can anyone tell me how to wait in jest for a mocked promise to resolve when mounting a component that calls componendDidMount()
?
class Something extends React.Component {
state = {
res: null,
};
componentDidMount() {
API.get().then(res => this.setState({ res }));
}
render() {
if (!!this.state.res) return
return <span>user: ${this.state.res.user}</span>;
}
}
the API.get()
is mocked in my jest test
data = [
'user': 1,
'name': 'bob'
];
function mockPromiseResolution(response) {
return new Promise((resolve, reject) => {
process.nextTick(
resolve(response)
);
});
}
const API = {
get: () => mockPromiseResolution(data),
};
Then my testing file:
import { API } from 'api';
import { API as mockAPI } from '__mocks/api';
API.get = jest.fn().mockImplementation(mockAPI.get);
describe('Something Component', () => {
it('renders after data loads', () => {
const wrapper = mount(<Something />);
expect(mountToJson(wrapper)).toMatchSnapshot();
// here is where I dont know how to wait to do the expect until the mock promise does its nextTick and resolves
});
});
The issue is that I the expect(mountToJson(wrapper))
is returning null
because the mocked api call and lifecycle methods of <Something />
haven't gone through yet.
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