7.4 KiB
7.4 KiB
DECISIONS.md — blind_chess Decision Log
Project-specific decisions. For global/cross-cutting decisions, see ~/bin/DECISIONS.md.
Format: YYYY-MM-DD: <decision> — <why>
Architecture
- 2026-04-28: Node 22 + TypeScript stack — single-language top-to-bottom;
chess.jsis the de facto rules engine and lives natively here. - 2026-04-28: pnpm workspace with three packages —
packages/server(Fastify + ws),packages/client(Svelte + Vite),packages/shared(TS types). Shared types are the load-bearing decision: the WS protocol drift surface is high-risk and shared types catch it at compile time. - 2026-04-28: Fastify > Express — better TypeScript ergonomics, faster, cleaner plugin model for
wsintegration. - 2026-04-28: Svelte > React — smaller bundle, reactive stores fit the constantly-changing board state model. React is overkill for a 2-route app.
- 2026-04-28:
chess.jsfor rules + customgeometricMoveshelper — chess.js doesn't expose pseudo-legal moves; ~80 LoC pure function covers all six piece types. Lives inpackages/sharedso server and client use the same code. - 2026-04-28: In-memory only;
Map<gameId, Game>is the entire database — simplest possible. SQLite later if crash recovery becomes painful. Rejected: SQLite for MVP (premature given hobby-project scope). - 2026-04-28: Single-port Node service — Fastify serves both static client and
/wsupgrade on port 3000. No reverse proxy logic in our service; Caddy CT 600 handles TLS and routing. - 2026-04-28: Deploy target: new LXC on node-241 — clean isolation, matches existing patterns. Behind Caddy CT 600 at
chess.sethpc.xyz. - 2026-04-28: No auth beyond the hashed game link — friction-minimal; appropriate for casual play. No Authentik gate. Rejected: gating with Authentik (overkill).
- 2026-04-28: 8-character
gameId(32 bits,^[a-z0-9]{8}$), 24-characterPlayerToken(144 bits) — game IDs short enough for hand-shareable links, tokens long enough to prevent guessing. - 2026-04-28: WebSocket transport for in-game; REST POST
/api/gamesfor creation — keeps create flow simple (refresh-friendly, cacheable), keeps in-game traffic on a single channel.
Implementation
- 2026-04-28: Both modes (vanilla + blind) shipped day one — single engine, mode = per-player view filter. Vanilla mode is "blind mode with full reveal."
- 2026-04-28: Moderator hierarchy refined to four tiers: (1)
no_such_piece, (2)no_legal_moves= pseudo-legal ∅, (3)wont_help= pseudo-legal ≠∅ but legal ∅ (pin OR unresolved check), (4) silent = legal moves exist. Each tier is information-strictly-monotonic (more info revealed at later tiers). - 2026-04-28: Touch-move FSM — tap arms (reversible, client-side only), drag-start or destination-click commits ("touches"). Server tracks
armed: { color, from }.no_legal_movesandwont_helpchecks fire only on first commit with a piece; once committed, all subsequent failed attempts areillegal_movewith the touch staying. - 2026-04-28: Highlighting (blind+ON) is purely geometric — function of
(piece type, position, own-piece set), no opponent input. Rays extend through unseen opponent pieces. Stop at own pieces. Off-board excluded. Zero opponent info leak. (Vanilla+ON shows engine-truth: legal-empty as green dot, legal-capture as red ring.) - 2026-04-28: Game creation: creator picks side at create time (default random); single-use link (first joiner takes the open slot, then locked); no spectators in MVP; link dies with the game.
- 2026-04-28: Reconnect via opaque
PlayerTokenin browserlocalStorage, 5-minute grace window — generous for phone hiccups, short enough that abandoned games end. Grace expiry →endReason: 'abandoned', opponent wins. Both-sides simultaneous expiry → game ends withwinner: undefined. - 2026-04-28: Pawn promotion via modal (Q/R/B/N), client must include
promotionfield in the move; moderator announces the promotion (it's tactically significant — public info). - 2026-04-28: All draws auto-detected (stalemate, insufficient material, threefold, 50-move) — casual-play friendly; no "claim" UI.
- 2026-04-28:
Announcementis an enum (ModeratorText), not a free-form string. Display strings live client-side. Tests assert against enum values. - 2026-04-28:
updateis the single, idempotent server-to-client message that includes a filteredviewand any newAnnouncemententries. Replaying the latestupdateproduces correct render. - 2026-04-28: Moderator-vocabulary "errors" (no_such_piece, no_legal_moves, wont_help, illegal_move) come through as
Announcemententries onupdate, NOT aserrormessages. Errors reserved for protocol failures. - 2026-04-28: Janitor prunes finished games after 30 min idle; active games never expire (until restart).
- 2026-04-28: Rate limiting via per-token bucket on
commit: 10/s, burst 20 — well above human pace, well below abuse. - 2026-04-28: Mobile-first responsive design — IDEA.md's share-a-link flow strongly implies phone use.
- 2026-04-28: Logging via Pino (Fastify default) → journald.
/api/healthfor Uptime Kuma probe. No Prometheus/OpenTelemetry in MVP. - 2026-04-28: Resign + draw-offer/accept-decline flow — standard chess UX. Resignation ends without grace; disconnect applies grace.
- 2026-04-28: Game-over screen reveals full board for both sides — post-game review is part of the experience.
Deferred / Rejected
- 2026-04-28: Tactical-advice interpretation of "won't help you" — rejected. The phrase is a check-resolution announcement, not engine evaluation. Subjective "this move is bad" is anti-fun and out of scope.
- 2026-04-28: Spectator mode — deferred. Single-use links and no spectators in MVP. Revisit if there's demand.
- 2026-04-28: Time controls (clocks) — deferred. Untimed correspondence-style for MVP. Optional 5+0 / 10+0 / 15+10 in a follow-up if Seth wants.
- 2026-04-28: SQLite persistence — deferred. In-memory only for MVP. Add when crash recovery becomes painful (1-day implementation: serialize Map on
ExecStop, deserialize onExecStart). - 2026-04-28: End-to-end browser tests (Playwright) — out of scope for MVP. Protocol-level integration tests cover the same drift surface for ~10× less maintenance. Manual phone+desktop testing suffices.
- 2026-04-28: Vanilla-only or blind-only MVP — rejected in favor of both-from-day-one. The shared engine + view-filter architecture means vanilla is essentially free.
- 2026-04-28: Authentik gate on
chess.sethpc.xyz— rejected. The hashed link IS the auth; an additional gate would be friction with no security benefit (link guessing is already infeasible). - 2026-04-28: CI/CD automation — deferred. Manual
pnpm -r build+rsync+systemctl restartis fine for a hobby project. Add Gitea Actions later if deploy friction grows. - 2026-04-28: Move log / PGN export, post-game replay — deferred. Announcements are persisted in-game (so the moderator-panel scrollback works); export and replay are post-MVP.
- 2026-04-28: Public lobby / matchmaking / ratings — out of scope. This is a private-link game, not a chess site.
- 2026-04-28: Pre-deploy "server restarting" warning to active players — stretch goal, not MVP. Mitigation for now: deploy during low-usage windows.
- 2026-04-28: Client-side AI / hint generation — explicitly out of scope. Human vs. human only.