Default Jest preset for WordPress development.

Install the module

npm install @wordpress/jest-preset-default --save-dev

{
  "preset": "@wordpress/jest-preset-default"
}

• moduleNameMapper - all css and scss files containing CSS styles will be stubbed out.
• modulePaths - the root dir of the project is used as a location to search when resolving modules.
• setupFiles - runs code before each test which sets up global variables required in the testing environment.
• setupTestFrameworkScriptFile - runs code which adds improved support for Console object and React components to the testing framework before each test.
• testMatch- includes /test/ subfolder in the glob patterns Jest uses to detect test files. It detects only test files containing .js extension.
• timers - use of fake timers for functions such as setTimeout is enabled.
• transform - adds support for PEG.js transformed necessary for WordPress blocks. It also keeps the default babel-jest transformer.
• verbose - each individual test won't be reported during the run.

It is also possible to override the script that runs some code to configure or set up the testing framework before each test. To do so you will need to create setup-test-framework.js inside your project with the following content:

// You can still load the default script provided by this setup
import '@wordpress/jest-preset-default';

// Your code goes here