Adding Tests to Your v0 Project

Most v0 projects ship with zero tests. This means every change is a gamble — you might fix one thing and break three others without knowing until a user reports it. Tests are automated checks that verify your app works correctly. They run in seconds and catch bugs before your users do.

Set up Vitest with @testing-library/react. Since v0 components are mostly presentational, component tests are straightforward — render with different props and verify output. Add Playwright for testing integrated user flows

Test components with various data states: full data, empty data, null values, and loading. Test interactive elements after wiring them up. Test responsive layouts at key breakpoints. Test accessibility with automated a11y checks

Unit tests check individual functions in isolation — does this function calculate the right total? Integration tests check that multiple pieces work together — does submitting this form save to the database? End-to-end (E2E) tests simulate a real user — can someone sign up, log in, and complete a purchase? Start with E2E tests for your most critical flows, then add integration tests for your API endpoints.

Set up your tests to run automatically on every code push using GitHub Actions or a similar CI service. This way, you'll know immediately if a change breaks something. A basic CI pipeline runs your tests, checks for TypeScript errors, and builds the project. If any step fails, the push is flagged before it reaches production.