Disco

Disco is an original puzzle game inspired by Drop7. It currently retains some familiar foundations as an homage, but its rules and identity are intended to evolve independently.

The headless rules live under src/game/. Rendering and DOM UI live under src/ui/; audio, input, and cookie persistence live under src/platform/. These adapters are coordinated by src/app/game-controller.ts around the synchronous GameEngine turn result.

The browser game is a static Cloudflare Pages deploy. Its runtime has no client framework or bundled third-party game dependencies. Static UI markup lives beside its TypeScript behavior in src/ui/*.template.html; yarn build compiles src/, stitches those templates into public/index.html, and copies the styles into public/.

An optional account/statistics API lives under api/. It is a separate Fastify and SQLite Node service for VPS deployment, used for OIDC sign-in, cross-device stats sync, score submissions, and leaderboards. It has its own package, dependencies, tests, deployment notes, and lockfile so the API does not change the static Pages build surface. See api/README.md for API setup and VPS deployment details.

Run all headless tests:

yarn test

For local UI work, yarn dev performs an initial build, watches TypeScript and *.template.html files, and serves public/ on port 3000. Use yarn watch for the same build and watchers without starting the static server.

To run only the turn-level engine tests, use yarn run test:engine.

The engine accepts injected disc factories, so tests can use exact sequences instead of mocking Math.random():

const engine = new GameEngine({
  discFactory: () => makeDisc(7, DiscKind.Numbered),
  crackedDiscFactory: () => makeDisc(3, DiscKind.SingleCracked),
});

const result = engine.drop(2);

result.steps describes everything that occurred during the turn. The browser uses those steps for animation; tests can assert them directly.

The in-game logic debugger can export a JSON issue report. Schema version 4 includes turnHistory, containing the most recent turns in chronological order, plus truncatedTurns when older entries were omitted. Each turn still includes its physics steps, clear scans, and board frames. Built-in playable values are board-aware: taller stacks favor smaller values, with a secondary boost for values that could form an immediate horizontal or vertical match. Replaying generation requires the same generationSeed, starting board, and accepted move sequence, and it is only valid when generationSource === 'seeded'. Rejected moves do not advance generation. lastTurn remains available as a convenience for older analysis tools.