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How can I mock an ES6 module import using Jest?

Hello Guys, How are you all? Hope You all Are Fine. Today we are going to learn How can I mock an ES6 module import using Jest? in javascript. So Here I am Explain to you all the possible methods here.

Without wasting your time, Let’s start This Article.

How can I mock an ES6 module import using Jest ?

  1. How can I mock an ES6 module import using Jest ?

    can I mock an ES6 module import using Jest I've been able to solve this by using a hack involving import *. It even works for both named and default exports!

  2. How can I mock an ES6 module import using Jest ?

    can I mock an ES6 module import using Jest I've been able to solve this by using a hack involving import *. It even works for both named and default exports!

Method 1

You have to mock the module and set the spy by yourself:

import myModule from '../myModule';
import dependency from '../dependency';
jest.mock('../dependency', () => ({
  doSomething: jest.fn()
}))

describe('myModule', () => {
  it('calls the dependency with double the input', () => {
    myModule(2);
    expect(dependency.doSomething).toBeCalledWith(4);
  });
});

Method 2

To mock an ES6 dependency module default export using Jest:

import myModule from '../myModule';
import dependency from '../dependency';

jest.mock('../dependency');

// If necessary, you can place a mock implementation like this:
dependency.mockImplementation(() => 42);

describe('myModule', () => {
  it('calls the dependency once with double the input', () => {
    myModule(2);

    expect(dependency).toHaveBeenCalledTimes(1);
    expect(dependency).toHaveBeenCalledWith(4);
  });
});

The other options didn’t work for my case.

Summery

It’s all About this article. Hope all method helped you a lot. Comment below Your thoughts and your queries. Also, Comment below which method worked for you? Thank You.

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