How to mock axios.create([config]) function to return its instance methods instead of overriding them with mock?

问题

I'm trying to mock axios.create() because I'm using its instance across the app and obviously need all of its implementation which is destroyed by the mock, thus cannot get the result of the get, post method properly.

This is how the code looks like in the actual file:

 export const axiosInstance = axios.create({
        headers: {
           ...headers
        },
        transformRequest: [
            function (data, headers) {
                return data;
            },
        ],
    });
    const response = await axiosInstance.get(endpoint);

And here is the mock setup for axios inside the test file

   jest.mock('axios', () => {
        return {
            create: jest.fn(),
            get: jest.fn(() => Promise.resolve()),
        };
    }
);

How could I get all of the instance methods in the axiosInstance variable instead of just having a mock function which does nothing?

Documentation for axios.create and instance methods: https://github.com/axios/axios#instance-methods

回答1:

You can use jest's genMockFromModule. It will generate jest.fn() for each of the modules's methods and you'll be able to use .mockReturnThis() on create to return the same instance.

example:

./src/__mocks__/axios.js

const axios = jest.genMockFromModule('axios');

axios.create.mockReturnThis();

export default axios;

working example

回答2:

Ended up sticking with the axios mock and just pointing to that mock by assigning the axiosInstance pointer to created axios mock. Basically as @jonrsharpe suggested

Briefly:

import * as m from 'route';
jest.mock('axios', () => {
        return {
            create: jest.fn(),
            get: jest.fn(() => Promise.resolve()),
        };
    }
);
m.axInstance = axios

Would be very nice though if I could have gone without it.

来源：https://stackoverflow.com/questions/60428640/how-to-mock-axios-createconfig-function-to-return-its-instance-methods-inste