SimplifyBooleanExpression: skip nullable boolean comparisons in Kotlin#7103
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jkschneider merged 1 commit intomainfrom Mar 23, 2026
Merged
SimplifyBooleanExpression: skip nullable boolean comparisons in Kotlin#7103jkschneider merged 1 commit intomainfrom
jkschneider merged 1 commit intomainfrom
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…s in Kotlin `shouldSimplifyEqualsOn` now checks whether the source file is Java before allowing `x == true` / `x != false` simplifications. For non-Java languages (Kotlin), simplification is restricted to primitive boolean types to avoid changing semantics of nullable Boolean comparisons like `Boolean? == true`. Fixes openrewrite/rewrite-static-analysis#303
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Summary
Fixes
shouldSimplifyEqualsOninSimplifyBooleanExpressionVisitorto not simplifyx == true/x != falsewhen the source is Kotlin andxcould be a nullableBoolean?In Kotlin,
nullableBoolean == trueevaluates tofalsewhen null (safe idiom), whereasnullableBooleandirectly is a type error — so the simplification changes semanticsUses the same pattern as
canSimplifyDoubleNegation: allow all simplifications for Java (J.CompilationUnit), restrict to primitive boolean for other languagesAdds Kotlin-specific tests covering nullable receiver, nullable variable,
== false, and!= truecasesFixes Kotlin code with nullable fields in data classes breaks
SimplifyBooleanExpressionrewrite-static-analysis#303Test plan
SimplifyBooleanExpressionVisitorTest)Boolean?comparisons are preserved!false,|| true,&& false) still simplify