This hands-on course provides a practical introduction to testing JavaScript and TypeScript applications using Jest, one of the most popular testing frameworks in the JavaScript ecosystem. If you’ve ever wanted to write reliable tests, catch bugs earlier, and build more confidence in your code, this course is for you. We focus on learning by doing. There are no theory-heavy slides or long explanations. Instead, you’ll start writing real tests from the very first lessons and build practical skills that you can immediately use in your own projects.
You’ll begin by setting up Jest in a project and understanding how the testing workflow works. From there, we’ll cover unit testing for functions and modules, working with assertions and matchers, and understanding how to read test results. As the course progresses, you’ll learn how to test asynchronous code using promises and async/await, use mocks and spies to isolate dependencies, and write cleaner, more maintainable test suites.
We’ll also cover testing TypeScript code, handling edge cases, organizing tests properly, and debugging failing tests effectively. Throughout the course, you’ll work with practical examples based on real-world coding scenarios, helping you understand not just how to write tests, but why they matter.
