Conversation
…already on left side
The recipe was failing to remove redundant null checks in patterns like:
if (s != null && "test".equals(s)) {}
The issue was that visitMethodInvocation would return early before calling
maybeHandleParentBinary when the select was already a literal. This prevented
the null check removal logic from running.
Additionally, maybeHandleParentBinary only checked if the null check matched
the select of the method invocation, but not the argument. For cases where the
literal is already on the left side (select), we need to check if the null
check matches the argument.
Changes:
- Moved maybeHandleParentBinary call before early returns to ensure null check
removal is always attempted for string comparison methods
- Extended null check matching to check both select and argument expressions
- Added comment clarifying that null check removal runs independently of
argument swapping logic
Fixes: org.openrewrite.staticanalysis.EqualsAvoidsNullTest#removeUnnecessaryNullCheckByItself
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
greg-at-moderne
approved these changes
Oct 20, 2025
mergify bot
added a commit
to robfrank/linklift
that referenced
this pull request
Oct 30, 2025
… 2.19.0 to 2.20.0 [skip ci] Bumps [org.openrewrite.recipe:rewrite-static-analysis](https://github.com/openrewrite/rewrite-static-analysis) from 2.19.0 to 2.20.0. Release notes *Sourced from [org.openrewrite.recipe:rewrite-static-analysis's releases](https://github.com/openrewrite/rewrite-static-analysis/releases).* > 2.20.0 > ------ > > What's Changed > -------------- > > * Avoid incorrect changes to Kotlin in RemoveUnusedLocalVariables by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#755](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/755) > * Fix EqualsAvoidsNull to remove redundant null checks when literal is already on left side by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#756](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/756) > * OpenRewrite recipe best practices by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#758](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/758) > * Fix RemoveUnusedPrivateFields for Lombok annotations after visibility modifiers by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-static-analysis#759](https://redirect.github.com/openrewrite/rewrite-static-analysis/pull/759) > > **Full Changelog**: <openrewrite/rewrite-static-analysis@v2.19.0...v2.20.0> Commits * [`241a923`](openrewrite/rewrite-static-analysis@241a923) Fix RemoveUnusedPrivateFields for Lombok annotations after visibility modifie... * [`ce75f31`](openrewrite/rewrite-static-analysis@ce75f31) OpenRewrite recipe best practices ([#758](https://redirect.github.com/openrewrite/rewrite-static-analysis/issues/758)) * [`b6d6d94`](openrewrite/rewrite-static-analysis@b6d6d94) Fix EqualsAvoidsNull to remove redundant null checks when literal is already ... * [`4c8fa35`](openrewrite/rewrite-static-analysis@4c8fa35) Drop rarely used `fromRuntimeClasspath` for `recipeFromResources` * [`a84f525`](openrewrite/rewrite-static-analysis@a84f525) Add second test class following commit comment * [`c195a4f`](openrewrite/rewrite-static-analysis@c195a4f) Never finalize super classes; Fixes [#372](https://redirect.github.com/openrewrite/rewrite-static-analysis/issues/372) * [`b92d93a`](openrewrite/rewrite-static-analysis@b92d93a) Avoid incorrect changes to Kotlin in RemoveUnusedLocalVariables ([#755](https://redirect.github.com/openrewrite/rewrite-static-analysis/issues/755)) * See full diff in [compare view](openrewrite/rewrite-static-analysis@v2.19.0...v2.20.0) [](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 merge` will merge this PR after your CI passes on it - `@dependabot squash and merge` will squash and merge this PR after your CI passes on it - `@dependabot cancel merge` will cancel a previously requested merge and block automerging - `@dependabot reopen` will reopen this PR if it is closed - `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually - `@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
2 participants
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
EqualsAvoidsNullrecipe to properly remove redundant null checks when the literal is already on the left side of the equals callEqualsAvoidsNullTest#removeUnnecessaryNullCheckByItselfProblem
The recipe was failing to remove redundant null checks in patterns like:
This should be simplified to:
However, the recipe was not making this transformation.
Root Cause
The issue had two parts:
Early return prevented null check removal: The
visitMethodInvocationmethod would return early whenhasCompatibleArgument(m)was false or when the select was already a literal. This preventedmaybeHandleParentBinary(the method responsible for removing redundant null checks) from being called.Incomplete null check matching: The
maybeHandleParentBinarymethod only checked if the null check matched the select of the method invocation (e.g.,sins.equals("test")), but didn't check if it matched the argument (e.g.,sin"test".equals(s)).Changes
maybeHandleParentBinarycall before the early return checks to ensure null check removal is always attempted for string comparison methodsmaybeHandleParentBinaryto check both the select and argument expressionsTest plan
EqualsAvoidsNullTest#removeUnnecessaryNullCheckByItselfnow passesEqualsAvoidsNullTestcontinue to pass🤖 Generated with Claude Code