docs: document TypeScript 5.3 minimum supported version by sethamus · Pull Request #20547 · eslint/eslint (original) (raw)

The TypeScript 6 beta was announced on Feb 11, 2026 and includes a list of Breaking Changes and Deprecations.

Thanks for the heads‑up, @MikeMcC399. I tried installing typescript@beta6.0.0-beta, and I'm not seeing any differences in this repo compared to TypeScript 5.9.3. In the eslint/rewrite repo, after installing typescript@beta6.0.0-beta, both the build and the tests ran successfully with only minimal changes to the tsconfig (essentially just disabling strict mode by default and adding rootDir to the compiler options). So it looks like our current types will continue to work in TypeScript 6 without any modifications.

I suggest to consider the wording:

If you use ESLint's TypeScript type definitions, TypeScript 5.3 or later is required.

which would include TypeScript 6. If you want to exclude TypeScript 6 you could write something like:

If you use ESLint's TypeScript type definitions, TypeScript 5 (5.3 or later) is required.

TypeScript 6 could be added later, after it has been released and can be added to ESLint's CI tests.

Once TypeScript 6 is officially released, it would make sense to update our entire build tooling to use it, while still running tests on TypeScript 5.3 also. If users start reporting issues on ESLint because they run into errors when upgrading to TypeScript 6, we could also consider adding troubleshooting instructions. But if a bug only appears with TypeScript 6, I think it would be better to address it rather than saying that TypeScript 6 isn't supported yet. So I don't think we should proactively limit compatibility to TypeScript 5.