perf(editor): stop blocking full-doc parse on note open#189
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The heading-fold foldService forced ensureSyntaxTree(doc.length, 5000ms) on every per-note editor remount, causing a ~1s stall on each note switch. Use the non-blocking syntaxTree(state) like the other live- preview extensions; the fold gutter only needs visible lines. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Root cause
Every note switch took ~1s. The editor is keyed per-note, so it fully remounts on each switch.
src/components/editor/foldableHeadings.tsresolved the syntax tree withensureSyntaxTree(state, state.doc.length, 5000), which forces a synchronous, blocking, full-document lezer parse (up to a 5s budget) at mount time — stalling the UI on each note open.Fix
One-line change in
resolveTree: use the non-blockingsyntaxTree(state)instead, matching every other live-preview extension in the codebase. The fold gutter only ever queries visible lines, so the forced full-doc parse was unnecessary. The now-unusedensureSyntaxTreeimport was removed (it had no other reference in the file).Checks
npm run lint— passnpm run typecheck— passnpm test -- --ci— 3017 passed / 17 skipped, all 9foldableHeadingstests green (they run on headless EditorState/EditorView and resolve fine viasyntaxTree)Build and Playwright e2e skipped.
Verify
The perf win should be confirmed by switching between notes on the Vercel preview — note open should no longer stall.
🤖 Generated with Claude Code