The first step in the Jest tutorial is to define the document object. This object represents the DOM tree and allows you to run scripts within it. The code you write inside a Jest document will work just like it would in a browser. This tutorial will also cover Pre-commit hooks and Snapshot testing.
Hooks for setup and cleanup
Jest provides hooks to perform setup and cleanup tasks. These hooks are executed before and after every test in a test suite. They can also be used to perform teardown tasks. These hooks should be run before and after any error or failure in a test. Hooks can be used to specify the order in which tests are executed.
before blocks apply to all tests in a file. A described block groups all tests together. The beforeAll blocks apply to all tests inside of the describe block. Similarly, beforeEach at the top level will execute before the beforeEach inside a describe block. In this way, hooks are executed in an order that can be used to test for side effects.
Hooks for setup and cleanup in Jest allow test developers to easily test the results of their tests. By adding these hooks, developers can add test-specific logic to a test. For example, they can include a callback that renders a component. This way, the test component can be rendered without the need for a native mobile environment.