The offline vs_ai game engine — a faithful TS port of backend/internal/engine that
drives a whole local game with no backend. Composes with the move generator (#188) and
robot strategy (#189) from Phase A; not yet wired into the UI (Phase B2/B3).
- ui/src/lib/localgame/ruleset.ts: static per-variant tile values / bag counts / blank
count, mirrored from rules.go (offline scoring is self-contained; online uses the
server alphabet). Pinned by ruleset.parity.test.ts against a Go fixture.
- bag.ts: the tile bag (fill from counts/blanks, draw-from-end, return+reshuffle) on a
deterministic in-house PRNG — a game replays from its seed, not bit-identical to a
server game (per plan).
- board.ts: the mutable board, satisfying the validator/generator read view + set().
- engine.ts: LocalGame — deal / play (reusing validate.ts) / pass / exchange / resign,
scoreless(6) & out-of-tiles end detection, end-of-game rack penalties, winner; mirrors
game.go. The end-game math is exported as pure functions, pinned against the Go engine
(engine.parity.test.ts, 9 constructed positions).
- engine.test.ts: a full-loop smoke — two robots play a whole vs_ai game to completion
via generateMoves + decide, and it is reproducible from the seed.
- backend: movegen now dumps the per-variant rulesets; a new in-package engine emitter
(endfixture_test.go, env-gated) produces the end-game golden.
Pure additive library code; no runtime behavior change (unused at runtime, bundle unchanged).
Ilia Denisov