# TASK 41 — Test Stream mode: private test broadcast + TEST drawer

**Status:** ✅ Done (2026-09-22) — one scope-checked work unit, one Good Dog integration test,
314/314 suite green, 0 warnings.

## Creator ask (2026-09-22)

"YouTube Test Stream & Chat Integration": a **Test/Preview** button beside Start that runs a
private broadcast via the API, monitors stream/ingest, activates the chat endpoint (liveChatId),
and provides a **chat simulator**: mock chat input (`liveChatMessages.insert`) + a toggle to
inject mock chat, with alert/event triggers for subscriber, membership, and Super Chat.

## Locked decisions (user answers, 2026-09-22)

- **Chat-overlay events only** — simulated events validate the existing chat overlay styling
  (text / member `memberColor` / SuperChat `superChatColor` rows). Dedicated stinger/TTS alert
  widgets are NOT part of this task — they stay queued under **TASK 3 items 16/17/20**.
- **TEST drawer in the right rail** — third white tab below YPP, three-way one-open-at-a-time
  exclusivity, auto-opens when a test broadcast boots.
- **Hybrid simulation** — text = REAL `liveChat/messages.insert` (round-trips the real 2s poll
  and renders through the live overlay path); member/SuperChat/subscriber = **local injection** at
  the poller's `MessageReceived` seam (marked `IsSimulated`). YouTube's insert API only creates
  `textMessageEvent`s — non-text events are local-only by design.

## Facts the build sits on (verified in code, 2026-09-22 research pass)

- **The app is already private-only go-live** — `YouTubeStreamService.CreateBroadcast` hardcodes
  `privacyStatus="private"` + `enableAutoStart/Stop` + `low latency`, no monitor stream
  (`enableMonitorStream=false`), and the Go Live dialog is locked to Private. "Test" is therefore a
  **session variant over the real pipeline**, not a new broadcast mode.
- The **liveChatId flow already exists**: `GetBroadcastLiveChatIdAsync` → `_youtubeChat.Start(liveChatId)`
  in `PrepareAndStartLiveAsync` — the "chat endpoint activation" the ask describes.
- OAuth scope already includes `youtube` + `youtube.force-ssl` (`YouTubeAuthService.cs:18`) —
  enough for `liveChat/messages.insert`; no re-consent.
- Chat = **polling** (`YouTubeChatService`, 2s): no webhook exists or is planned.
- No alert system exists anywhere in the codebase (grep verified) — hence the scope decision above.
- Existing mock-chat *preview* (`ChatOverlayLayer.StartMockChatPreview`) is static placeholders,
  not live-injectable — separate from this task.

## What shipped (TASK 41, 2026-09-22)

- **`Controls/TopBar.xaml`** — **Test** button (secondary style) left of Start; visible only when
  `ShowTestButton` (offline ∧ not recording ∧ signed-in); **TEST** amber badge while
  `IsTestStream` (next to the elapsed clock).
- **`Controls/PreviewPane.xaml`** — **TEST** tab (gold text, below YPP on the rail) + TEST drawer:
  session caption / liveChatId line, **Mock Chat Input** (TextBox + Send), **SIMULATED EVENTS**
  (Subscriber / New Member / Super Chat buttons), live feedback line, footer "End Test" + the
  "private, same pipeline as a real live" note; drawer exclusivity wired three-way.
- **`Services/TestSessionViewModel.cs`** (NEW) — the TEST drawer VM: `BeginTest(broadcastId,
  liveChatId)` (auto-opens the dock once the liveChatId resolves), `SendTestMessageAsync` → real
  insert, `Simulate{Subscriber,Member,SuperChat}Command` → `InjectSimulatedMessage`, `EndTestCommand`
  → hands to `MainViewModel.StopStream`, `EndTestSilently` (idempotent, called on any stop/
  rollback). Fully testable — takes `YouTubeStreamService` + `YouTubeChatService` via ctor.
- **`Services/YouTubeStreamService.InsertChatMessageAsync(liveChatId, text)`** —
  `POST liveChat/messages?part=snippet`; returns string error or null; never throws.
- **`Services/YouTubeChatService.InjectSimulatedMessage(ChatMessage)`** — raises `MessageReceived`,
  the exact seam the real poll uses, so simulations flow through the whole overlay pipeline;
  marked `ChatMessage.IsSimulated`.
- **`ViewModels/MainViewModel.*`** — `IsTestStream` (internal setter, test seam like `IsRecording`);
  `BeginTestStream()` → the shared `StartStreamingSession(alsoRecord:false)` extracted from
  `BeginGoLive` (no dialog — a Test needs no confirmation, every broadcast is already private; no
  `BroadcastForm.CaptureGoLive` "last live" stamp; no recording). `StopStream` clears the face and
  forgets the drawer session. `EndButtonText` = "End Test" while in a test. Gold top bar + glow
  (`#9c6f1c`) identify a rehearsal vs the live red.
- **Drawer exclusivity** (this task): opening TEST collapses Stream Settings + YPP and vice versa
  (wired in `MainViewModel.Ypp.cs`).

## Good Dog — ONE integration test

`ytLive.Tests/TestStreamTests.cs` — one `[Fact]`, two sections:
1. **Coordinator (no network, `RecordingHandler`-faked HTTP):** idle → `BeginTest` opens the dock
   + enables chat; Mock Chat Input emits the insert (POST body asserted for the liveChatId +
   messageText); Subscriber/New Member/Super Chat simulations arrive through `MessageReceived`
   marked `IsSimulated` with the right shapes (member level, `$5.00` Super Chat, plain subscriber
   row); End hands back to the app; `EndTestSilently` clears.
2. **Real window (temp DB):** TEST tab/drawer exist, three-way drawer exclusivity, Test button
   gate follows sign-in deterministically.

## Follow-ups (NOT in this task)

- Real stinger/TTS alert widgets → TASK 3 items 16/17/20.
- Test-mode health-panel depth (per-broadcast status inside the drawer) if ever wanted.