOffset(ZoneOffset.UTC).toLocalTime(),
+        LocalDateTime.ofInstant(Instant.EPOCH, ZoneId.of("Europe/Berlin")).toLocalTime(),
+        OffsetDateTime.ofInstant(Instant.EPOCH, ZoneOffset.MIN).toLocalTime(),
+        OffsetTime.ofInstant(Instant.EPOCH, ZoneOffset.MAX).toLocalTime());
+  }
+
+  OffsetDateTime testOffsetDateTimeOfInstant() {
+    return Instant.EPOCH.atZone(ZoneOffset.UTC).toOffsetDateTime();
+  }
+
   OffsetDateTime testInstantAtOffset() {
     return OffsetDateTime.ofInstant(Instant.EPOCH, ZoneOffset.UTC);
   }
 
+  ImmutableSet<OffsetTime> testOffsetTimeOfInstant() {
+    return ImmutableSet.of(
+        OffsetDateTime.ofInstant(Instant.EPOCH, ZoneId.of("Europe/Amsterdam")).toOffsetTime(),
+        Instant.EPOCH.atOffset(ZoneOffset.UTC).toOffsetTime());
+  }
+
+  ZonedDateTime testInstantAtZone() {
+    return ZonedDateTime.ofInstant(Instant.EPOCH, ZoneOffset.UTC);
+  }
+
   Clock testUtcClock() {
     return Clock.system(ZoneOffset.UTC);
   }

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

@@ -8,6 +8,7 @@ import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
 import java.time.OffsetDateTime;
+import java.time.OffsetTime;
 import java.time.Period;
 import java.time.ZoneId;
 import java.time.ZoneOffset;
@@ -35,10 +36,48 @@ final class TimeRulesTest implements RefasterRuleCollectionTestCase {
         ZoneOffset.UTC);
   }
 
+  ImmutableSet<LocalDate> testLocalDateOfInstant() {
+    return ImmutableSet.of(
+        LocalDate.ofInstant(Instant.EPOCH, ZoneId.of("Europe/Amsterdam")),
+        LocalDate.ofInstant(Instant.EPOCH, ZoneOffset.UTC),
+        LocalDate.ofInstant(Instant.EPOCH, ZoneId.of("Europe/Berlin")),
+        LocalDate.ofInstant(Instant.EPOCH, ZoneOffset.MIN));
+  }
+
+  ImmutableSet<LocalDateTime> testLocalDateTimeOfInstant() {
+    return ImmutableSet.of(
+        LocalDateTime.ofInstant(Instant.EPOCH, ZoneId.of("Europe/Amsterdam")),
+        LocalDateTime.ofInstant(Instant.EPOCH, ZoneOffset.UTC),
+        LocalDateTime.ofInstant(Instant.EPOCH, ZoneId.of("Europe/Berlin")));
+  }
+
+  ImmutableSet<LocalTime> testLocalTimeOfInstant() {
+    return ImmutableSet.of(
+        LocalTime.ofInstant(Instant.EPOCH, ZoneId.of("Europe/Amsterdam")),
+        LocalTime.ofInstant(Instant.EPOCH, ZoneOffset.UTC),
+        LocalTime.ofInstant(Instant.EPOCH, ZoneId.of("Europe/Berlin")),
+        LocalTime.ofInstant(Instant.EPOCH, ZoneOffset.MIN),
+        LocalTime.ofInstant(Instant.EPOCH, ZoneOffset.MAX));
+  }
+
+  OffsetDateTime testOffsetDateTimeOfInstant() {
+    return OffsetDateTime.ofInstant(Instant.EPOCH, ZoneOffset.UTC);
+  }
+
   OffsetDateTime testInstantAtOffset() {
     return Instant.EPOCH.atOffset(ZoneOffset.UTC);
   }
 
+  ImmutableSet<OffsetTime> testOffsetTimeOfInstant() {
+    return ImmutableSet.of(
+        OffsetTime.ofInstant(Instant.EPOCH, ZoneId.of("Europe/Amsterdam")),
+        OffsetTime.ofInstant(Instant.EPOCH, ZoneOffset.UTC));
+  }
+
+  ZonedDateTime testInstantAtZone() {
+    return Instant.EPOCH.atZone(ZoneOffset.UTC);
+  }
+
   Clock testUtcClock() {
     return Clock.systemUTC();
   }

pom.xml

@@ -4,7 +4,7 @@
 
     <groupId>tech.picnic.error-prone-support</groupId>
     <artifactId>error-prone-support</artifactId>
-    <version>0.3.1-SNAPSHOT</version>
+    <version>0.5.1-SNAPSHOT</version>
     <packaging>pom</packaging>
 
     <name>Picnic :: Error Prone Support</name>
@@ -148,15 +148,15 @@
         <version.auto-service>1.0.1</version.auto-service>
         <version.auto-value>1.10</version.auto-value>
         <version.error-prone>${version.error-prone-orig}</version.error-prone>
-        <version.error-prone-fork>v${version.error-prone-orig}-picnic-3</version.error-prone-fork>
-        <version.error-prone-orig>2.15.0</version.error-prone-orig>
-        <version.error-prone-slf4j>0.1.15</version.error-prone-slf4j>
+        <version.error-prone-fork>v${version.error-prone-orig}-picnic-1</version.error-prone-fork>
+        <version.error-prone-orig>2.16</version.error-prone-orig>
+        <version.error-prone-slf4j>0.1.16</version.error-prone-slf4j>
         <version.guava-beta-checker>1.0</version.guava-beta-checker>
         <version.jdk>11</version.jdk>
         <version.maven>3.8.6</version.maven>
-        <version.mockito>4.8.0</version.mockito>
+        <version.mockito>4.8.1</version.mockito>
         <version.nopen-checker>1.0.1</version.nopen-checker>
-        <version.nullaway>0.10.2</version.nullaway>
+        <version.nullaway>0.10.4</version.nullaway>
         <!-- XXX: Two other dependencies are potentially of interest:
         `com.palantir.assertj-automation:assertj-refaster-rules` and
         `com.palantir.baseline:baseline-refaster-rules` contain Refaster rules
@@ -219,7 +219,7 @@
             <dependency>
                 <groupId>com.fasterxml.jackson</groupId>
                 <artifactId>jackson-bom</artifactId>
-                <version>2.13.4</version>
+                <version>2.13.4.20221013</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
@@ -243,11 +243,6 @@
                 <artifactId>auto-value-annotations</artifactId>
                 <version>${version.auto-value}</version>
             </dependency>
-            <dependency>
-                <groupId>com.google.code.findbugs</groupId>
-                <artifactId>jsr305</artifactId>
-                <version>3.0.2</version>
-            </dependency>
             <dependency>
                 <groupId>com.google.googlejavaformat</groupId>
                 <artifactId>google-java-format</artifactId>
@@ -282,7 +277,7 @@
             <dependency>
                 <groupId>com.newrelic.agent.java</groupId>
                 <artifactId>newrelic-api</artifactId>
-                <version>7.10.0</version>
+                <version>7.11.0</version>
             </dependency>
             <!-- Specified as a workaround for
             https://github.com/mojohaus/versions-maven-plugin/issues/244. -->
@@ -308,7 +303,7 @@
             <dependency>
                 <groupId>io.projectreactor</groupId>
                 <artifactId>reactor-bom</artifactId>
-                <version>2020.0.23</version>
+                <version>2020.0.24</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
@@ -320,12 +315,12 @@
             <dependency>
                 <groupId>io.swagger</groupId>
                 <artifactId>swagger-annotations</artifactId>
-                <version>1.6.7</version>
+                <version>1.6.8</version>
             </dependency>
             <dependency>
                 <groupId>io.swagger.core.v3</groupId>
                 <artifactId>swagger-annotations</artifactId>
-                <version>2.2.3</version>
+                <version>2.2.6</version>
             </dependency>
             <dependency>
                 <groupId>jakarta.servlet</groupId>
@@ -370,7 +365,7 @@
             <dependency>
                 <groupId>org.checkerframework</groupId>
                 <artifactId>checker-qual</artifactId>
-                <version>3.26.0</version>
+                <version>3.27.0</version>
             </dependency>
             <dependency>
                 <groupId>org.hamcrest</groupId>
@@ -416,7 +411,7 @@
             <dependency>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-test</artifactId>
-                <version>2.7.4</version>
+                <version>2.7.5</version>
             </dependency>
             <dependency>
                 <groupId>org.testng</groupId>
@@ -628,11 +623,15 @@
                                         </property>
                                         <property name="illegalClasses" value="com.mongodb.lang.Nullable">
                                             <!-- Instead, please use
-                                            `javax.annotation.Nullable`. -->
+                                            `org.jspecify.nullness.Nullable`. -->
                                         </property>
                                         <property name="illegalClasses" value="io.micrometer.core.lang.Nullable">
                                             <!-- Instead, please use
-                                            `javax.annotation.Nullable`. -->
+                                            `org.jspecify.nullness.Nullable`. -->
+                                        </property>
+                                        <property name="illegalClasses" value="javax.annotation.Nullable">
+                                            <!-- Instead, please use
+                                            `org.jspecify.nullness.Nullable`. -->
                                         </property>
                                         <property name="illegalClasses" value="javax.annotation.concurrent.Immutable">
                                             <!-- Instead, please use
@@ -648,7 +647,7 @@
                                         </property>
                                         <property name="illegalClasses" value="org.springframework.lang.Nullable">
                                             <!-- Instead, please use
-                                            `javax.annotation.Nullable`. -->
+                                            `org.jspecify.nullness.Nullable`. -->
                                         </property>
                                         <property name="illegalPkgs" value="com.amazonaws.annotation" />
                                         <property name="illegalPkgs" value="com.beust.jcommander.internal" />
@@ -784,7 +783,7 @@
                         <dependency>
                             <groupId>com.puppycrawl.tools</groupId>
                             <artifactId>checkstyle</artifactId>
-                            <version>10.3.4</version>
+                            <version>10.4</version>
                         </dependency>
                         <dependency>
                             <groupId>io.spring.nohttp</groupId>
@@ -1217,12 +1216,15 @@
                 <plugin>
                     <groupId>org.codehaus.mojo</groupId>
                     <artifactId>tidy-maven-plugin</artifactId>
-                    <version>1.1.0</version>
+                    <version>1.2.0</version>
                 </plugin>
                 <plugin>
                     <groupId>org.codehaus.mojo</groupId>
                     <artifactId>versions-maven-plugin</artifactId>
-                    <version>2.12.0</version>
+                    <version>2.13.0</version>
+                    <configuration>
+                        <updateBuildOutputTimestampPolicy>never</updateBuildOutputTimestampPolicy>
+                    </configuration>
                 </plugin>
                 <plugin>
                     <groupId>org.gaul</groupId>
@@ -1263,7 +1265,7 @@
                 <plugin>
                     <groupId>org.pitest</groupId>
                     <artifactId>pitest-maven</artifactId>
-                    <version>1.9.8</version>
+                    <version>1.9.9</version>
                     <configuration>
                         <excludedClasses>
                             <excludedClass>*.AutoValue_*</excludedClass>

refaster-compiler/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.3.1-SNAPSHOT</version>
+        <version>0.5.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>refaster-compiler</artifactId>
@@ -36,14 +36,14 @@
             <artifactId>auto-service-annotations</artifactId>
             <scope>provided</scope>
         </dependency>
-        <dependency>
-            <groupId>com.google.code.findbugs</groupId>
-            <artifactId>jsr305</artifactId>
-            <scope>provided</scope>
-        </dependency>
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.jspecify</groupId>
+            <artifactId>jspecify</artifactId>
+            <scope>provided</scope>
+        </dependency>
     </dependencies>
 </project>

refaster-compiler/src/main/java/tech/picnic/errorprone/refaster/plugin/RefasterRuleCompiler.java

@@ -12,6 +12,9 @@ import com.sun.tools.javac.api.BasicJavacTask;
  */
 @AutoService(Plugin.class)
 public final class RefasterRuleCompiler implements Plugin {
+  /** Instantiates a new {@link RefasterRuleCompiler} instance. */
+  public RefasterRuleCompiler() {}
+
   @Override
   public String getName() {
     return getClass().getSimpleName();

refaster-compiler/src/main/java/tech/picnic/errorprone/refaster/plugin/RefasterRuleCompilerTaskListener.java

@@ -28,10 +28,10 @@ import java.io.ObjectOutputStream;
 import java.io.UncheckedIOException;
 import java.lang.annotation.Annotation;
 import java.util.Map;
-import javax.annotation.Nullable;
 import javax.tools.FileObject;
 import javax.tools.JavaFileManager;
 import javax.tools.StandardLocation;
+import org.jspecify.nullness.Nullable;
 import tech.picnic.errorprone.refaster.AnnotatedCompositeCodeTransformer;
 
 /**
@@ -71,10 +71,10 @@ final class RefasterRuleCompilerTaskListener implements TaskListener {
 
   private ImmutableMap<ClassTree, CodeTransformer> compileRefasterRules(ClassTree tree) {
     ImmutableMap.Builder<ClassTree, CodeTransformer> rules = ImmutableMap.builder();
-    new TreeScanner<Void, ImmutableClassToInstanceMap<Annotation>>() {
-      @Nullable
+    new TreeScanner<@Nullable Void, ImmutableClassToInstanceMap<Annotation>>() {
       @Override
-      public Void visitClass(ClassTree node, ImmutableClassToInstanceMap<Annotation> annotations) {
+      public @Nullable Void visitClass(
+          ClassTree node, ImmutableClassToInstanceMap<Annotation> annotations) {
         ClassSymbol symbol = ASTHelpers.getSymbol(node);
 
         ImmutableList<CodeTransformer> transformers =
@@ -105,7 +105,7 @@ final class RefasterRuleCompilerTaskListener implements TaskListener {
 
   private static boolean containsRefasterRules(ClassTree tree) {
     return Boolean.TRUE.equals(
-        new TreeScanner<Boolean, Void>() {
+        new TreeScanner<Boolean, @Nullable Void>() {
           @Override
           public Boolean visitAnnotation(AnnotationTree node, @Nullable Void unused) {
             Symbol sym = ASTHelpers.getSymbol(node);

refaster-compiler/src/main/java/tech/picnic/errorprone/refaster/plugin/package-info.java

@@ -3,5 +3,5 @@
  * files on the classpath.
  */
 @com.google.errorprone.annotations.CheckReturnValue
-@javax.annotation.ParametersAreNonnullByDefault
+@org.jspecify.nullness.NullMarked
 package tech.picnic.errorprone.refaster.plugin;

refaster-runner/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.3.1-SNAPSHOT</version>
+        <version>0.5.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>refaster-runner</artifactId>
@@ -51,11 +51,6 @@
             <artifactId>auto-service-annotations</artifactId>
             <scope>provided</scope>
         </dependency>
-        <dependency>
-            <groupId>com.google.code.findbugs</groupId>
-            <artifactId>jsr305</artifactId>
-            <scope>provided</scope>
-        </dependency>
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
@@ -66,6 +61,11 @@
             <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>

refaster-runner/src/main/java/tech/picnic/errorprone/refaster/runner/Refaster.java

@@ -61,9 +61,10 @@ public final class Refaster extends BugChecker implements CompilationUnitTreeMat
 
   private static final long serialVersionUID = 1L;
 
+  @SuppressWarnings("serial" /* Concrete instance will be `Serializable`. */)
   private final CodeTransformer codeTransformer;
 
-  /** Instantiates the default {@link Refaster}. */
+  /** Instantiates a default {@link Refaster} instance. */
   public Refaster() {
     this(ErrorProneFlags.empty());
   }

refaster-runner/src/main/java/tech/picnic/errorprone/refaster/runner/package-info.java

@@ -1,4 +1,4 @@
 /** Exposes Refaster rules found on the classpath through a regular Error Prone check. */
 @com.google.errorprone.annotations.CheckReturnValue
-@javax.annotation.ParametersAreNonnullByDefault
+@org.jspecify.nullness.NullMarked
 package tech.picnic.errorprone.refaster.runner;

refaster-support/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.3.1-SNAPSHOT</version>
+        <version>0.5.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>refaster-support</artifactId>
@@ -51,21 +51,20 @@
             <artifactId>auto-value-annotations</artifactId>
             <scope>provided</scope>
         </dependency>
-        <dependency>
-            <groupId>com.google.code.findbugs</groupId>
-            <artifactId>jsr305</artifactId>
-            <scope>provided</scope>
-        </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>

refaster-support/src/main/java/tech/picnic/errorprone/refaster/AnnotatedCompositeCodeTransformer.java

@@ -42,6 +42,8 @@ public abstract class AnnotatedCompositeCodeTransformer implements CodeTransform
   private static final long serialVersionUID = 1L;
   private static final Splitter CLASS_NAME_SPLITTER = Splitter.on('.').limit(2);
 
+  AnnotatedCompositeCodeTransformer() {}
+
   abstract String packageName();
 
   abstract ImmutableList<CodeTransformer> transformers();

refaster-support/src/main/java/tech/picnic/errorprone/refaster/annotation/package-info.java

@@ -4,5 +4,5 @@
  * non-patch mode.
  */
 @com.google.errorprone.annotations.CheckReturnValue
-@javax.annotation.ParametersAreNonnullByDefault
+@org.jspecify.nullness.NullMarked
 package tech.picnic.errorprone.refaster.annotation;

refaster-support/src/main/java/tech/picnic/errorprone/refaster/matchers/IsArray.java

@@ -11,6 +11,9 @@ public final class IsArray implements Matcher<ExpressionTree> {
   private static final long serialVersionUID = 1L;
   private static final Matcher<ExpressionTree> DELEGATE = isArrayType();
 
+  /** Instantiates a new {@link IsArray} instance. */
+  public IsArray() {}
+
   @Override
   public boolean matches(ExpressionTree tree, VisitorState state) {
     return DELEGATE.matches(tree, state);

refaster-support/src/main/java/tech/picnic/errorprone/refaster/matchers/IsCharacter.java

@@ -14,6 +14,9 @@ public final class IsCharacter implements Matcher<ExpressionTree> {
   private static final Matcher<ExpressionTree> DELEGATE =
       anyOf(isSameType(CHAR_TYPE), isSameType(Character.class));
 
+  /** Instantiates a new {@link IsCharacter} instance. */
+  public IsCharacter() {}
+
   @Override
   public boolean matches(ExpressionTree tree, VisitorState state) {
     return DELEGATE.matches(tree, state);

refaster-support/src/main/java/tech/picnic/errorprone/refaster/matchers/ThrowsCheckedException.java

@@ -19,6 +19,9 @@ import java.util.Collection;
 public final class ThrowsCheckedException implements Matcher<ExpressionTree> {
   private static final long serialVersionUID = 1L;
 
+  /** Instantiates a new {@link ThrowsCheckedException} instance. */
+  public ThrowsCheckedException() {}
+
   @Override
   public boolean matches(ExpressionTree tree, VisitorState state) {
     return containsCheckedException(getThrownTypes(tree, state), state);

refaster-support/src/main/java/tech/picnic/errorprone/refaster/matchers/package-info.java

@@ -5,5 +5,5 @@
  * com.google.errorprone.refaster.annotation.NotMatches @NotMatches} annotations.
  */
 @com.google.errorprone.annotations.CheckReturnValue
-@javax.annotation.ParametersAreNonnullByDefault
+@org.jspecify.nullness.NullMarked
 package tech.picnic.errorprone.refaster.matchers;

refaster-support/src/main/java/tech/picnic/errorprone/refaster/package-info.java

@@ -1,4 +1,4 @@
 /** Assorted classes that aid the compilation or evaluation of Refaster rules. */
 @com.google.errorprone.annotations.CheckReturnValue
-@javax.annotation.ParametersAreNonnullByDefault
+@org.jspecify.nullness.NullMarked
 package tech.picnic.errorprone.refaster;

refaster-support/src/test/java/tech/picnic/errorprone/refaster/matchers/AbstractMatcherTestChecker.java

@@ -11,7 +11,7 @@ import com.sun.source.tree.ImportTree;
 import com.sun.source.tree.MethodTree;
 import com.sun.source.tree.Tree;
 import com.sun.source.util.TreeScanner;
-import javax.annotation.Nullable;
+import org.jspecify.nullness.Nullable;
 
 /**
  * An abstract {@link BugChecker} that reports a match for each expression matched by the given
@@ -31,10 +31,9 @@ abstract class AbstractMatcherTestChecker extends BugChecker implements Compilat
 
   @Override
   public Description matchCompilationUnit(CompilationUnitTree compilationUnit, VisitorState state) {
-    new TreeScanner<Void, Void>() {
-      @Nullable
+    new TreeScanner<@Nullable Void, @Nullable Void>() {
       @Override
-      public Void scan(Tree tree, @Nullable Void unused) {
+      public @Nullable Void scan(Tree tree, @Nullable Void unused) {
         if (tree instanceof ExpressionTree && delegate.matches((ExpressionTree) tree, state)) {
           state.reportMatch(
               Description.builder(tree, canonicalName(), null, defaultSeverity(), message())
@@ -44,9 +43,8 @@ abstract class AbstractMatcherTestChecker extends BugChecker implements Compilat
         return super.scan(tree, unused);
       }
 
-      @Nullable
       @Override
-      public Void visitImport(ImportTree node, @Nullable Void unused) {
+      public @Nullable Void visitImport(ImportTree node, @Nullable Void unused) {
         /*
          * We're not interested in matching import statements. While components of these
          * can be `ExpressionTree`s, they will never be matched by Refaster.
@@ -54,9 +52,8 @@ abstract class AbstractMatcherTestChecker extends BugChecker implements Compilat
         return null;
       }
 
-      @Nullable
       @Override
-      public Void visitMethod(MethodTree node, @Nullable Void unused) {
+      public @Nullable Void visitMethod(MethodTree node, @Nullable Void unused) {
         /*
          * We're not interested in matching e.g. parameter and return type declarations. While these
          * can be `ExpressionTree`s, they will never be matched by Refaster.

refaster-test-support/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.3.1-SNAPSHOT</version>
+        <version>0.5.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>refaster-test-support</artifactId>
@@ -45,15 +45,15 @@
             <artifactId>auto-service-annotations</artifactId>
             <scope>provided</scope>
         </dependency>
-        <dependency>
-            <groupId>com.google.code.findbugs</groupId>
-            <artifactId>jsr305</artifactId>
-            <scope>provided</scope>
-        </dependency>
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.jspecify</groupId>
+            <artifactId>jspecify</artifactId>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>

refaster-test-support/src/main/java/tech/picnic/errorprone/refaster/test/RefasterRuleCollection.java

@@ -44,7 +44,7 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.regex.Pattern;
-import javax.annotation.Nullable;
+import org.jspecify.nullness.Nullable;
 import tech.picnic.errorprone.refaster.runner.CodeTransformers;
 import tech.picnic.errorprone.refaster.runner.Refaster;
 
@@ -239,16 +239,15 @@ public final class RefasterRuleCollection extends BugChecker implements Compilat
     return value.substring(index + 1);
   }
 
-  private class UnexpectedMatchReporter extends TreeScanner<Void, VisitorState> {
+  private class UnexpectedMatchReporter extends TreeScanner<@Nullable Void, VisitorState> {
     private final ImmutableRangeMap<Integer, String> indexedMatches;
 
     UnexpectedMatchReporter(ImmutableRangeMap<Integer, String> indexedMatches) {
       this.indexedMatches = indexedMatches;
     }
 
-    @Nullable
     @Override
-    public Void visitMethod(MethodTree tree, VisitorState state) {
+    public @Nullable Void visitMethod(MethodTree tree, VisitorState state) {
       if (!ASTHelpers.isGeneratedConstructor(tree)) {
         getRuleUnderTest(tree, state)
             .ifPresent(ruleUnderTest -> reportUnexpectedMatches(tree, ruleUnderTest, state));

refaster-test-support/src/main/java/tech/picnic/errorprone/refaster/test/package-info.java

@@ -1,4 +1,4 @@
 /** Opinionated utilities for the testing of Refaster rules. */
 @com.google.errorprone.annotations.CheckReturnValue
-@javax.annotation.ParametersAreNonnullByDefault
+@org.jspecify.nullness.NullMarked
 package tech.picnic.errorprone.refaster.test;

refaster-test-support/src/test/java/tech/picnic/errorprone/refaster/test/ValidRules.java

@@ -8,7 +8,7 @@ import com.google.errorprone.refaster.annotation.BeforeTemplate;
 import com.google.errorprone.refaster.annotation.Placeholder;
 import com.google.errorprone.refaster.annotation.UseImportPolicy;
 import java.util.Set;
-import javax.annotation.Nullable;
+import org.jspecify.nullness.Nullable;
 
 /** Refaster rule collection to validate that having no violations works as expected. */
 final class ValidRules {