What JetBrains/kotlin shipped
Written by FoxPlug from public releases; not affiliated with Kotlin. An automatic summary of the public release, pull request and commit data of github.com/JetBrains/kotlin. Kotlin did not write it and does not use or endorse FoxPlug. Every line links to the public change it describes.
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Week of September 21, 2026
What shipped
- Added support for lombok.fieldDefaults.defaultPrivate in Java interop. Pull request #8437
- Context parameters are now supported in reflection APIs. Pull request #8320
- Removed deprecated IntrinsicRemember Compose feature flag. Pull request #8378
- JVM now generates bridges for @JvmFields when needed. Pull request #8341
- Fixed JVM inline processing to handle all type mappings before building fields for anonymous objects. Pull request #8429
- Added diagnostic for incorrect @EagerInitialization usage on non-top-level properties. Pull request #8386
- Implemented basic side-effect analysis and dead-code elimination in the JS backend. Pull request #6299
- TestReporter.publishEntry metadata is now preserved in KMP JVM reports. Pull request #8272
- Fixed ABI pollution in @JsPlainObject generated declarations. Pull request #8372
- Introduced PARSER_MODE three-state flag in the compiler. Pull request #8355
Why it matters
This week brings improvements to Java interop with Lombok support, reflection enhancements for context parameters, and important fixes across JS, JVM, and Wasm backends. Side-effect analysis for dead-code elimination in JS is a significant optimization feature. Several correctness fixes address annotation applicability and ABI compatibility issues.
Changelog entry
- Lombok: support lombok.fieldDefaults.defaultPrivate Pull request #8437
- Reflection: support context parameters Pull request #8320
- Removed deprecated IntrinsicRemember Compose feature flag Pull request #8378
- JVM: generate bridges for @JvmFields when needed Pull request #8341
- JVM/Inline: process all type mappings before building fields for anonymous objects Pull request #8429
- Fixed @EagerInitialization applicability with new diagnostic Pull request #8386
- JS: implement side-effect analysis and dead-code elimination Pull request #6299
- JS: fix ABI pollution in @JsPlainObject generated declarations Pull request #8372
- Gradle: preserve TestReporter.publishEntry metadata in KMP JVM reports Pull request #8272
- Fixed PackageDirectoryMismatch inspection misconfiguration Pull request #8388
- Serialization: copy type parameter bounds onto generated serializers Pull request #8163
This week: Lombok fieldDefaults support, context parameters in reflection, dead-code elimination for JS, @JvmFields bridges, IntrinsicRemember removal, and fixes for @EagerInitialization and @JsPlainObject.
Kotlin shipped several improvements this week: Lombok fieldDefaults.defaultPrivate support for better Java interop, context parameters now work with reflection, and a significant side-effect analysis feature enables dead-code elimination in the JS backend. Fixes include proper @JvmFields bridge generation, removal of deprecated IntrinsicRemember, validation of @EagerInitialization applicability, and ABI pollution fixes in @JsPlainObject.