testing-infrastructure

Vitest provides scalable testing infrastructure for monorepos by centralizing configuration across unit tests and Storybook tests. Use pnpm workspaces to run tests per package with `pnpm test --filter @package-name`, then apply React Testing Library patterns for user-focused assertions and MSW for API mocking to ensure consistent test behavior across your monorepo.

MSW-based API mocking intercepts HTTP requests at the network layer, letting you define mock handlers once and reuse them across unit and integration tests. This approach avoids brittle module-level mocks and ensures your tests validate real request/response patterns without hitting live endpoints.

Use the test-suite-runner agent to execute comprehensive tests across your monorepo in CI, generating detailed failure reports that pinpoint which Vitest configuration, React Testing Library assertion, or mock setup caused the failure. This enables rapid debugging without manual log parsing.

Yes, Storybook's addon-vitest integration lets you run Vitest tests directly against your stories, enabling you to validate component rendering, interactions, and visual behavior alongside unit tests in the same configuration and test runner.

No, centralized Vitest configuration satisfies both unit test execution and Storybook addon-vitest requirements. A single setup handles mocking, module resolution, and test discovery, eliminating configuration duplication across testing contexts.

Combine React Testing Library's user-interaction focus with mock data utilities and MSW API mocks to test components realistically. This skill provides pre-built patterns for testing hooks, context providers, and async interactions that scale across multiple packages without coupling tests to implementation details.