best times only improve; achievement unlock announces on the transition
only, so popup/Steam subscribers cannot double-fire; statistics are
increase-only (IncrementStat took any int).
RelockAchievement is console-only and documented as not reaching Steam -
a Steam achievement cannot be un-earned, so the disagreement is
permanent and deliberate.
refactor: extract EventLog, composed by both aggregates now that the
duplication actually exists. 34 tests.
Lives (floors at zero, exhaustion observable), LevelId, SkillId,
PlaythroughId (never self-generates, keeps tests deterministic),
StatName enum, LevelTime rejects NaN/infinity.
14 tests. Arithmetic/comparison members deferred to the slices whose
behaviour needs them rather than added speculatively.
three bug-encoding invariants, one red/green cycle each:
- Coins.TrySubtract fails instead of clamping
- LevelTime rejects zero (continued-run zero best-times)
- SkillLevel has no zero (unowned is absence, not Level=1)
plan: drop signed NetCoins; add Attempt outcome as idempotency guard
