Upstream V3.5.0 introduced a useRef<HTMLDivElement>() call with no
initial value. TS6 (and the tsgo preview compiler) now require an
explicit initial value for useRef typed against a DOM element. Pass
null to match the React 19 RefObject<HTMLDivElement | null> shape.
React 19 dropped the no-arg useRef overload — the type-only useRef<T>()
form (no initial value) is gone, every call must pass an initial value.
The codebase had 15 occurrences of useRef<HTMLDivElement>() (DOM ref
pattern) all flagged by tsgo as 'Expected 1 arguments, but got 0'.
Mechanical sweep to useRef<HTMLDivElement>(null) — no behavior change,
React still hands out a ref object with .current set to null at mount.
Net tsgo error count: 57 -> 42.
Run eslint --fix across src/ to clear ~1900 mechanical lint errors
surfaced by the @typescript-eslint v8 + react-hooks v7 + react-compiler
upgrade in the React 19 modernization PR.
Issues fixed automatically:
- brace-style (Allman): try/catch one-liners reformatted to multi-line
- indent: tab-vs-space and depth corrections
- semi: missing trailing semicolons
- no-trailing-spaces
No semantic changes. Remaining 701 errors are real-code issues
(set-state-in-effect, rules-of-hooks, no-unsafe-* type checks) that
need manual per-file review.
https://claude.ai/code/session_01GrR87LAqnAEyKG2ZbmQt5Q