testing

The single source of truth for test rules is references/. This skill routes there. Read the docs in order and write to their rules.

The goal is not coverage. The goal is trust: after reading this test, can you trust the implementation more?

Read order

1. references/strategy.md — Define the risk you are blocking in one sentence, then place the code in the deep×wide quadrant to pick the level: unit / integration / don't-test / refactor-first.
2. references/spec.md — For high-stakes features (payment, issuance, PII, feature-flag gates, or code with fix-commit history), confirm a domain answer-sheet (정답지) first. Ask the user once; skip for obvious pure-logic utils.
3. Level doc — Write with the rules of the level strategy picked:
   • references/unit.md — pure functions, output-based, boundary+exception.
   • references/integration.md — components/hooks/loaders, MSW + React Query + data-router, user-observable results.
4. references/verification.md — If you added or changed an assertion, run the mutation loop to filter false-green. Skip for pure refactors (but record the skip).

Test names follow references/naming.md at every level.

File conventions

Tests are colocated with source (next to the file, or in a sibling __tests__/). Two Vitest projects, routed by filename:

| Kind | Extension | Vitest project | Setup | MSW | |---|---|---|---|---| | Unit | *.test.ts(x) | unit | setupTest.ts | off | | Integration | *.integration.test.tsx | integration | setupTest.ts + setupTest.integration.ts | on (onUnhandledRequest: 'error') |

Missing the .integration suffix routes the file to the unit project with no MSW → silent false green. This is the #1 filename mistake.

• Config: apps/web/vite.config.ts (test.projects). Run: pnpm --filter web test / test:run / test:coverage.
• E2E (Playwright, apps/web/tests/*.spec.ts, local Supabase) is out of scope for this skill.

Stack facts (assume these; verify if surprised)

• React Query v4, React Router v6 data-router (createBrowserRouter, loaders, lazy).
• Backend calls go to Supabase REST (/rest/v1/*, /auth/v1/*); tests mock the network with MSW, never the Supabase SDK.
• Render helper: renderWithProviders (src/test/utils/renderWithProviders.tsx). Auth: signInAs (src/test/utils/signInAs.ts) or vi.mock('@/shared/hooks/useAuth') — see integration.md.
• No Stryker; mutation verification is manual, using vitest run <file> --coverage (v8) for reachability.