Testing
Ship with confidence: unit, integration and end-to-end tests.
Tests are code that checks your code, so you can change things without fear. This track starts with your first expect in Vitest and ends with a team's whole safety net: clear unit tests, edge cases and boundaries, test doubles for time and randomness, an integration test for a Go web handler, end-to-end tests that drive a real browser with Playwright, flaky tests and how to kill them, and the red, green, refactor loop of TDD.
Examples use TypeScript with Vitest, one Go test and Playwright, all on the features of a small social app called Nova: points, tiers, leaderboards, sign-ups and posts. Basic JavaScript or TypeScript is all you need to start.
- Lessons
- 14
- Time
- 2 h
- Level
- Beginner
- Bronze open
- Silver open
- Gold locked
Ready to prove it?
Three exams are waiting: Bronze, Silver and Gold.
What you'll be able to do
- Write clear unit tests with Vitest's
describe,itandexpect - Hunt edge cases and test both sides of every boundary
- Replace clocks, randomness and email with test doubles
- Test a Go HTTP handler with
httptest - Drive a real browser with Playwright, without sleeps or hardcoded ports
- Work in a red, green, refactor loop and read coverage wisely
The journey
1 Module 1Your first tests
Why tests matter, the shape of a good test, edge cases and test doubles.
0 / 52 Module 2Testing like a team
The test pyramid, integration and end-to-end tests, flaky tests and TDD.
0 / 53 Module 3The road ahead
Beyond the basics: property-based tests, contract tests, mutation testing and load tests.
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