vscode-cowriting-plugin/sessions/0018/SESSION-0018.0-TRANSCRIPT-2026-06-11T07-03--2026-06-11T07-24.md

# Session 0018.0 — Transcript

> App: vscode-cowriting-plugin
> Start: 2026-06-11T07-03 (PST)
> End: 2026-06-11T07-24 (PST)
> Type: planning-and-executing
> Status: **FINALIZED**

## Launch prompt

> /goal Plan and execute Feature #17 (F6 diff-view toggle) from the graduated
> Solution Design at content specs/coauthoring-diff-view.md — 4 slices per §7.2,
> host-E2E tier, no LLM in CI

## Outcome

**F6 diff-view toggle (Feature #17) shipped to `main` via PR #18.** Planned and
executed in one session from the graduated Solution Design
`vscode-cowriting-plugin-content/specs/coauthoring-diff-view.md`, across its four
slices (§7.2). Issue #17 closed. Implementation plan archived to the content repo
`plans/`.

## Plan

Implementation plan: `docs/superpowers/plans/2026-06-11-f6-diff-view-toggle.md`
(written via `superpowers:writing-plans`, 9 tasks across the spec's 4 slices):

- **SLICE-1** Task 1 — `BaselineStore` (vscode-free) + vitest unit suite.
- **SLICE-2** Task 2 — additive `onDidApplyAgentEdit` seam event (INV-9/18);
  Task 3 — `DiffViewController` content provider + baseline lifecycle
  (ensure/advance/pin), storage-unavailable fallback.
- **SLICE-3** Task 4 — toggle UX via tab groups; Task 5 — wire into
  `extension.ts`; Task 6 — `package.json` commands + `ctrl+alt+d`.
- **SLICE-4** Task 7 — host E2E suite (no LLM, programmatic seam ingress);
  Task 8 — no-folder stub regression; Task 9 — manual smoke + README.

## Pre-state

- Branch `main`, clean, on `origin/main` (the claim's placeholder push for 0018
  was fast-forwarded in before work began).
- Epic #1 inner-loop ladder F2–F5 shipped (PRs #5/#7/#13/#15). F6 spec graduated
  in session 0017. No other sessions in flight (peek confirmed).

## Turn-by-turn arc

1. **Session gate + init.** Classified the opening `/goal` as
   planning-and-executing; ran `wgl-planning-and-executing`. Computed PST start
   `2026-06-11T07-03`, peeked (no in-flight), claimed session **0018** (atomic
   push). Verified clean pushed `main` baseline (synced the placeholder commit),
   confirmed the `@~/.claude/wiggleverse.md` stub present, resolved content +
   roadmap repos.
2. **Grounding.** Read the F6 spec end-to-end + the existing code it builds on:
   `store.ts` (CoauthorStore pattern), `attributionController.ts` seam
   (`applyAgentEdit` ~:232), `extension.ts` activation/`renderIfOpen`,
   `package.json` contributions, the E2E harness (`runTest.ts`, `suite/index.ts`,
   `proposals.test.ts`), `store.test.ts`, the no-workspace test, README tail.
3. **Plan.** Wrote the 9-task plan via `superpowers:writing-plans`; self-reviewed
   against the spec (full slice coverage, no placeholders, type consistency);
   cleaned a confusing `isDiffOpen` presentation in Task 4.
4. **Execution (inline, branch `f6-diff-view-toggle`, one commit per task):**
   - T1: `BaselineStore` + 5 vitest tests (TDD: red → green). 
   - T2: `onDidApplyAgentEdit` emitter, fired after a real seam apply. Typecheck +
     103 unit + 18+3 E2E stayed green (no listener yet).
   - T3: `DiffViewController` (provider + ensure/advance/pin + fallback + test
     surface), toggle stub.
   - T4: real toggle via tab groups (`vscode.diff`, findDiffTab, epochLabel,
     isDiffOpen).
   - T5: wired into `extension.ts` (store from `context.storageUri`, advance
     subscribed to the seam event, ensureBaseline in renderIfOpen, API field,
     no-folder stubs).
   - T6: `package.json` two commands + `ctrl+alt+d`.
   - T7: host E2E suite + fixture. First run **26 pass / 1 fail** — the
     "toggle closes → normal editor back" assertion introspected `activeTab`
     input type, transiently undefined right after `tabGroups.close`. Loosened it
     to assert `activeTextEditor` is the file (behavior-true). Re-run: **27 pass**.
   - T8: added the two F6 commands to the no-workspace stub regression. 27+3 green.
   - T9: `docs/MANUAL-SMOKE-F6.md` + README F6 section. Full gate: typecheck
     clean, 103 unit, 27+3 E2E (exit 0).
5. **Operator interjection (mid-T3):** "I saw errors in the bottom-right during
   those E2E tests." Investigated the run's exthost logs — **zero `[error]`
   lines**; only two benign built-in `[vscode.git]` config-access warnings (not
   ours, not toasts). Explained the corner toasts are the **expected** yellow
   warning-path assertions the suites deliberately trigger (stale-proposal,
   no-folder stubs, untracked); the only red `showErrorMessage` sites
   (`showClineSdkInfo`, live-turn `editSelection`) don't run in E2E.
6. **Ship.** Pushed branch, created **PR #18** via the Gitea API (mergeable),
   merged to `main`, synced local, deleted the branch. Commented + closed
   issue #17.
7. **Finalize.** Archived the plan to content `plans/` (commit 805fd80), updated
   memory, drafted the next `/goal`, published this transcript.

## Cut state

- `main` clean and synced; PR #18 merged; branch deleted.
- Issue #17 closed. Epic #1 (umbrella) remains open — only open issue.
- Plan archived: `vscode-cowriting-plugin-content/plans/2026-06-11-f6-diff-view-toggle.md`.
- Verification: typecheck clean · 103 unit · 27 + 3 host E2E (exit 0). No LLM in CI.
- **Not done (intentional):** live manual smoke (`docs/MANUAL-SMOKE-F6.md`) — an
  operator GUI gesture, not runnable in-session.

## Deferred decisions

_Autonomous-mode low-confidence calls surfaced at finalize._

- **From the spec (§9), carried into the plan as-specced:** absorb-on-advance
  semantics (vs. baseline splicing) and the `ctrl+alt+d` default keybinding —
  both decided in brainstorming (0017) without operator input. Both cheap to
  revisit; splicing is a documented additive follow-up.
- **This session:** loosened one E2E assertion ("toggle closes → normal editor
  back") from `activeTab` input-type introspection to `activeTextEditor` identity,
  because `activeTab` is transiently undefined right after `tabGroups.close`. The
  loosened form still proves the behavior (diff closed + file is the active
  editor). Low risk.

## Next-session prompt

```
/goal Capture the next vscode-cowriting-plugin feature(s) — F6 spec §9 deferred follow-ups (baseline splicing, named/selectable baselines, changed-line gutter indicators, cross-rung baseline sharing) — and/or assess closing Epic #1 now its F2–F6 ladder has shipped.
```

Read first: `memory/f6-diff-view-shipped.md`. There is **no `ROADMAP.md`** and no
open leaf issue — Epic #1 is the only open tracker item and its planned F2–F6
ladder is fully shipped, so the next move is genuinely a capture/triage decision,
not a queued build.