Mocking React Components and Functions using Jest for Beginners - React.js Testing Tutorial #5

In this tutorial we are going to learn how to mock components and functions using the built-in features in jest. We will use jest.mock, jest.spyOn, jest.fn(), _mocks_ folder and others. Manual mocks are used to stub out functionality with mock data. For example, instead of accessing a remote resource like a website or a database, you might want to create a manual mock that allows you to use fake data. This ensures your tests will be fast and not flaky. Mock functions allow you to test the links between code by erasing the actual implementation of a function, capturing calls to the function (and the parameters passed in those calls), capturing instances of constructor functions when instantiated with new, and allowing test-time configuration of return values. There are two ways to mock functions: Either by creating a mock function to use in test code, or writing a manual mock to override a module dependency. ---- GitHub repository: https://github.com/bmvantunes/youtube... ---- All the videos in this series (React.js Testing Tutorial):    • React.js Unit Testing and Integration Test...   ---- Join the channel to support my content:    / @brunoantunespt   ----- Timeline: 00:00 Intro 00:18 Example 1 06:55 Example 2a: Button 09:40 Example 2b: Data Grid 17:00 Example 3 19:50 Example 4 22:06 Example 5: Avoid mocking everywhere the same component 25:50 Outro ---- Follow me on: Twitter:   / bmvantunes   Dev.to: https://dev.to/bmvantunes Website: https://brunoantunes.net GitHub: https://github.com/bmvantunes LinkedIn:   / bmvantunes   #jest #ReactTestingLibrary #react