Strip diamond operator from cast in UseLambdaForFunctionalInterface#893
Merged
Conversation
The diamond operator is only valid after `new` (JLS 15.9), not in a cast
expression (JLS 15.16). When converting `new Foo<>() {...}` to a lambda
that required a cast, the recipe produced invalid `(Foo<>) ...`.
Instead of stripping the diamond to a raw cast like `(Foo)`, reconstruct the parameterized type from the resolved interface's type arguments so the emitted cast (e.g. `(Foo<Bar>)`) compiles without unchecked warnings.
Add `hasDiamond` helper, use static-imported `emptyList()`, and flatten the diamond-handling block.
The earlier port handled `Primitive`, `GenericTypeVariable`, and wildcards, but those branches are unreachable here: generics can't be primitive, and the parser collapses type variables to their bound when inferring a diamond's type arguments. Reduce the helper to the only reachable path (`FullyQualified`) and add a multi-arg test.
mergify Bot
added a commit
to robfrank/linklift
that referenced
this pull request
Jun 4, 2026
… 2.34.0 to 2.36.0 [skip ci] Bumps [org.openrewrite.recipe:rewrite-static-analysis](https://github.com/openrewrite/rewrite-static-analysis) from 2.34.0 to 2.36.0. Release notes *Sourced from [org.openrewrite.recipe:rewrite-static-analysis's releases](https://github.com/openrewrite/rewrite-static-analysis/releases).* > 2.36.0 > ------ > > What's Changed > -------------- > > * Guard `instanceof` to `Class::isInstance` conversion on lambda arity by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#903](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/903) > * Preserve cast on argument to overloaded method in `RemoveRedundantTypeCast` by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#904](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/904) > * Preserve raw cast on parameterized expression in `RemoveRedundantTypeCast` by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#905](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/905) > * Skip Python sources in `CombineSemanticallyEqualCatchBlocks` by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#908](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/908) > * Use receiver type for unbound instance method reference in `ReplaceLambdaWithMethodReference` by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#909](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/909) > * Regenerate recipes.csv by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#910](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/910) > * Retain load-bearing type witness in select position in `UnnecessaryExplicitTypeArguments` by [`@knutwannheden`](https://github.com/knutwannheden) in [openrewrite/rewrite-static-analysis#911](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/911) > > **Full Changelog**: <openrewrite/rewrite-static-analysis@v2.35.0...v2.36.0> > > 2.35.0 > ------ > > What's Changed > -------------- > > * Document identity-semantics caveat on PrimitiveWrapperClassConstructorToValueOf by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#883](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/883) > * Skip `FinalClass` when class has anonymous inner subclasses by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#886](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/886) > * Skip `ReplaceLambdaWithMethodReference` for parameterized types with multiple constructors by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#887](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/887) > * Preserve `null` cast at varargs position in `RemoveRedundantTypeCast` by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#888](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/888) > * Retain explicit type arguments on no-arg static methods in `UnnecessaryExplicitTypeArguments` by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#889](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/889) > * Detect overloads on parameterized receiver in `hasMethodOverloading` by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#890](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/890) > * Preserve cast on generic method invocation in overloaded outer call by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#891](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/891) > * Guard cast to `JavaType.Annotation` in `ReorderAnnotations` by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#894](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/894) > * Strip diamond operator from cast in `UseLambdaForFunctionalInterface` by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#893](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/893) > * Replace `var` with interface type in `UseLambdaForFunctionalInterface` by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#896](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/896) > > **Full Changelog**: <openrewrite/rewrite-static-analysis@v2.34.1...v2.35.0> > > v2.34.1 > ------- > > What's Changed > -------------- > > * OpenRewrite [v8.81.6](https://github.com/openrewrite/rewrite/releases/tag/v8.81.6) > * Preserve statement order in `UseTryWithResources` by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#866](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/866) > * Skip meta-annotated `@Configuration` in `FinalClass` and `HideUtilityClassConstructor` by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#867](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/867) > * OpenRewrite recipe best practices by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#869](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/869) > * Revert to using rewrite-java-21 for test runtime by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#870](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/870) > * Preserve casts pinning generic-method return type in lambdas by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#872](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/872) > * Preserve `(Object)` bridge cast for unchecked generic casts by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#876](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/876) > * Skip `Objects::nonNull`/`isNull` when lambda parameter does not match by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#875](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/875) > * Regression tests for ReplaceStackWithDeque ControlFlow crashes by [`@knutwannheden`](https://github.com/knutwannheden) in [openrewrite/rewrite-static-analysis#879](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/879) > * Skip `SimplifyConsecutiveAssignments` when initializer would self-reference by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#882](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/882) > > **Full Changelog**: <openrewrite/rewrite-static-analysis@v2.34.0...v2.34.1> Commits * [`01d4a78`](openrewrite/rewrite-static-analysis@01d4a78) Update Gradle wrapper 9.5.1 * [`421318a`](openrewrite/rewrite-static-analysis@421318a) Retain load-bearing type witness in select position in `UnnecessaryExplicitTy... * [`c488082`](openrewrite/rewrite-static-analysis@c488082) Regenerate recipes.csv ([#910](https://redirect.github.com/openrewrite/rewrite-static-analysis/issues/910)) * [`829a5a5`](openrewrite/rewrite-static-analysis@829a5a5) Use receiver type for unbound instance method reference in `ReplaceLambdaWith... * [`5ab23a2`](openrewrite/rewrite-static-analysis@5ab23a2) Skip Python sources in `CombineSemanticallyEqualCatchBlocks` ([#908](https://redirect.github.com/openrewrite/rewrite-static-analysis/issues/908)) * [`e4bcb09`](openrewrite/rewrite-static-analysis@e4bcb09) Preserve raw cast on parameterized expression in `RemoveRedundantTypeCast` (#... * [`62e6a08`](openrewrite/rewrite-static-analysis@62e6a08) Preserve cast on argument to overloaded method in `RemoveRedundantTypeCast` (... * [`3ef523d`](openrewrite/rewrite-static-analysis@3ef523d) Guard `instanceof` to `Class::isInstance` conversion on lambda arity ([#903](https://redirect.github.com/openrewrite/rewrite-static-analysis/issues/903)) * [`03d153e`](openrewrite/rewrite-static-analysis@03d153e) Replace `var` with interface type in `UseLambdaForFunctionalInterface` ([#896](https://redirect.github.com/openrewrite/rewrite-static-analysis/issues/896)) * [`8e930b0`](openrewrite/rewrite-static-analysis@8e930b0) Strip diamond operator from cast in `UseLambdaForFunctionalInterface` ([#893](https://redirect.github.com/openrewrite/rewrite-static-analysis/issues/893)) * Additional commits viewable in [compare view](openrewrite/rewrite-static-analysis@v2.34.0...v2.36.0) [](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores) Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`. [//]: # (dependabot-automerge-start) [//]: # (dependabot-automerge-end) --- Dependabot commands and options You can trigger Dependabot actions by commenting on this PR: - `@dependabot rebase` will rebase this PR - `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it - `@dependabot show ignore conditions` will show all of the ignore conditions of the specified dependency - `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
new Foo<>() {...}) into a lambda that requires a cast, the recipe previously copied the sourceJ.ParameterizedTypeverbatim and emitted invalid(Foo<>) .... The diamond is only valid afternew(JLS 15.9), not in a cast (JLS 15.16), so this strips the empty type-parameter list and falls back to a raw-type cast.Test plan
diamondOperatorInAnonymousClasstest reproducing the bug withAccessController.doPrivileged(new PrivilegedAction<>() {...})and asserting the output is(PrivilegedAction) () -> 0./gradlew test --tests UseLambdaForFunctionalInterfaceTestpasses