service-boundary-and-nativelisted

Wires every side effect and native channel as an injectable interface behind a Provider that throws UnimplementedError until the composition root overrides it, with one live impl per flavor, value-typed signatures returning typed results, hand-written contract-honouring fakes over mocks, MethodChannel quarantined to one lib/native/ directory, and versioned cross-language contracts edited on both sides in one commit. Use when adding or changing a ShareService/AnalyticsService/RemoteConfigService or any side-effect port, injecting a Clock (package:clock) via clockProvider, a MethodChannel/platform channel or native widget bridge, a flavor entrypoint (main_*.dart) or per-flavor provider override, a shared-file/JSON contract mirrored in Kotlin/Swift, replacing a stray DateTime.now() or direct SDK call inside a widget/notifier/repository, or wiring a fake via ProviderScope(overrides:) in tests.
zakariaf/CatchLaw · ★ 0 · AI & Automation · score 55

Install: claude install-skill zakariaf/CatchLaw

# Service boundary and native Every platform capability — reading "now", sharing, logging an event, fetching remote flags, calling a MethodChannel — crosses the app's layers as an **injected interface**. The interface names value types only; the concrete SDK lives in exactly one class; the composition root (`main`) wires one live impl; tests wire a deterministic fake. **Abstract exactly what cannot run in a test — nothing more.** This is the seam that keeps features pure, SDKs swappable, and the whole app testable headlessly. Read the reference for the task at hand: - `references/service-interface.md` — typed outcomes vs bool/throw, exhaustiveness, `@useResult`, hand-written env-fakes, the arrow-callback Future-drop hole, single write path. - `references/native-channels.md` — MethodChannel placement, the cross-language contract ownership table, versioned-file-vs-`shared_preferences` traps, native-fast-path independence, the round-trip `integration_test`. - `references/multi-flavor.md` — line-for-line composition roots, build flavors over runtime detection, per-flavor plugin pins, the banned-dependency CI graph gate. Run `scripts/check-service-boundaries.sh` and `scripts/check-flavor-graph.sh` before a PR. ## Non-negotiable rules 1. **Every side effect is an injected interface, never a concrete SDK at the call site.** Features, Notifiers, and repositories depend on the *interface*; the app imports the real SDK in exactly one live-impl class. WHY: one seam to swap, one pla