
React Testing Library centers tests on end-user interactions, not component internals, guiding maintainable tests that survive refactors; compare RTL with Enzyme and clarify Jest's role.
Set up and run React tests with jest and React Testing Library by understanding dev dependencies, TypeScript integration, and .test.tsx file naming with yarn test.
Learn to select elements in React tests using getByText to verify rendered text, and compare implicit and explicit assertions, error handling, and regex matching.
Learn how to use getByRole in React Testing Library to select elements by their accessibility role, including implicit roles like text box for input, with examples using labels and placeholders.
Learn how query by fits alongside get by in React Testing Library, exploring query by role and other search variants, and how non-existent elements return null for robust assertions.
Learn to write more meaningful tests by mocking the get user function, refactoring into a dedicated module, and using waitFor to validate a single API call and avoid side effects.
Explore the find by text variant in rtl by mocking the get user function, rendering the app, and using find by text to await and verify asynchronous user data.
Learn to query multiple elements with react testing library using get all by text and get all by role, plus label and placeholder text selectors, and verify counts for tests.
Learn to simulate user interactions with fireEvent in React Testing Library, typing into inputs and validating on-screen display, and compare RTL's user-focused approach with enzyme's internals.
Use the user event API to simulate browser interactions in RTL tests, replacing fire event with await userEvent.type on a textbox retrieved by getByRole, triggering change and key down events.
Learn how to measure and optimize test coverage in a React app using RTL, including running yarn test --coverage, mocking API calls, and configuring coverage in package.json.
Debug React tests with Chrome and Visual Studio Code by adding a Launch.json, running Jest in band, and using the debug console to inspect results.
Welcome to testing React components with React Testing Library! In this course, you will learn lots of things. You will learn:
The principles of Test Driven Development
Know what is React Testing Library (RTL) and its differences with Enzyme (another popular test framework for React)
Understand how Create React App (CRA) works.
Understand how Jest works with RTL
How to test with RTL and query elements with:
getBy, queryBy, findBy, getAllBy, queryAllBy, findAllBy
How to simulate user interaction with the fireEvent API
How to simulate user interaction with the userEvent API
Testing components in isolation (unit tests)
Learn about coverage and debugging
How to mock 3rd party libraries like Axios and mock a GET request
Learn about the pitfalls of CRA
You will have all the fundamental tools to test any React component and have that coverage at 100%!
Have fun, and never stop learning!