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Kotlin 2.4.0 ships with a HUGE power-assert update I've been slowly working on for *years*. It's the culmination of efforts I started before joining JetBrains. It's subtle from the user's perspective, but it helped fixed a bunch of problems and unblocks tons of future improvements! 🚀

kotlinlang.orgPower-assert compiler plugin | Kotlin

Kotlin by JetBrains@kotlinlang.org

📢 Kotlin 2.4.0 is out! Learn more: ➡️ kotl.in/2-4-0

Brian Norman

@bnorm.dev

5 years ago, while it was still a third-party compiler plugin, I realized power-assert needed a runtime library: github.com/bnorm/kotlin... 3 years ago I started experimenting with how that could work: github.com/bnorm/kotlin... Now power-assert is both first-party and has a runtime library! 🎉

4/6/26, 4:15 pm0 reposts0 likes

Brian Norman

@bnorm.dev

4 June

But why a runtime library? It fixed: array content in diagrams, multiline string handling, and excessive vertical space. It unblocks: diffs, local variables in diagrams, and non-assert use cases. And assertion libraries can support power-assert out-of-the-box, without custom Gradle config!

Brian Norman

@bnorm.dev

4 June

I talked about all of this recently at KotlinConf '26. The recording isn't available quite yet, but here are the slides. deck.bnorm.dev/kc26 And if you want to dive deep, there is a KEEP with all the technical details. github.com/Kotlin/KEEP/... The future is bright for power-assert!

deck.bnorm.devKotlinConf 2026