When Kotlin 2.x is supported?

[flex-gwanbin]

What problem are you trying to solve?

When running OpenRewrite on a project using Kotlin 2.x (K2 compiler), parsing fails with:

org.jetbrains.kotlin.utils.exceptions.KotlinIllegalArgumentExceptionWithAttachments:                                                                                                                                                   
  Unexpected FirClassLikeSymbol null for class ConeClassLikeLookupTagImpl

Current rewrite-kotlin uses kotlin-compiler-embeddable:1.9.25, which cannot parse Kotlin 2.x source code compiled with the K2 compiler.

Describe the solution you'd like

• Support for Kotlin 2.x projects. I see PR Use K2Compiler via JvmFirPipeline to support Kotlin v2 #6338 is already working on this.

Have you considered any alternatives or workarounds?

Excluding Kotlin files via exclusion("**/*.kt"), but this prevents recipes from being applied to Kotlin sources.

Additional context

• Project Kotlin version: 2.2.20
• OpenRewrite plugin version: 7.25.0
• Related PR: Use K2Compiler via JvmFirPipeline to support Kotlin v2 #6338 (Use K2Compiler via JvmFirPipeline to support Kotlin v2)

Are you interested in contributing this feature to OpenRewrite?

[flex-gwanbin]

Also, is there any plan to merge this PR which support K2? I really want to run SP4 migration recipe on Kotlin 2.2.20 repo, but still waiting 😢

[timtebeek]

Hi! We need to find time for a thorough review, especially given that we have a large exposed API surface when it comes to language support. If you're looking to help things along then build the PR that you've linked, try it out locally and report your findings there. :) I'll close this issue as we already had a tracking issue and PR.

• Support for Kotlin 2.2.0 Projects #6007