Fix ReplaceLambdaWithMethodReference for local records and classes

[timtebeek]

Summary

• Fixes ReplaceLambdaWithMethodReference breaks with local record definition #336

The ReplaceLambdaWithMethodReference recipe was generating malformed method references when converting lambdas that use locally-defined records or classes. Instead of producing valid syntax like R::s, it generated invalid code like 1R::s.

Root Cause: Local classes in Java bytecode are named with patterns like OuterClass$1LocalName, where the digit indicates the method scope. The recipe was including this numeric prefix in the generated method reference.

Changes:

• Modified JavaElementFactory.className() to detect local classes by checking for $<digit> patterns
• Extract only the simple class name without the numeric prefix for local classes
• Added comprehensive test coverage for local records and classes

Examples:

// Before (generates invalid code):
record R(String s) {}
stream.map(r -> r.s())  // would become: stream.map(1R::s) ❌

// After (generates valid code):
record R(String s) {}
stream.map(r -> r.s())  // becomes: stream.map(R::s) ✅

Test plan

• Added test localRecordMethodReference - verifies lambda to method reference conversion for local records
• Added test localClassMethodReference - verifies conversion for local classes
• Added test localRecordWithInstanceOfCheck - verifies instanceof to isInstance conversion
• Added test localRecordWithCast - verifies type cast to Class::cast conversion
• All existing tests pass (2m 5s test suite)

🤖 Generated with Claude Code