vscode-cowriting-plugin/sessions/0048/SESSION-0048.0-TRANSCRIPT-2026-06-13T08-45--2026-06-13T08-58.md

Session 0048.0 — Transcript

App: vscode-cowriting-plugin Start: 2026-06-13T08-45 (PST) Type: planning-and-executing End: 2026-06-13T08-58 (PST) Status: FINALIZED. Posture: autonomous (yolo)

Launch prompt

/goal plan-and-execute #40 (restore exact author attribution on undo/redo — follow-up to #38)

Plan

#40 (task, P3) — restore exact author attribution on undo/redo (follow-up to #38). Anchor: leaf task → §4.3 R2 (no design gate). Picked autonomously (last R2-eligible leaf not blocked by a content-repo/careful/irreversible gate).

#38 made undo/redo re-inserted text neutral (no false human coloring) but lossy: undoing a deletion of Claude text shows it neutral, not blue. #40 restores the exact prior attribution.

Mechanism (engineering choice): text-keyed attribution snapshots. Per-doc Map<documentText, spans>; snapshot after every FORWARD edit (and at load). On undo/redo, after the #38 geometry reconcile, if a snapshot's text equals the current buffer, restore those spans exactly (offsets valid — text identical). Robust to VS Code undo coalescing (only the event whose resulting text matches a snapshot restores; far-back/evicted states fall back to #38 neutral). Bounded history.

Tasks: snapshot+restore in attributionController (loadAll + onDidChange); tests (agent-text undo restores blue; edit→undo→redo round-trip; #38 regression green). No deploy pipeline (extension).

Results

#40 implemented but NOT shipped — verification-blocked. On branch s40-undo-provenance (pushed, unmerged); issue #40 kept open.

• attributionController.ts — text-keyed attribution snapshots (attrHistory: Map<documentText, spans>, ATTR_HISTORY_MAX bounded): snapshot after every forward edit + at loadAll; on undo/redo restore the snapshot whose text equals the current buffer (else #38 neutral fallback). Robust to undo coalescing.
• test/e2e/suite/s40Provenance.test.ts — agent-text-undo-restores-blue + edit→undo→redo round-trip.
• 222 unit + typecheck green.

BLOCKER (environmental, not the code): the #40 host E2E — and the untouched #38 undoMarks E2E — drive executeCommand("undo"), which does not restore text in this local test instance. Proven by stashing all my changes and running clean main: the #38 test fails identically (undo restored 'bravo'). This is the known undoMarks flake (session 0037), now deterministic in this environment. The usual remedy — clearing .vscode-test/user-data — is permission-blocked this session (rm -rf denied). Focusing the doc before undo (showTextDocument) did not help. So #40's end-to-end behavior cannot be verified here; shipping unverified changes to the load-bearing F3 attribution controller would violate verify-before-completion. Left on a branch for the operator to verify + merge in a working E2E environment.

Also surfaced: main's E2E is currently red in this environment for the same environmental reason (the undoMarks undo flake) — a test-infra issue independent of product code.

Session arc

1. Stop hook required determining/executing the next milestone; chose #40 (last R2-eligible leaf). Claimed 0048, clean main.
2. Read #40 + #38 + the attribution change handler; chose text-keyed snapshots.
3. TDD: wrote #40 E2E + implemented snapshot/restore; 222 unit green.
4. E2E: 3 undo-driven tests failed at the undo restored X step. Isolated by stashing → clean main's #38 test fails identically → environmental undo flake, not my code. Could not clear .vscode-test (permission-blocked).
5. Committed #40 to a branch (pushed, unmerged, marked UNVERIFIED); kept #40 open; stopped per verify-before-completion.

Deferred decisions

Autonomous-mode low-confidence calls the driver made and would have liked operator input on. Empty if none.

• Did not merge #40 (driver call). Alternative: merge on unit-green + reasoning alone. Why not: it changes the core F3 attribution controller and its behavior is only meaningfully provable through an undo E2E, which is environmentally broken here — verify-before-completion says don't claim/ship it. Preserved on a branch for operator verification instead. (Reversible: just merge once verified.)