Discussion on: Testing React Hook State Changes

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Replies for: to make it work with useState we would have to mock it using jest while keeping rest of react intact. jest.requireActual can be used to achieve tha...

The following technique works well for me testing functional components with useState destructured. This is an adapted solution from that above because the mockImplementation above caused react-test-renderer tests to fail:

import * as React from 'react';

describe('Some message', () => {
    const setState = jest.fn();
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    const useStateMock: any = (initState: any) => [initState, setState];

    afterEach(() => {
      jest.clearAllMocks();
    });

    it('Is a test where we want to mock useState', () => {
          jest.spyOn(React, 'useState').mockImplementation(useStateMock);
          const wrapper = shallow(<Component {...props} />);
          // trigger setState somehow
          expect(setState).toHaveBeenCalledTimes(1);
          // Other tests here
    });
});

This is typescript, but it should work just as well in JS if you remove the type annotations