window.matchMedia is not a function
/*See the official ject work around to mock this out for use in unit test*/
/*matchMedia.js mock file*/
Object.defineProperty(window, 'matchMedia', {
writable: true,
value: jest.fn().mockImplementation(query => ({
matches: false,
media: query,
onchange: null,
addListener: jest.fn(), // deprecated
removeListener: jest.fn(), // deprecated
addEventListener: jest.fn(),
removeEventListener: jest.fn(),
dispatchEvent: jest.fn(),
})),
});
/*---------------------------*/
import './matchMedia.mock'; // Must be imported before the tested file
import {myMethod} from './file-to-test';
describe('should test this methhod that use matchmedia', () => {
// Test the method here...
});