Implement scribble game scenarios 1 to 4

[anirudhbs]

Summary

Full implementation of a multiplayer Scribble-style drawing and guessing game, built incrementally across four spec-driven scenarios on top of a minimal Express + React starter.

Scenarios

• Scenario 1 — Room Setup & Lobby: Host flag (isHost) on participants, name trimming + blank-name rejection (frontend inline errors + backend Zod), 404 on unknown room codes, 2-second setInterval polling in
  LobbyPage (with cleanup on unmount), host-only "Start Game" button disabled until ≥ 2 players.

• Scenario 2 — Game Start & Drawer Flow: POST /rooms/:code/start transitions room to "playing", assigns drawer (first participant by join order) and deterministic secret word (first entry in word list);
  drawer receives secretWord in the snapshot, all others do not; polling in LobbyPage navigates all clients to the Game screen on state change.

• Scenario 3 — Gameplay Interaction: DrawingCanvas upgraded from a static

  to a real with freehand mouse-event drawing and a "Clear" button; POST /rooms/:code/guess trims input, rejects empty
  with 400, compares case-insensitively to secret word, awards 100 / 0 points, appends to room.guesses; strokes and scores synced to all clients via existing 2-second poll.

• Scenario 4 — Result, Restart & Final Validation: POST /rooms/:code/end (host-only) transitions to "result"; POST /rooms/:code/restart (host-only) resets to "lobby", clearing
  secretWord/drawerName/guesses/scores/strokes while preserving participants; new ResultPage shows secret word, per-player scores, and full ordered guess history; polling in all three pages handles all state
  transitions.

Notable decisions

• Host identity via playerName — matched against participants[0].name rather than tokens/cookies; consistent with how guesses and strokes already identify the caller.
• "result" as a third RoomStatus value — minimal change to the existing union; all consumers already switch on status.
• Full result data always visible in "result" state — toRoomSnapshot exposes secretWord unconditionally once the round is over; no viewer filtering needed post-game.
• Scores reset on restart — spec explicitly scoped out cross-round accumulation; simpler data model.
• 2-second polling retained throughout — no WebSockets; acceptable latency for a local dev game and consistent with what was already in place.
• Full stroke replay from snapshot — canvas redraws all strokes from the poll snapshot on each tick; no incremental delta sync needed at this scale.

Contributor

• Email: anirudh.bs@everest.engineering
• Role:
  • Product
  • Developer