2026: Better tsconfig breakdown

[sarahsporck]

Short description

One idea of yarn > 2 includes not hoisting dependencies. This means that e.g. jest/typescript/eslint is not hoisted to child dependencies. However we also don't want (and most of the time don't need) to install these dependencies in every workspace. Instead yarn berry allows to use global scripts, which can be accessible from anywhere. To ease the workflow with those global scripts it often helps alinging the configs to their framework specific monorepo setup.
For typescript this is described in the docs here.

Proposed changes

• Each tsconfig.json specifies exactly what files it includes
• Every reference (in a tsconfig file) will only be built if it has not yet been built before
  • This speeds up tsc --build command visibly

Side effects

• I had trouble with eslint running into oom in 2026: Update to yarn berry #2484. This is a known issue and can be fixed by removing enforceConsistentCasingInFilenames from the tsconfig and adding --max-old-space-size=1535 to the lint:ci command. If I see the builds failing for this PR I'll add this change.

Resolved issues

Relates: #2026

---

[steffenkleinle]

Tested, nice!

[LeandraH]

Very cool, and I can finally run yarn ts:check in the main directory 🥳