I have a function which is called on module creation, and I'd like to ensure that it is actually being used with a test.
// MyComponent.js
import {internalComponentFactory} from './factories';
const InternalComponent = internalComponentFactory([1,2,3]);
export const MyComponent = () => {
return <InternalComponent locale={'en-us'} />
}
I've tried various flavors of this:
// MyComponent.test.js
import {MyComponent} from './MyComponent';
import {internalComponentFactory} from './factories;
jest.mock('./factories', () => ({
internalComponentFactory: jest.fn()
}));
describe('src/MyComponent', () => {
it('leverages the internal component factory', () => {
expect(internalComponentFactory).toHaveBeenCalledTimes(1);
});
})
However, this ends up failing the test with a count of 0. Likely the case is a timing issue - the module is created once, and it seems before the mock is even applied.
I have also tried placing a require statement within the actual test, but it intermittently fails.
How would I go about mocking the internalComponentFactory call?
The module can be imported dynamically later in the test using import() function.
I managed to make it work like this:
// import { MyComponent } from './MyComponent';
import { internalComponentFactory } from './factories';
jest.mock('./factories', () => ({
internalComponentFactory: jest.fn()
}));
describe('src/MyComponent', () => {
it('leverages the internal component factory', async () => {
await import('./MyComponent');
expect(internalComponentFactory).toHaveBeenCalledTimes(1);
expect(internalComponentFactory).toHaveBeenCalledWith([1, 2, 3]);
});
})