Module 6 of 11

Testing in Depth

From the testing trophy to Playwright: unit tests, API integration tests, component tests, and end-to-end coverage that runs in CI.

4 lessons

~14 hours

140 XP

What to test and why: the testing trophy, writing unit tests with Vitest, mocking without lying to yourself, and using coverage as a map.

Test the real request pipeline with Supertest and an in-memory database: factories, seeders, auth flows, and clean isolation.

React Testing Library done right: querying like a user, simulating interactions, mocking the network with MSW, and asserting accessibility.

Drive a real browser: locators, auto-waiting, authentication state, network mocking, trace viewer debugging, and a CI-ready pipeline.