Testing

Lessons

1. 1

   Why Testing Matters and the Testing Pyramid

   Free

   Explain the testing pyramid (unit, integration, e2e), what each layer tests and costs, and the limits of coverage as a metric.

   Beginner·25 min
2. 2

   Unit Testing Fundamentals

   Write a good unit test with Arrange-Act-Assert, keep tests isolated, and use mocking and stubbing correctly.

   Beginner·40 min
3. 3

   Unit Testing in JavaScript and TypeScript

   Test functions and modules with Vitest/Jest, mock modules and APIs, and use snapshot testing where it fits.

   Intermediate·50 min
4. 4

   Unit Testing in Python

   Test Python code with pytest fixtures and parametrize, and mock dependencies with unittest.mock.

   Intermediate·45 min
5. 5

   Integration Testing

   Test multiple components together, including real database interactions and API routes, without over-mocking.

   Intermediate·45 min
6. 6

   End-to-End Testing with Playwright

   Automate a browser to test a real user flow end to end, and run those tests headless in CI.

   Intermediate·50 min
7. 7

   Test-Driven Development

   Run the red-green-refactor cycle and judge honestly when TDD helps and when it slows you down.

   Intermediate·40 min
8. 8

   Running Tests in CI

   Run the test suite on every pull request, fail the build on failure, and publish coverage reports.

   Intermediate·40 min
9. 9

   Passion Project: Add a Real Test Suite

   Take an untested project and build a full pyramid of tests wired into CI with a coverage gate.

   Advanced·90 min
10. 10

    Testing Job Readiness

    Translate testing skills into a resume, portfolio, and interview prep for SDET, QA Automation, and engineering roles.

    Intermediate·30 min