describe('ComponentRegistry', () => { let uut; let AppRegistry; let MyContainer, Component; beforeEach(() => { AppRegistry = {registerComponent: jest.fn()}; Component = class { // }; jest.mock('react', () => ({})); jest.mock('react-native', () => ({AppRegistry, Component})); uut = require('./ContainerRegistry'); MyContainer = class extends Component { // }; }); it('registers container component into AppRegistry', () => { expect(AppRegistry.registerComponent).not.toHaveBeenCalled(); uut.registerContainer('example.MyContainer', () => MyContainer); expect(AppRegistry.registerComponent).toHaveBeenCalledTimes(1); expect(AppRegistry.registerComponent.mock.calls[0][0]).toEqual('example.MyContainer'); }); });