TypeError when using vitest: default is not a function

Question

I'm using vitest to do some unit testing in my vue application. I've written some tests but they fail with the error message: "TypeError: default value is not a function". But I'm not using a function named default() in my code.

import getInfo from './info';

vi.mock('axios', () => {
    return {
        default: {
            get: vi.fn()
        }
    }
});

test('fn getInfo() should request api with axios.get url', async () => {
    const spyAxios = vi.spyOn(axios, 'get');
    await getInfo('1234');
    expect(spyAxios).toHaveBeenCalledWith(`${process.env.VUE_APP_API_BASE_URL}`);
});

If I then execute npm run test the result is as follows:

FAIL  src/api/info/info.test.js > fn getInfo() should request api with axios.get url
TypeError: default is not a function
 ❯ src/api/info/info.test.js:61:22
     59| test('fn getInfo() should request api with axios.get url', async () => {
     60|     const spyAxios = vi.spyOn(axios, 'get');
     61|     await getInfo('1234');
       |                  ^
     62|     expect(spyAxios).toHaveBeenCalledWith(`${process.env.VUE_APP_API_BASE_URL}`);
     63| });

info.ts file looks like this:

import { useLoginStore } from "../../store/LoginStore";
import axios from "axios";

// eslint-disable-next-line
export async function getInfo(param: string) : Promise<any> {
    const loginStore = useLoginStore();
    axios.defaults.headers.common = {'Authorization': `Bearer ${loginStore.accessToken}`};
    
    const request = await axios.get(
        process.env.VUE_APP_API_BASE_URL
    );

    if (request?.status == 200) {
        return request.data;
    }
    else {
        return null;
    }
}

Does anyone know what's going on?

Answer 1

The default attribute in the returned object is not a function (default: {...}). Instead, you will return something like this:

vi.mock('axios', () => ({
  default: () => ({
    get: vi.fn(),
    post: vi.fn(),
  }),
}));