api-mockinglisted

# API Mocking (pointer) MSW handler API, browser/node setup, install commands and request-interception internals are canonical at vendor docs and drift on each release: - **MSW** — [mswjs.io](https://mswjs.io) (recommended default; browser worker + Node server, single handler set) - **nock** — [github.com/nock/nock](https://github.com/nock/nock) (Node-only HTTP interception) - **json-server** — [github.com/typicode/json-server](https://github.com/typicode/json-server) (full REST fake server from a JSON file) - **Mirage JS** — [miragejs.com](https://miragejs.com) (browser-only, models + factories) ## Tool selection (version-agnostic) ``` Need to mock HTTP for tests/dev? ├── Browser AND Node from one handler set → MSW ├── Node-only unit tests, low ceremony → nock ├── Need a stateful REST fake server (CRUD) → json-server └── Browser-only with relational fixtures (factories) → Mirage JS ``` ## Foundation discipline (keep across releases) - **Type-safe mocks**: derive mock payloads from the same TypeScript types as the real API (e.g. shared `types/api.ts`). A mock that compiles against stale types is the #1 source of mock-prod divergence. - **Reset between tests**: always `resetHandlers()` (MSW) or `cleanAll()` (nock) in `afterEach` — leaked state across tests is a debugging tax. - **Realistic failure modes**: simulate 5xx/timeouts/auth errors, not just happy paths. The mock is only useful if it exercises the same edge cases as prod. - **Unhandled = error**: in tests use `on