Kotlin 2.4.20 Released

Summary

Kotlin 2.4.20 is released with updates spanning the standard library, Kotlin/Native, Kotlin/Wasm, Kotlin/JS, Gradle, build tools, and the compiler. The standard library adds coroutine stack trace recovery, collection equality and uniqueness checks, and new kotlin.test assertion overloads. Kotlin/Native gains Swift export features, improved incremental compilation, and generated Package.swift files, while Kotlin/Wasm adds Wasmtime support in the Kotlin Gradle plugin and changes to require() handling in @JsFun declarations. Kotlin/JS introduces a browser-testing DSL, suspend-lambda exports as async functions, and improved data-class exportability. The release also supports Gradle 9.7.0, adds Build tools API targets, and provides the kotlinr runner command and a separate native image; it is available through updated IDEs, build scripts, or the command-line compiler.

Takeaways

1. 1

   Kotlin/Native adds new Swift export features, improved incremental compilation, and automatically generated Package.swift files for SwiftPM dependencies.

2. 2

   Kotlin/Wasm now supports Wasmtime in the Kotlin Gradle plugin, alongside changes to top-level require() calls in @JsFun declarations and companion object initialization order.

3. 3

   The Build tools API adds support for Kotlin/JS, Kotlin/Wasm, and Kotlin metadata targets, while the compiler introduces the kotlinr runner command and a separate native image.