T-0GV4-md-engine-line-endings-corpus

State: closed/done · Impact: high · Complexity: small

Goal

state.doc.toString() joins lines with \n, so a CRLF note saves as LF: the editor violates the swap-writer rule of D-7VMX today. This task fixes emission with EditorState.lineSeparator and sliceDoc(), replaces the notes selection re-dispatch hack with requestRedraw, and lands the swap-writer corpus and the headless bench that every later engine task is measured against.

Today

Location	Role today
packages/ts/obsidian-editor/src/commands.ts#save	Emits state.doc.toString()
packages/ts/obsidian-editor/src/vue/index.ts#useObsidianEditor	Update listener and doc watcher compare and emit toString(); returns getOutline() (unused by consumers)
packages/ts/obsidian-editor/src/state.ts	Mode facet, compartment, setMode, scrollLineToTop; no line-separator or redraw plumbing
packages/ts/obsidian-editor/src/extensions.ts#obsidianEditorExtensions	No EditorState.lineSeparator
packages/ts/obsidian-editor/src/decorations.ts	Layers rebuild on docChanged, selectionSet, viewport change; nothing external can request a rebuild
solutions/determined/experiences/notes/app/components/NotesEditor.vue	redraw() re-dispatches the current selection to force a decoration rebuild after an asset or resolution lands
packages/ts/obsidian-editor/test/helpers.ts#makeState	Headless state builder the corpus test reuses
packages/ts/obsidian-md/test/fixtures/every-feature.md	Seed fixture for the corpus
packages/ts/obsidian-editor/moon.yml	test and typecheck tasks only

Proposed

The state module gains lineSeparatorFor(doc: string): '\n' | '\r\n' (CRLF when the first line break is CRLF, per D-4QGN item 4), redrawEffect: StateEffectType<null> and requestRedraw(view: EditorView): void. obsidianEditorExtensions installs EditorState.lineSeparator.of('\r\n') when the initial document is CRLF. Every emission — save, the Vue doc write-back, the Vue doc watcher — uses state.sliceDoc(). The inline plugin and the block field rebuild when a transaction carries redrawEffect.

useObsidianEditor returns outline: ShallowRef<OutlineEntry[]> (recomputed on doc change) instead of getOutline().

Swap-writer corpus under packages/ts/obsidian-editor/test/fixtures/corpus/: features.md (copied from the obsidian-md seed fixture), tables.md, math.md, details.md, crlf.md, whitespace.md (trailing spaces, tabs, no final newline), nested-callouts.md. packages/ts/obsidian-editor/test/swap-writer.test.ts asserts open → sliceDoc() identity for every fixture and, for every command in ALL_COMMANDS (a new export of the commands module: toggleBold, toggleItalic, insertLink today; T-EXQ7-md-engine-command-catalogue redefines it over the catalogue) at every line start and every inline node boundary of every fixture, that bytes outside the changed ranges are identical.

Bench under packages/ts/obsidian-editor/bench/: run.ts measures with performance.now() over the corpus plus a synthetic 10 000-line note — viewport decoration rebuild, keystroke transaction (insert one character, rebuild visible decorations), open-to-first-state — and writes baseline.json; compare.ts exits 1 when any measure exceeds 1.5× its baseline. A bench moon task runs the comparison.

Approach

1. Create the seven corpus fixtures; crlf.md is features.md re-encoded with \r\n.
2. Write the swap-writer test (identity and command matrix). The CRLF identity case fails before step 3 and passes after.
3. Add lineSeparatorFor, redrawEffect, requestRedraw to the state module; install the line separator in obsidianEditorExtensions.
4. Switch save and both Vue sync paths to sliceDoc(); replace getOutline() with the outline shallow ref; extend the Vue test (CRLF round trip, outline updates).
5. Make livePreviewPlugin and blockWidgetField rebuild on redrawEffect; add a test that a provider answer change followed by requestRedraw changes the decoration set.
6. Replace the selection re-dispatch in NotesEditor.vue with requestRedraw(view).
7. Write the bench runner and comparer, generate the baseline, add the bench moon task and bench / bench:baseline package scripts.

Files to touch

Location	Kind	Change
packages/ts/obsidian-editor/src/state.ts	modify	lineSeparatorFor, redrawEffect, requestRedraw
packages/ts/obsidian-editor/src/extensions.ts	modify	Install EditorState.lineSeparator for CRLF documents
packages/ts/obsidian-editor/src/commands.ts	modify	save emits sliceDoc(); export ALL_COMMANDS: StateCommand[]
packages/ts/obsidian-editor/src/decorations.ts	modify	Rebuild on redrawEffect
packages/ts/obsidian-editor/src/vue/index.ts	modify	sliceDoc() in both sync paths; outline shallow ref replaces getOutline
packages/ts/obsidian-editor/src/index.ts	modify	Export requestRedraw, redrawEffect, lineSeparatorFor
packages/ts/obsidian-editor/test/fixtures/corpus/features.md	new	Seed fixture copied from obsidian-md
packages/ts/obsidian-editor/test/fixtures/corpus/tables.md	new	GFM tables, alignment row, escaped pipes
packages/ts/obsidian-editor/test/fixtures/corpus/math.md	new	Inline and block math
packages/ts/obsidian-editor/test/fixtures/corpus/details.md	new	<details> blocks, nested and with <summary>
packages/ts/obsidian-editor/test/fixtures/corpus/crlf.md	new	CRLF line endings
packages/ts/obsidian-editor/test/fixtures/corpus/whitespace.md	new	Trailing spaces, tabs, no final newline
packages/ts/obsidian-editor/test/fixtures/corpus/nested-callouts.md	new	Callouts inside callouts and lists
packages/ts/obsidian-editor/test/swap-writer.test.ts	new	Identity and command matrix over the corpus
packages/ts/obsidian-editor/test/vue.test.ts	modify	CRLF round trip; outline ref
packages/ts/obsidian-editor/bench/run.ts	new	Timings over corpus and synthetic 10k-line note; writes the baseline
packages/ts/obsidian-editor/bench/compare.ts	new	Fails at more than 1.5× baseline
packages/ts/obsidian-editor/bench/baseline.json	new	Recorded baseline
packages/ts/obsidian-editor/moon.yml	modify	bench task
packages/ts/obsidian-editor/package.json	modify	bench and bench:baseline scripts
solutions/determined/experiences/notes/app/components/NotesEditor.vue	modify	redraw() calls requestRedraw(view)

Acceptance criteria

• AC-1: bun test packages/ts/obsidian-editor/test/swap-writer.test.ts passes, including the crlf.md identity case that fails before this task.
• AC-2: grep -rn "doc.toString()" packages/ts/obsidian-editor/src returns nothing.
• AC-3: for each of the seven corpus fixtures, each command in ALL_COMMANDS, and each position in the test’s position set, bytes outside the changed ranges are identical (the matrix in AC-1).
• AC-4: a test dispatches requestRedraw(view) after changing a stub provider’s resolveLink answer and the wikilink decoration class changes from cm-wikilink-missing to cm-wikilink-resolved.
• AC-5: grep -n "selection: current.state.selection" over solutions/determined/experiences/notes/app/components/NotesEditor.vue returns nothing.
• AC-6: useObsidianEditor returns outline and no getOutline; the Vue test asserts outline.value updates after a heading is inserted.
• AC-7: bun run bench:baseline in the package writes the baseline with entries rebuild-viewport-10k, keystroke-10k, and one open-<fixture> per corpus fixture; moon run obsidian-editor:bench exits 1 when a measure is forced to 2× its baseline.
• AC-8: the baseline records rebuild-viewport-10k below 8 ms and keystroke-10k p95 below 16 ms on the machine that generates it (the budgets in the program plan).

Out of scope

• Running the command matrix over the catalogue (T-EXQ7-md-engine-command-catalogue redefines ALL_COMMANDS over the catalogue; the test needs no change).
• Browser-side perf measurement (T-J92O-md-test-apps, T-I630-md-ui-playground-e2e-perf).
• Deleting NotesEditor.vue (T-3DFJ-notes-adopts-markdown-ui).

Dependencies

• T-4TE2-md-engine-plugin-contract so the redraw trigger lands in the dispatching builders.
• D-4QGN item 4 (line-ending preservation) and D-7VMX (swap writer) define the pass condition.

Discovery context

Member of milestone M-931L; engine step E2 of decision D-K3EM-markdown-editor-chrome-and-plugin-environment.

Depends on

T-4TE2-md-engine-plugin-contract

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