I'm trying to create a simple test in Jest that should check if an imported function is called inside useEffect in the component's lifecycle.

index.js

import { myFunc } from './myFunctions';


const myComponent = () => {

   useEffect(() => {
      myFunc()
   }, [])

   return ()
}

 export default MyComponent

And now I want to create a test index.test.js file to test if that myFunc was called one time. I've got a special function that renders the mocked component (it's called prepare()).

index.test.js

import * as myFunctions from './myFunctions';

describe('when the component renders', () => {

   it('the function should be called once', () => {

       const spy = jest.spyOn(myFunctions, 'myFunc');
       prepare(); // Function rendering myComponent
       expect(spy).toHaveBeenCalledTimes(1);
  });

myFunctions.js

export const myFunc = () => {

   doSomething()

}

...

My error

expect(jest.fn()).toHaveBeenCalledTimes(expected)

    Expected number of calls: 1
    Received number of calls: 0