Upgrade Project Reactor 2024.0.4 -> 2024.0.5 (#1643)

See:
- https://github.com/reactor/reactor/releases/tag/2024.0.5
- https://github.com/reactor/reactor/compare/2024.0.4...2024.0.5

.github/workflows/build.yml

@@ -26,7 +26,7 @@ jobs:
     continue-on-error: ${{ matrix.experimental }}
     steps:
       - name: Install Harden-Runner
-        uses: step-security/harden-runner@4d991eb9b905ef189e4c376166672c3f2f230481 # v2.11.0
+        uses: step-security/harden-runner@c6295a65d1254861815972266d5933fd6e532bdf # v2.11.1
         with:
           disable-sudo: true
           egress-policy: block

.github/workflows/codeql.yml

@@ -22,7 +22,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Install Harden-Runner
-        uses: step-security/harden-runner@4d991eb9b905ef189e4c376166672c3f2f230481 # v2.11.0
+        uses: step-security/harden-runner@c6295a65d1254861815972266d5933fd6e532bdf # v2.11.1
         with:
           disable-sudo: true
           egress-policy: block

.github/workflows/deploy-website.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Install Harden-Runner
-        uses: step-security/harden-runner@4d991eb9b905ef189e4c376166672c3f2f230481 # v2.11.0
+        uses: step-security/harden-runner@c6295a65d1254861815972266d5933fd6e532bdf # v2.11.1
         with:
           disable-sudo: true
           egress-policy: block
@@ -75,7 +75,7 @@ jobs:
       url: ${{ steps.deployment.outputs.page_url }}
     steps:
       - name: Install Harden-Runner
-        uses: step-security/harden-runner@4d991eb9b905ef189e4c376166672c3f2f230481 # v2.11.0
+        uses: step-security/harden-runner@c6295a65d1254861815972266d5933fd6e532bdf # v2.11.1
         with:
           disable-sudo: true
           egress-policy: block

.github/workflows/openssf-scorecard.yml

@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Install Harden-Runner
-        uses: step-security/harden-runner@4d991eb9b905ef189e4c376166672c3f2f230481 # v2.11.0
+        uses: step-security/harden-runner@c6295a65d1254861815972266d5933fd6e532bdf # v2.11.1
         with:
           disable-sudo: true
           egress-policy: block

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

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Install Harden-Runner
-        uses: step-security/harden-runner@4d991eb9b905ef189e4c376166672c3f2f230481 # v2.11.0
+        uses: step-security/harden-runner@c6295a65d1254861815972266d5933fd6e532bdf # v2.11.1
         with:
           disable-sudo: true
           egress-policy: block

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

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Install Harden-Runner
-        uses: step-security/harden-runner@4d991eb9b905ef189e4c376166672c3f2f230481 # v2.11.0
+        uses: step-security/harden-runner@c6295a65d1254861815972266d5933fd6e532bdf # v2.11.1
         with:
           disable-sudo: true
           egress-policy: block

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

@@ -22,7 +22,7 @@ jobs:
         integration-test: [ "checkstyle", "metrics", "prometheus-java-client" ]
     steps:
       - name: Install Harden-Runner
-        uses: step-security/harden-runner@4d991eb9b905ef189e4c376166672c3f2f230481 # v2.11.0
+        uses: step-security/harden-runner@c6295a65d1254861815972266d5933fd6e532bdf # v2.11.1
         with:
           disable-sudo: true
           egress-policy: block

.github/workflows/sonarcloud.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Install Harden-Runner
-        uses: step-security/harden-runner@4d991eb9b905ef189e4c376166672c3f2f230481 # v2.11.0
+        uses: step-security/harden-runner@c6295a65d1254861815972266d5933fd6e532bdf # v2.11.1
         with:
           disable-sudo: true
           egress-policy: block

documentation-support/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.21.1-SNAPSHOT</version>
+        <version>0.22.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>documentation-support</artifactId>

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

@@ -2,6 +2,7 @@ package tech.picnic.errorprone.documentation;
 
 import static com.google.errorprone.matchers.Matchers.instanceMethod;
 import static com.google.errorprone.matchers.method.MethodMatchers.staticMethod;
+import static java.util.Objects.requireNonNull;
 import static java.util.function.Predicate.not;
 
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
@@ -167,7 +168,10 @@ public final class BugPatternTestExtractor implements Extractor<BugPatternTestCa
          * is safe, because this code is guarded by an earlier call to `#getClassUnderTest(..)`,
          * which ensures that `tree` is part of a longer method invocation chain.
          */
-        MethodInvocationTree inputTree = (MethodInvocationTree) ASTHelpers.getReceiver(tree);
+        MethodInvocationTree inputTree =
+            (MethodInvocationTree)
+                requireNonNull(
+                    ASTHelpers.getReceiver(tree), "Instance method invocation must have receiver");
 
         String path = ASTHelpers.constValue(inputTree.getArguments().get(0), String.class);
         Optional<String> inputCode = getSourceCode(inputTree);

error-prone-contrib/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.21.1-SNAPSHOT</version>
+        <version>0.22.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>error-prone-contrib</artifactId>
@@ -62,6 +62,16 @@
             <artifactId>auto-value-annotations</artifactId>
             <scope>provided</scope>
         </dependency>
+        <!-- XXX: JSR-305 (meta-)annotation usage by some dependencies triggers
+        NullAway to attempt to load said annotations. As such some modules
+        require these annotations to be on the classpath. Periodically review
+        whether we can drop this dependeny declaration. See
+        https://github.com/uber/NullAway/issues/1171. -->
+        <dependency>
+            <groupId>com.google.code.findbugs</groupId>
+            <artifactId>jsr305</artifactId>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>com.google.errorprone</groupId>
             <artifactId>error_prone_annotation</artifactId>

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

@@ -11,6 +11,7 @@ import static com.google.errorprone.matchers.Matchers.not;
 import static com.google.errorprone.matchers.Matchers.returnStatement;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
 import static com.google.errorprone.matchers.Matchers.toType;
+import static java.util.Objects.requireNonNull;
 import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
@@ -79,7 +80,10 @@ public final class DirectReturn extends BugChecker implements BlockTreeMatcher {
       return Description.NO_MATCH;
     }
 
-    Symbol variableSymbol = ASTHelpers.getSymbol(((ReturnTree) finalStatement).getExpression());
+    Symbol variableSymbol =
+        requireNonNull(
+            ASTHelpers.getSymbol(((ReturnTree) finalStatement).getExpression()),
+            "Missing symbol for returned variable");
     StatementTree precedingStatement = statements.get(statements.size() - 2);
 
     return tryMatchAssignment(variableSymbol, precedingStatement)

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

@@ -18,6 +18,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMultiset;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableTable;
+import com.google.common.collect.Iterables;
 import com.google.errorprone.BugPattern;
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.bugpatterns.BugChecker;
@@ -33,6 +34,8 @@ import com.sun.source.tree.MethodInvocationTree;
 import com.sun.source.tree.MethodTree;
 import com.sun.tools.javac.code.Symbol.MethodSymbol;
 import com.sun.tools.javac.code.Symbol.VarSymbol;
+import com.sun.tools.javac.code.Type;
+import com.sun.tools.javac.code.Types;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
@@ -178,30 +181,45 @@ public final class ExplicitArgumentEnumeration extends BugChecker
                 state.getTypes())
             .collect(toImmutableList());
 
-    /*
-     * If all overloads have a single parameter, and at least one of them is a varargs method, then
-     * we assume that unwrapping the iterable argument will cause a suitable overload to be invoked.
-     * (Note that there may be multiple varargs overloads, either with different parameter types, or
-     * due to method overriding; this check does not attempt to determine which exact method or
-     * overload will be invoked as a result of the suggested simplification.)
-     *
-     * Note that this is a (highly!) imperfect heuristic, but it is sufficient to prevent e.g.
-     * unwrapping of arguments to `org.jooq.impl.DSL#row`, which can cause the expression's return
-     * type to change from `RowN` to (e.g.) `Row2`.
-     */
-    // XXX: There are certainly cases where it _would_ be nice to unwrap the arguments to
-    // `org.jooq.impl.DSL#row(Collection<?>)`. Look into this.
-    // XXX: Ideally we do check that one of the overloads accepts the unwrapped arguments.
-    // XXX: Ideally we validate that eligible overloads have compatible return types.
-    boolean hasLikelySuitableVarargsOverload =
-        overloads.stream().allMatch(m -> m.params().size() == 1)
-            && overloads.stream().anyMatch(MethodSymbol::isVarArgs);
-
-    return hasLikelySuitableVarargsOverload
+    return hasLikelySuitableVarargsOverload(method, overloads, state)
         ? Optional.of(SourceCode.unwrapMethodInvocation(argument, state))
         : Optional.empty();
   }
 
+  /**
+   * Tells whether it is likely that, if the argument to the given method is unwrapped, a suitable
+   * varargs overload will be invoked instead.
+   *
+   * <p>If all overloads have a single parameter, and at least one of them is a suitably-typed
+   * varargs method, then we assume that unwrapping the iterable argument will cause a suitable
+   * overload to be invoked. (Note that there may be multiple varargs overloads due to method
+   * overriding; this check does not attempt to determine which exact method or overload will be
+   * invoked as a result of the suggested simplification.)
+   *
+   * <p>Note that this is a (highly!) imperfect heuristic, but it is sufficient to prevent e.g.
+   * unwrapping of arguments to `org.jooq.impl.DSL#row`, which can cause the expression's return
+   * type to change from `RowN` to (e.g.) `Row2`.
+   */
+  // XXX: There are certainly cases where it _would_ be nice to unwrap the arguments to
+  // `org.jooq.impl.DSL#row(Collection<?>)`. Look into this.
+  // XXX: Ideally we validate that eligible overloads have compatible return types.
+  private static boolean hasLikelySuitableVarargsOverload(
+      MethodSymbol method, ImmutableList<MethodSymbol> overloads, VisitorState state) {
+    Types types = state.getTypes();
+    // XXX: This logic is fragile, as it assumes that the method parameter's type is of the form
+    // `X<T>`, where `T` is the type of the explicitly enumerated values passed to the expression to
+    // be unwrapped. This should generally hold, given the types returned by the
+    // `EXPLICIT_ITERABLE_CREATOR` expressions: `Iterable<T>`, `List<T>`, `Set<T>`, etc.
+    Type parameterType =
+        Iterables.getOnlyElement(
+            Iterables.getOnlyElement(method.getParameters()).type.getTypeArguments());
+    return overloads.stream().allMatch(m -> m.params().size() == 1)
+        && overloads.stream()
+            .filter(MethodSymbol::isVarArgs)
+            .map(m -> types.elemtype(Iterables.getOnlyElement(m.getParameters()).type))
+            .anyMatch(varArgsType -> types.containsType(parameterType, varArgsType));
+  }
+
   private static Optional<SuggestedFix> trySuggestCallingCustomAlternative(
       MethodInvocationTree tree, MethodInvocationTree argument, VisitorState state) {
     return ALTERNATIVE_METHODS.rowMap().entrySet().stream()

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

@@ -17,6 +17,7 @@ import static com.google.errorprone.matchers.Matchers.isSameType;
 import static com.google.errorprone.matchers.Matchers.methodHasParameters;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
 import static com.google.errorprone.matchers.Matchers.toType;
+import static java.util.Objects.requireNonNull;
 import static java.util.function.Predicate.not;
 import static java.util.stream.Collectors.joining;
 import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
@@ -129,7 +130,10 @@ public final class JUnitValueSource extends BugChecker implements MethodTreeMatc
       return Description.NO_MATCH;
     }
 
-    Type parameterType = ASTHelpers.getType(Iterables.getOnlyElement(tree.getParameters()));
+    Type parameterType =
+        requireNonNull(
+            ASTHelpers.getType(Iterables.getOnlyElement(tree.getParameters())),
+            "Missing type for method parameter");
 
     return findMethodSourceAnnotation(tree, state)
         .flatMap(
@@ -173,7 +177,9 @@ public final class JUnitValueSource extends BugChecker implements MethodTreeMatc
 
   private static Optional<MethodTree> findMatchingSibling(
       MethodTree tree, Predicate<? super MethodTree> predicate, VisitorState state) {
-    return state.findEnclosing(ClassTree.class).getMembers().stream()
+    return requireNonNull(state.findEnclosing(ClassTree.class), "No class enclosing method")
+        .getMembers()
+        .stream()
         .filter(MethodTree.class::isInstance)
         .map(MethodTree.class::cast)
         .filter(not(tree::equals))

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

@@ -5,6 +5,7 @@ import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
 import static com.google.errorprone.BugPattern.StandardTags.SIMPLIFICATION;
 import static com.google.errorprone.matchers.Matchers.anyOf;
 import static com.google.errorprone.matchers.Matchers.instanceMethod;
+import static java.util.Objects.requireNonNull;
 import static tech.picnic.errorprone.utils.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
@@ -86,7 +87,9 @@ public final class NonEmptyMono extends BugChecker implements MethodInvocationTr
       return Description.NO_MATCH;
     }
 
-    ExpressionTree receiver = ASTHelpers.getReceiver(tree);
+    ExpressionTree receiver =
+        requireNonNull(
+            ASTHelpers.getReceiver(tree), "Instance method invocation must have receiver");
     if (!NON_EMPTY_MONO.matches(receiver, state)) {
       return Description.NO_MATCH;
     }

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

@@ -204,6 +204,11 @@ final class AssertJEnumerableRules {
       return enumAssert.hasSize(iterable.length);
     }
 
+    @BeforeTemplate
+    EnumerableAssert<?, S> before(EnumerableAssert<?, S> enumAssert, CharSequence iterable) {
+      return enumAssert.hasSize(iterable.length());
+    }
+
     @AfterTemplate
     EnumerableAssert<?, S> after(EnumerableAssert<?, S> enumAssert, Iterable<E> iterable) {
       return enumAssert.hasSameSizeAs(iterable);

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

@@ -55,7 +55,6 @@ import reactor.util.function.Tuple2;
 import tech.picnic.errorprone.refaster.annotation.Description;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 import tech.picnic.errorprone.refaster.matchers.IsEmpty;
-import tech.picnic.errorprone.refaster.matchers.IsFunctionReturningMono;
 import tech.picnic.errorprone.refaster.matchers.IsIdentityOperation;
 import tech.picnic.errorprone.refaster.matchers.ThrowsCheckedException;
 
@@ -516,8 +515,14 @@ final class ReactorRules {
           mono.switchIfEmpty(Mono.empty()), mono.flux().next(), mono.flux().singleOrEmpty());
     }
 
+    // XXX: Consider filing a SonarCloud issue for the S2637 false positive.
     @BeforeTemplate
-    Mono<@Nullable Void> before2(Mono<@Nullable Void> mono) {
+    @SuppressWarnings({
+      "java:S2637" /* False positive: result is never `null`. */,
+      "java:S4968" /* Result may be `Mono<Void>`. */,
+      "key-to-resolve-AnnotationUseStyle-and-TrailingComment-check-conflict"
+    })
+    Mono<? extends @Nullable Void> before2(Mono<@Nullable Void> mono) {
       return Refaster.anyOf(mono.ignoreElement(), mono.then());
     }
 
@@ -549,152 +554,6 @@ final class ReactorRules {
     }
   }
 
-  /**
-   * Don't unnecessarily transform a {@link Flux#using(Callable, Function)} to a mono, instead use
-   * the equivalent API provided by {@link Mono}.
-   */
-  static final class MonoUsing<
-      D extends AutoCloseable, T, P extends Publisher<? extends T>, M extends Mono<? extends T>> {
-    @BeforeTemplate
-    Mono<T> before(
-        Callable<D> resourceSupplier,
-        @Matches(IsFunctionReturningMono.class) Function<D, P> sourceSupplier) {
-      return Flux.using(resourceSupplier, sourceSupplier).single();
-    }
-
-    @AfterTemplate
-    Mono<T> after(Callable<D> resourceSupplier, Function<D, M> sourceSupplier) {
-      return Mono.using(resourceSupplier, sourceSupplier);
-    }
-  }
-
-  /**
-   * Don't unnecessarily transform a {@link Flux#using(Callable, Function, boolean)} to a mono,
-   * instead use the equivalent API provided by {@link Mono}.
-   */
-  static final class MonoUsingEager<
-      D extends AutoCloseable, T, P extends Publisher<? extends T>, M extends Mono<? extends T>> {
-    @BeforeTemplate
-    Mono<T> before(
-        Callable<D> resourceSupplier,
-        @Matches(IsFunctionReturningMono.class) Function<D, P> sourceSupplier,
-        boolean eager) {
-      return Flux.using(resourceSupplier, sourceSupplier, eager).single();
-    }
-
-    @AfterTemplate
-    Mono<T> after(Callable<D> resourceSupplier, Function<D, M> sourceSupplier, boolean eager) {
-      return Mono.using(resourceSupplier, sourceSupplier, eager);
-    }
-  }
-
-  /**
-   * Don't unnecessarily transform a {@link Flux#using(Callable, Function, Consumer)} to a mono,
-   * instead use the equivalent API provided by {@link Mono}.
-   */
-  static final class MonoUsing2<
-      D, T, P extends Publisher<? extends T>, M extends Mono<? extends T>> {
-    @BeforeTemplate
-    Mono<T> before(
-        Callable<D> resourceSupplier,
-        @Matches(IsFunctionReturningMono.class) Function<D, P> sourceSupplier,
-        Consumer<D> resourceCleanup) {
-      return Flux.using(resourceSupplier, sourceSupplier, resourceCleanup).single();
-    }
-
-    @AfterTemplate
-    Mono<T> after(
-        Callable<D> resourceSupplier, Function<D, M> sourceSupplier, Consumer<D> resourceCleanup) {
-      return Mono.using(resourceSupplier, sourceSupplier, resourceCleanup);
-    }
-  }
-
-  /**
-   * Don't unnecessarily transform a {@link Flux#using(Callable, Function, Consumer, boolean)} to a
-   * mono, instead use the equivalent API provided by {@link Mono}.
-   */
-  static final class MonoUsing2Eager<
-      D, T, P extends Publisher<? extends T>, M extends Mono<? extends T>> {
-    @BeforeTemplate
-    Mono<T> before(
-        Callable<D> resourceSupplier,
-        @Matches(IsFunctionReturningMono.class) Function<D, P> sourceSupplier,
-        Consumer<D> resourceCleanup,
-        boolean eager) {
-      return Flux.using(resourceSupplier, sourceSupplier, resourceCleanup, eager).single();
-    }
-
-    @AfterTemplate
-    Mono<T> after(
-        Callable<D> resourceSupplier,
-        Function<D, M> sourceSupplier,
-        Consumer<D> resourceCleanup,
-        boolean eager) {
-      return Mono.using(resourceSupplier, sourceSupplier, resourceCleanup, eager);
-    }
-  }
-
-  /**
-   * Don't unnecessarily transform a {@link Flux#usingWhen(Publisher, Function, Function)} to a
-   * mono, instead use the equivalent API provided by {@link Mono}.
-   */
-  static final class MonoUsingWhen<
-      D,
-      T,
-      P extends Publisher<? extends T>,
-      P2 extends Publisher<?>,
-      M extends Mono<? extends T>> {
-    @BeforeTemplate
-    Mono<T> before(
-        Publisher<D> resourceSupplier,
-        @Matches(IsFunctionReturningMono.class) Function<D, P> resourceClosure,
-        Function<D, P2> asyncCleanup) {
-      return Flux.usingWhen(resourceSupplier, resourceClosure, asyncCleanup).single();
-    }
-
-    @AfterTemplate
-    Mono<T> after(
-        Publisher<D> resourceSupplier,
-        Function<D, M> resourceClosure,
-        Function<D, P2> asyncCleanup) {
-      return Mono.usingWhen(resourceSupplier, resourceClosure, asyncCleanup);
-    }
-  }
-
-  /**
-   * Don't unnecessarily transform a {@link Flux#usingWhen(Publisher, Function, Function,
-   * BiFunction, Function)} to a mono, instead use the equivalent API provided by {@link Mono}.
-   */
-  static final class MonoUsingWhen2<
-      D,
-      T,
-      P extends Publisher<? extends T>,
-      P2 extends Publisher<?>,
-      M extends Mono<? extends T>> {
-    @BeforeTemplate
-    Mono<T> before(
-        Publisher<D> resourceSupplier,
-        @Matches(IsFunctionReturningMono.class) Function<D, P> resourceClosure,
-        Function<D, P2> asyncComplete,
-        BiFunction<D, ? super Throwable, P2> asyncError,
-        Function<D, P2> asyncCancel) {
-      return Flux.usingWhen(
-              resourceSupplier, resourceClosure, asyncComplete, asyncError, asyncCancel)
-          .single();
-    }
-
-    @AfterTemplate
-    Mono<T> after(
-        Publisher<D> resourceSupplier,
-        Function<D, M> resourceClosure,
-        Function<D, P2> asyncComplete,
-        BiFunction<D, ? super Throwable, ? extends Publisher<?>> asyncError,
-        Function<D, P2> asyncCancel) {
-      return Mono.usingWhen(
-          resourceSupplier, resourceClosure, asyncComplete, asyncError, asyncCancel);
-    }
-  }
-
   /** Don't unnecessarily pass an empty publisher to {@link Flux#switchIfEmpty(Publisher)}. */
   static final class FluxSwitchIfEmptyOfEmptyPublisher<T> {
     @BeforeTemplate
@@ -1092,7 +951,8 @@ final class ReactorRules {
   /** Prefer direct invocation of {@link Mono#then()}} over more contrived alternatives. */
   static final class MonoThen<T> {
     @BeforeTemplate
-    Mono<@Nullable Void> before(Mono<T> mono) {
+    @SuppressWarnings("java:S4968" /* Result may be `Mono<Void>`. */)
+    Mono<? extends @Nullable Void> before(Mono<T> mono) {
       return Refaster.anyOf(
           mono.ignoreElement().then(),
           mono.flux().then(),
@@ -1101,7 +961,8 @@ final class ReactorRules {
     }
 
     @AfterTemplate
-    Mono<@Nullable Void> after(Mono<T> mono) {
+    @SuppressWarnings("java:S4968" /* Result may be `Mono<Void>`. */)
+    Mono<? extends @Nullable Void> after(Mono<T> mono) {
       return mono.then();
     }
   }
@@ -1109,17 +970,25 @@ final class ReactorRules {
   /** Avoid vacuous invocations of {@link Flux#ignoreElements()}. */
   static final class FluxThen<T> {
     @BeforeTemplate
-    Mono<@Nullable Void> before(Flux<T> flux) {
+    @SuppressWarnings("java:S4968" /* Result may be `Mono<Void>`. */)
+    Mono<? extends @Nullable Void> before(Flux<T> flux) {
       return flux.ignoreElements().then();
     }
 
+    // XXX: Consider filing a SonarCloud issue for the S2637 false positive.
     @BeforeTemplate
-    Mono<@Nullable Void> before2(Flux<@Nullable Void> flux) {
+    @SuppressWarnings({
+      "java:S2637" /* False positive: result is never `null`. */,
+      "java:S4968" /* Result may be `Mono<Void>`. */,
+      "key-to-resolve-AnnotationUseStyle-and-TrailingComment-check-conflict"
+    })
+    Mono<? extends @Nullable Void> before2(Flux<@Nullable Void> flux) {
       return flux.ignoreElements();
     }
 
     @AfterTemplate
-    Mono<@Nullable Void> after(Flux<T> flux) {
+    @SuppressWarnings("java:S4968" /* Result may be `Mono<Void>`. */)
+    Mono<? extends @Nullable Void> after(Flux<T> flux) {
       return flux.then();
     }
   }
@@ -1127,12 +996,14 @@ final class ReactorRules {
   /** Avoid vacuous invocations of {@link Mono#ignoreElement()}. */
   static final class MonoThenEmpty<T> {
     @BeforeTemplate
-    Mono<@Nullable Void> before(Mono<T> mono, Publisher<@Nullable Void> publisher) {
+    @SuppressWarnings("java:S4968" /* Result may be `Mono<Void>`. */)
+    Mono<? extends @Nullable Void> before(Mono<T> mono, Publisher<@Nullable Void> publisher) {
       return mono.ignoreElement().thenEmpty(publisher);
     }
 
     @AfterTemplate
-    Mono<@Nullable Void> after(Mono<T> mono, Publisher<@Nullable Void> publisher) {
+    @SuppressWarnings("java:S4968" /* Result may be `Mono<Void>`. */)
+    Mono<? extends @Nullable Void> after(Mono<T> mono, Publisher<@Nullable Void> publisher) {
       return mono.thenEmpty(publisher);
     }
   }
@@ -1140,12 +1011,14 @@ final class ReactorRules {
   /** Avoid vacuous invocations of {@link Flux#ignoreElements()}. */
   static final class FluxThenEmpty<T> {
     @BeforeTemplate
-    Mono<@Nullable Void> before(Flux<T> flux, Publisher<@Nullable Void> publisher) {
+    @SuppressWarnings("java:S4968" /* Result may be `Mono<Void>`. */)
+    Mono<? extends @Nullable Void> before(Flux<T> flux, Publisher<@Nullable Void> publisher) {
       return flux.ignoreElements().thenEmpty(publisher);
     }
 
     @AfterTemplate
-    Mono<@Nullable Void> after(Flux<T> flux, Publisher<@Nullable Void> publisher) {
+    @SuppressWarnings("java:S4968" /* Result may be `Mono<Void>`. */)
+    Mono<? extends @Nullable Void> after(Flux<T> flux, Publisher<@Nullable Void> publisher) {
       return flux.thenEmpty(publisher);
     }
   }
@@ -1201,7 +1074,8 @@ final class ReactorRules {
     }
 
     @BeforeTemplate
-    Mono<@Nullable Void> before2(Mono<T> mono1, Mono<@Nullable Void> mono2) {
+    @SuppressWarnings("java:S4968" /* Result may be `Mono<Void>`. */)
+    Mono<? extends @Nullable Void> before2(Mono<T> mono1, Mono<@Nullable Void> mono2) {
       return mono1.thenEmpty(mono2);
     }
 
@@ -1219,7 +1093,8 @@ final class ReactorRules {
     }
 
     @BeforeTemplate
-    Mono<@Nullable Void> before2(Flux<T> flux, Mono<@Nullable Void> mono) {
+    @SuppressWarnings("java:S4968" /* Result may be `Mono<Void>`. */)
+    Mono<? extends @Nullable Void> before2(Flux<T> flux, Mono<@Nullable Void> mono) {
       return flux.thenEmpty(mono);
     }
 

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/RxJava2AdapterRules.java

@@ -23,14 +23,16 @@ final class RxJava2AdapterRules {
   /** Use the fluent API style when using {@link RxJava2Adapter#completableToMono}. */
   static final class CompletableToMono {
     @BeforeTemplate
-    Mono<@Nullable Void> before(Completable completable) {
+    @SuppressWarnings("java:S4968" /* Result may be `Mono<Void>`. */)
+    Mono<? extends @Nullable Void> before(Completable completable) {
       return Refaster.anyOf(
           RxJava2Adapter.completableToMono(completable),
           completable.to(RxJava2Adapter::completableToMono));
     }
 
     @AfterTemplate
-    Mono<@Nullable Void> after(Completable completable) {
+    @SuppressWarnings("java:S4968" /* Result may be `Mono<Void>`. */)
+    Mono<? extends @Nullable Void> after(Completable completable) {
       return completable.as(RxJava2Adapter::completableToMono);
     }
   }

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

@@ -16,6 +16,8 @@ final class ExplicitArgumentEnumerationTest {
             "import com.google.common.collect.ImmutableList;",
             "import com.google.errorprone.CompilationTestHelper;",
             "import com.google.errorprone.bugpatterns.BugChecker;",
+            "import io.micrometer.core.instrument.Counter;",
+            "import io.micrometer.core.instrument.Tag;",
             "import org.jooq.impl.DSL;",
             "import reactor.core.publisher.Flux;",
             "import reactor.test.StepVerifier;",
@@ -32,6 +34,8 @@ final class ExplicitArgumentEnumerationTest {
             "",
             "    DSL.row(ImmutableList.of(1, 2));",
             "",
+            "    Counter.builder(\"foo\").tags(ImmutableList.of(Tag.of(\"bar\", \"baz\")));",
+            "",
             "    // BUG: Diagnostic contains:",
             "    unaryMethod(ImmutableList.of(1, 2));",
             "    unaryMethodWithLessVisibleOverload(ImmutableList.of(1, 2));",

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

@@ -67,10 +67,11 @@ final class AssertJEnumerableRulesTest implements RefasterRuleCollectionTestCase
         assertThat(ImmutableSet.of(4)).size().isBetween(5, 6));
   }
 
-  ImmutableSet<EnumerableAssert<?, Integer>> testEnumerableAssertHasSameSizeAs() {
+  ImmutableSet<EnumerableAssert<?, Character>> testEnumerableAssertHasSameSizeAs() {
     return ImmutableSet.of(
-        assertThat(ImmutableSet.of(1)).hasSize(Iterables.size(ImmutableSet.of(2))),
-        assertThat(ImmutableSet.of(3)).hasSize(ImmutableSet.of(4).size()),
-        assertThat(ImmutableSet.of(5)).hasSize(new Integer[0].length));
+        assertThat("foo").hasSize(Iterables.size(ImmutableSet.of(1))),
+        assertThat("bar").hasSize(ImmutableSet.of(2).size()),
+        assertThat("baz").hasSize(new Integer[0].length),
+        assertThat("qux").hasSize("quux".length()));
   }
 }

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

@@ -66,10 +66,11 @@ final class AssertJEnumerableRulesTest implements RefasterRuleCollectionTestCase
         assertThat(ImmutableSet.of(4)).hasSizeBetween(5, 6));
   }
 
-  ImmutableSet<EnumerableAssert<?, Integer>> testEnumerableAssertHasSameSizeAs() {
+  ImmutableSet<EnumerableAssert<?, Character>> testEnumerableAssertHasSameSizeAs() {
     return ImmutableSet.of(
-        assertThat(ImmutableSet.of(1)).hasSameSizeAs(ImmutableSet.of(2)),
-        assertThat(ImmutableSet.of(3)).hasSameSizeAs(ImmutableSet.of(4)),
-        assertThat(ImmutableSet.of(5)).hasSameSizeAs(new Integer[0]));
+        assertThat("foo").hasSameSizeAs(ImmutableSet.of(1)),
+        assertThat("bar").hasSameSizeAs(ImmutableSet.of(2)),
+        assertThat("baz").hasSameSizeAs(new Integer[0]),
+        assertThat("qux").hasSameSizeAs("quux"));
   }
 }

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

@@ -15,7 +15,6 @@ import com.google.common.collect.ImmutableCollection;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
-import java.io.ByteArrayInputStream;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -211,57 +210,6 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
     return Mono.just(1).flux().single();
   }
 
-  ImmutableSet<Mono<String>> testMonoUsing() {
-    return ImmutableSet.of(
-        Flux.using(() -> new ByteArrayInputStream(new byte[] {}), s -> Mono.just("foo")).single(),
-        Flux.using(() -> new ByteArrayInputStream(new byte[] {}), s -> Flux.just("bar")).single());
-  }
-
-  ImmutableSet<Mono<String>> testMonoUsingEager() {
-    return ImmutableSet.of(
-        Flux.using(() -> new ByteArrayInputStream(new byte[] {}), s -> Mono.just("foo"), false)
-            .single(),
-        Flux.using(() -> new ByteArrayInputStream(new byte[] {}), s -> Flux.just("bar"), false)
-            .single());
-  }
-
-  ImmutableSet<Mono<String>> testMonoUsing2() {
-    return ImmutableSet.of(
-        Flux.using(() -> "foo", foo -> Mono.just("bar"), foo -> {}).single(),
-        Flux.using(() -> "foo", foo -> Flux.just("bar"), foo -> {}).single());
-  }
-
-  ImmutableSet<Mono<String>> testMonoUsing2Eager() {
-    return ImmutableSet.of(
-        Flux.using(() -> "foo", foo -> Mono.just("bar"), foo -> {}, false).single(),
-        Flux.using(() -> "foo", foo -> Flux.just("bar"), foo -> {}, false).single());
-  }
-
-  ImmutableSet<Mono<String>> testMonoUsingWhen() {
-    return ImmutableSet.of(
-        Flux.usingWhen(Mono.just("foo"), foo -> Mono.just("bar"), foo -> Mono.just("baz")).single(),
-        Flux.usingWhen(Mono.just("foo"), foo -> Flux.just("bar"), foo -> Mono.just("baz"))
-            .single());
-  }
-
-  ImmutableSet<Mono<String>> testMonoUsingWhen2() {
-    return ImmutableSet.of(
-        Flux.usingWhen(
-                Mono.just("foo"),
-                foo -> Mono.just("bar"),
-                foo -> Mono.just("baz"),
-                (foo, e) -> Mono.just("qux"),
-                foo -> Mono.just("thud"))
-            .single(),
-        Flux.usingWhen(
-                Mono.just("foo"),
-                foo -> Flux.just("bar"),
-                foo -> Mono.just("baz"),
-                (foo, e) -> Mono.just("qux"),
-                foo -> Mono.just("thud"))
-            .single());
-  }
-
   ImmutableSet<Flux<Integer>> testFluxSwitchIfEmptyOfEmptyPublisher() {
     return ImmutableSet.of(
         Flux.just(1).switchIfEmpty(Mono.empty()), Flux.just(2).switchIfEmpty(Flux.empty()));

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

@@ -17,7 +17,6 @@ import com.google.common.collect.ImmutableCollection;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
-import java.io.ByteArrayInputStream;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -210,55 +209,6 @@ final class ReactorRulesTest implements RefasterRuleCollectionTestCase {
     return Mono.just(1).single();
   }
 
-  ImmutableSet<Mono<String>> testMonoUsing() {
-    return ImmutableSet.of(
-        Mono.using(() -> new ByteArrayInputStream(new byte[] {}), s -> Mono.just("foo")),
-        Flux.using(() -> new ByteArrayInputStream(new byte[] {}), s -> Flux.just("bar")).single());
-  }
-
-  ImmutableSet<Mono<String>> testMonoUsingEager() {
-    return ImmutableSet.of(
-        Mono.using(() -> new ByteArrayInputStream(new byte[] {}), s -> Mono.just("foo"), false),
-        Flux.using(() -> new ByteArrayInputStream(new byte[] {}), s -> Flux.just("bar"), false)
-            .single());
-  }
-
-  ImmutableSet<Mono<String>> testMonoUsing2() {
-    return ImmutableSet.of(
-        Mono.using(() -> "foo", foo -> Mono.just("bar"), foo -> {}),
-        Flux.using(() -> "foo", foo -> Flux.just("bar"), foo -> {}).single());
-  }
-
-  ImmutableSet<Mono<String>> testMonoUsing2Eager() {
-    return ImmutableSet.of(
-        Mono.using(() -> "foo", foo -> Mono.just("bar"), foo -> {}, false),
-        Flux.using(() -> "foo", foo -> Flux.just("bar"), foo -> {}, false).single());
-  }
-
-  ImmutableSet<Mono<String>> testMonoUsingWhen() {
-    return ImmutableSet.of(
-        Mono.usingWhen(Mono.just("foo"), foo -> Mono.just("bar"), foo -> Mono.just("baz")),
-        Flux.usingWhen(Mono.just("foo"), foo -> Flux.just("bar"), foo -> Mono.just("baz"))
-            .single());
-  }
-
-  ImmutableSet<Mono<String>> testMonoUsingWhen2() {
-    return ImmutableSet.of(
-        Mono.usingWhen(
-            Mono.just("foo"),
-            foo -> Mono.just("bar"),
-            foo -> Mono.just("baz"),
-            (foo, e) -> Mono.just("qux"),
-            foo -> Mono.just("thud")),
-        Flux.usingWhen(
-                Mono.just("foo"),
-                foo -> Flux.just("bar"),
-                foo -> Mono.just("baz"),
-                (foo, e) -> Mono.just("qux"),
-                foo -> Mono.just("thud"))
-            .single());
-  }
-
   ImmutableSet<Flux<Integer>> testFluxSwitchIfEmptyOfEmptyPublisher() {
     return ImmutableSet.of(Flux.just(1), Flux.just(2));
   }

error-prone-experimental/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.21.1-SNAPSHOT</version>
+        <version>0.22.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>error-prone-experimental</artifactId>

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

@@ -29,6 +29,7 @@ import com.sun.source.tree.ReturnTree;
 import com.sun.source.tree.Tree;
 import com.sun.source.tree.VariableTree;
 import com.sun.tools.javac.code.Symbol;
+import com.sun.tools.javac.code.Symbol.PackageSymbol;
 import com.sun.tools.javac.code.Type;
 import java.util.List;
 import java.util.Optional;
@@ -126,7 +127,7 @@ public final class MethodReferenceUsage extends BugChecker implements LambdaExpr
         return Optional.empty();
       }
 
-      Symbol sym = ASTHelpers.getSymbol(methodSelect);
+      Symbol sym = ASTHelpers.getSymbol(subTree);
       return ASTHelpers.isStatic(sym)
           ? constructFix(lambdaExpr, sym.owner, methodSelect)
           : constructFix(lambdaExpr, "this", methodSelect);
@@ -200,7 +201,8 @@ public final class MethodReferenceUsage extends BugChecker implements LambdaExpr
     Name sName = target.getSimpleName();
     Optional<SuggestedFix.Builder> fix = constructFix(lambdaExpr, sName, methodName);
 
-    if (!"java.lang".equals(ASTHelpers.enclosingPackage(target).toString())) {
+    PackageSymbol pkg = ASTHelpers.enclosingPackage(target);
+    if (pkg != null && !"java.lang".equals(pkg.toString())) {
       Name fqName = target.getQualifiedName();
       if (!sName.equals(fqName)) {
         return fix.map(b -> b.addImport(fqName.toString()));

error-prone-guidelines/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.21.1-SNAPSHOT</version>
+        <version>0.22.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>error-prone-guidelines</artifactId>

error-prone-utils/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.21.1-SNAPSHOT</version>
+        <version>0.22.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>error-prone-utils</artifactId>

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

@@ -1,5 +1,7 @@
 package tech.picnic.errorprone.utils;
 
+import static java.util.Objects.requireNonNull;
+
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.ImmutableSet;
@@ -115,9 +117,15 @@ public final class AnnotationAttributeMatcher implements Serializable {
   }
 
   private static String extractAttributeName(ExpressionTree expr) {
-    return (expr instanceof AssignmentTree assignment)
-        ? ASTHelpers.getSymbol(assignment.getVariable()).getSimpleName().toString()
-        : "value";
+    if (!(expr instanceof AssignmentTree assignment)) {
+      return "value";
+    }
+
+    return requireNonNull(
+            ASTHelpers.getSymbol(assignment.getVariable()),
+            "Missing symbol for annotation attribute")
+        .getSimpleName()
+        .toString();
   }
 
   // XXX: The caller of this method can be implemented more efficiently in case of a "wholeTypes"

integration-tests/metrics-init.patch

@@ -38,7 +38,7 @@
 +            <dependency>
 +                <groupId>com.google.guava</groupId>
 +                <artifactId>guava</artifactId>
-+                <version>33.4.0-jre<!-- Renovate: com.google.guava:guava-bom --></version>
++                <version>33.4.7-jre<!-- Renovate: com.google.guava:guava-bom --></version>
 +            </dependency>
 +        </dependencies>
 +    </dependencyManagement>

pom.xml

@@ -4,7 +4,7 @@
 
     <groupId>tech.picnic.error-prone-support</groupId>
     <artifactId>error-prone-support</artifactId>
-    <version>0.21.1-SNAPSHOT</version>
+    <version>0.22.1-SNAPSHOT</version>
     <packaging>pom</packaging>
 
     <name>Picnic :: Error Prone Support</name>
@@ -146,7 +146,7 @@
         <error-prone.self-check-args />
         <!-- The build timestamp is derived from the most recent commit
         timestamp in support of reproducible builds. -->
-        <project.build.outputTimestamp>2025-03-24T10:41:07Z</project.build.outputTimestamp>
+        <project.build.outputTimestamp>2025-04-14T09:36:15Z</project.build.outputTimestamp>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <!-- Glob pattern identifying Refaster rule definition files. These
         Java classes don't contain "regular" code, and thus require special
@@ -211,11 +211,11 @@
         <version.guava-beta-checker>1.0</version.guava-beta-checker>
         <version.jdk>17</version.jdk>
         <version.maven>3.9.9</version.maven>
-        <version.mockito>5.16.1</version.mockito>
+        <version.mockito>5.17.0</version.mockito>
         <version.nopen-checker>1.0.1</version.nopen-checker>
-        <version.nullaway>0.12.4</version.nullaway>
-        <version.pitest-git>2.2.0</version.pitest-git>
-        <version.rewrite-templating>1.24.1</version.rewrite-templating>
+        <version.nullaway>0.12.6</version.nullaway>
+        <version.pitest-git>2.2.1</version.pitest-git>
+        <version.rewrite-templating>1.25.1</version.rewrite-templating>
         <version.surefire>3.2.3</version.surefire>
     </properties>
 
@@ -303,6 +303,16 @@
                 <artifactId>auto-value-annotations</artifactId>
                 <version>${version.auto-value}</version>
             </dependency>
+            <!-- XXX: JSR-305 (meta-)annotation usage by some dependencies
+            triggers NullAway to attempt to load said annotations. As such
+            some modules require these annotations to be on the classpath.
+            Periodically review whether we can drop this dependeny version
+            declaration. See https://github.com/uber/NullAway/issues/1171. -->
+            <dependency>
+                <groupId>com.google.code.findbugs</groupId>
+                <artifactId>jsr305</artifactId>
+                <version>3.0.2</version>
+            </dependency>
             <dependency>
                 <groupId>com.google.errorprone</groupId>
                 <artifactId>error_prone_annotation</artifactId>
@@ -331,7 +341,7 @@
             <dependency>
                 <groupId>com.google.googlejavaformat</groupId>
                 <artifactId>google-java-format</artifactId>
-                <version>1.25.2</version>
+                <version>1.26.0</version>
             </dependency>
             <dependency>
                 <groupId>com.google.guava</groupId>
@@ -341,7 +351,7 @@
             <dependency>
                 <groupId>com.google.guava</groupId>
                 <artifactId>guava-bom</artifactId>
-                <version>33.4.0-jre</version>
+                <version>33.4.7-jre</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
@@ -363,14 +373,14 @@
             <dependency>
                 <groupId>io.micrometer</groupId>
                 <artifactId>micrometer-bom</artifactId>
-                <version>1.14.5</version>
+                <version>1.14.6</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
             <dependency>
                 <groupId>io.projectreactor</groupId>
                 <artifactId>reactor-bom</artifactId>
-                <version>2024.0.4</version>
+                <version>2024.0.5</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
@@ -387,7 +397,7 @@
             <dependency>
                 <groupId>io.swagger.core.v3</groupId>
                 <artifactId>swagger-annotations</artifactId>
-                <version>2.2.29</version>
+                <version>2.2.30</version>
             </dependency>
             <dependency>
                 <groupId>jakarta.servlet</groupId>
@@ -422,7 +432,7 @@
             <dependency>
                 <groupId>net.bytebuddy</groupId>
                 <artifactId>byte-buddy</artifactId>
-                <version>1.17.4</version>
+                <version>1.17.5</version>
             </dependency>
             <!-- Specified so that Renovate will file Maven upgrade PRs, which
             subsequently will cause `maven-enforcer-plugin` to require that
@@ -435,7 +445,7 @@
             <dependency>
                 <groupId>org.aspectj</groupId>
                 <artifactId>aspectjweaver</artifactId>
-                <version>1.9.23</version>
+                <version>1.9.24</version>
             </dependency>
             <dependency>
                 <groupId>org.assertj</groupId>
@@ -447,7 +457,7 @@
             <dependency>
                 <groupId>org.checkerframework</groupId>
                 <artifactId>checker-qual</artifactId>
-                <version>3.49.1</version>
+                <version>3.49.2</version>
             </dependency>
             <dependency>
                 <groupId>org.hamcrest</groupId>
@@ -472,7 +482,7 @@
             <dependency>
                 <groupId>org.junit</groupId>
                 <artifactId>junit-bom</artifactId>
-                <version>5.12.1</version>
+                <version>5.12.2</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
@@ -498,7 +508,7 @@
             <dependency>
                 <groupId>org.openrewrite.recipe</groupId>
                 <artifactId>rewrite-recipe-bom</artifactId>
-                <version>3.4.0</version>
+                <version>3.6.1</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
@@ -610,7 +620,7 @@
                 <plugin>
                     <groupId>de.thetaphi</groupId>
                     <artifactId>forbiddenapis</artifactId>
-                    <version>3.8</version>
+                    <version>3.9</version>
                     <configuration>
                         <bundledSignatures>
                             <bundledSignature>jdk-internal</bundledSignature>
@@ -925,7 +935,7 @@
                         <dependency>
                             <groupId>com.puppycrawl.tools</groupId>
                             <artifactId>checkstyle</artifactId>
-                            <version>10.21.4</version>
+                            <version>10.23.0</version>
                         </dependency>
                         <dependency>
                             <groupId>io.spring.nohttp</groupId>
@@ -1136,7 +1146,7 @@
                         <dependency>
                             <groupId>org.codehaus.mojo</groupId>
                             <artifactId>extra-enforcer-rules</artifactId>
-                            <version>1.9.0</version>
+                            <version>1.10.0</version>
                         </dependency>
                     </dependencies>
                     <executions>
@@ -1300,7 +1310,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-surefire-plugin</artifactId>
-                    <version>3.5.2</version>
+                    <version>3.5.3</version>
                     <configuration>
                         <includes>
                             <include>**/*Test.java</include>
@@ -1497,7 +1507,7 @@
                 <plugin>
                     <groupId>org.jacoco</groupId>
                     <artifactId>jacoco-maven-plugin</artifactId>
-                    <version>0.8.12</version>
+                    <version>0.8.13</version>
                     <configuration>
                         <excludes>
                             <!-- Refaster rules are tested using a custom method
@@ -1527,7 +1537,7 @@
                 <plugin>
                     <groupId>org.pitest</groupId>
                     <artifactId>pitest-maven</artifactId>
-                    <version>1.19.0</version>
+                    <version>1.19.1</version>
                     <configuration>
                         <excludedClasses>
                             <!-- AutoValue generated classes. -->
@@ -1581,7 +1591,7 @@
                 <plugin>
                     <groupId>org.sonarsource.scanner.maven</groupId>
                     <artifactId>sonar-maven-plugin</artifactId>
-                    <version>5.0.0.4389</version>
+                    <version>5.1.0.4751</version>
                 </plugin>
             </plugins>
         </pluginManagement>
@@ -1940,6 +1950,7 @@
                                     -XepOpt:NullAway:AnnotatedPackages=tech.picnic
                                     -XepOpt:NullAway:AssertsEnabled=true
                                     -XepOpt:NullAway:CheckOptionalEmptiness=true
+                                    -XepOpt:NullAway:JSpecifyMode=true
                                     -XepOpt:Nullness:Conservative=false
                                     -XepOpt:StatementSwitchToExpressionSwitch:EnableDirectConversion=true
                                     <!-- Append additional custom arguments. -->

refaster-compiler/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.21.1-SNAPSHOT</version>
+        <version>0.22.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>refaster-compiler</artifactId>

refaster-runner/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.21.1-SNAPSHOT</version>
+        <version>0.22.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>refaster-runner</artifactId>

refaster-support/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.21.1-SNAPSHOT</version>
+        <version>0.22.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>refaster-support</artifactId>

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

@@ -1,38 +0,0 @@
-package tech.picnic.errorprone.refaster.matchers;
-
-import static com.google.errorprone.matchers.Matchers.isSameType;
-
-import com.google.errorprone.VisitorState;
-import com.google.errorprone.matchers.Matcher;
-import com.google.errorprone.suppliers.Suppliers;
-import com.sun.source.tree.ExpressionTree;
-import com.sun.source.tree.LambdaExpressionTree;
-import com.sun.source.tree.Tree;
-import com.sun.source.tree.Tree.Kind;
-import java.util.function.Function;
-
-/**
- * A matcher of lambda expressions that are of type {@code java.util.function.Function} that returns
- * a {@code reactor.core.publisher.Mono}.
- */
-public final class IsFunctionReturningMono implements Matcher<ExpressionTree> {
-  private static final long serialVersionUID = 1L;
-  private static final Matcher<Tree> MONO_TYPE =
-      isSameType(Suppliers.typeFromString("reactor.core.publisher.Mono"));
-  private static final Matcher<Tree> FUNCTION_TYPE =
-      isSameType(Suppliers.typeFromString(Function.class.getCanonicalName()));
-
-  /** Instantiates a new {@link IsFunctionReturningMono} instance. */
-  public IsFunctionReturningMono() {}
-
-  @Override
-  public boolean matches(ExpressionTree tree, VisitorState state) {
-    if (tree.getKind() != Kind.LAMBDA_EXPRESSION) {
-      return false;
-    }
-
-    LambdaExpressionTree lambdaExpressionTree = (LambdaExpressionTree) tree;
-    return MONO_TYPE.matches(lambdaExpressionTree.getBody(), state)
-        && FUNCTION_TYPE.matches(lambdaExpressionTree, state);
-  }
-}

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

@@ -1,44 +0,0 @@
-package tech.picnic.errorprone.refaster.matchers;
-
-import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
-
-import com.google.errorprone.BugPattern;
-import com.google.errorprone.CompilationTestHelper;
-import com.google.errorprone.bugpatterns.BugChecker;
-import org.junit.jupiter.api.Test;
-
-final class IsFunctionReturningMonoTest {
-  @Test
-  void matches() {
-    CompilationTestHelper.newInstance(MatcherTestChecker.class, getClass())
-        .addSourceLines(
-            "A.java",
-            "import java.util.function.Function;",
-            "import java.util.function.Supplier;",
-            "import reactor.core.publisher.Flux;",
-            "import reactor.core.publisher.Mono;",
-            "",
-            "class A {",
-            "  // BUG: Diagnostic contains:",
-            "  Function<String, Mono<String>> positive = s -> Mono.just(s);",
-            "",
-            "  Function<String, Flux<String>> negative = s -> Flux.just(s);",
-            "",
-            "  Supplier<Mono<String>> negative2 = () -> Mono.just(\"s\");",
-            "}")
-        .doTest();
-  }
-
-  /** A {@link BugChecker} that simply delegates to {@link IsFunctionReturningMono}. */
-  @BugPattern(summary = "Flags expressions matched by `IsFunctionReturningMono`", severity = ERROR)
-  public static final class MatcherTestChecker extends AbstractMatcherTestChecker {
-    private static final long serialVersionUID = 1L;
-
-    // XXX: This is a false positive reported by Checkstyle. See
-    // https://github.com/checkstyle/checkstyle/issues/10161#issuecomment-1242732120.
-    @SuppressWarnings("RedundantModifier")
-    public MatcherTestChecker() {
-      super(new IsFunctionReturningMono());
-    }
-  }
-}

refaster-test-support/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>tech.picnic.error-prone-support</groupId>
         <artifactId>error-prone-support</artifactId>
-        <version>0.21.1-SNAPSHOT</version>
+        <version>0.22.1-SNAPSHOT</version>
     </parent>
 
     <artifactId>refaster-test-support</artifactId>

website/_data/compatibility.yml

@@ -1,6 +1,9 @@
 # An overview of Error Prone Support releases, along with compatible Error
 # Prone releases. This data was generated by `generate-version-compatibility-overview.sh`.
 releases:
+  - version: 0.22.0
+    compatible:
+      - "2.37.0"
   - version: 0.21.0
     compatible:
       - "2.37.0"