testing-patterns

Testing Next.js and Supabase applications requires unit tests with Vitest for components and hooks, integration tests for API routes, and end-to-end tests with Playwright for real user flows. This skill provides ready-to-use patterns, mock factories, and example commands to scaffold a complete testing framework for App Router projects.

Yes. Playwright end-to-end testing works with Next.js App Router and Supabase by running tests against a live application instance. This skill includes Playwright patterns that verify real user workflows, authentication states, and Supabase interactions without requiring manual test execution.

Mock data factories simulate Supabase responses, auth states, and API routes consistently across tests. This skill provides ready-to-use mock utilities and Vitest patterns that enable reliable, repeatable unit and integration tests for Supabase interactions without hitting a live database.

This skill consolidates testing across layers: Vitest handles unit and integration tests for components, hooks, and utilities; Playwright handles end-to-end user flows. A unified mock data layer prevents regressions across all test types in Next.js App Router projects.

Regression prevention requires test coverage across unit, integration, and end-to-end layers. This skill provides patterns for each layer, example test cases for typical use cases, and clear commands to run tests locally or in CI, catching breaks before deployment.