gitlab-org--gitlab-foss/doc/development/fe_guide/axios.md

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Axios

We use Axios to communicate with the server in Vue applications and most new code.

In order to guarantee all defaults are set you should not use Axios directly, you should import Axios from axios_utils.

CSRF token

All our requests require a CSRF token. To guarantee this token is set, we are importing Axios, setting the token, and exporting axios .

This exported module should be used instead of directly using Axios to ensure the token is set.

Usage

  import axios from './lib/utils/axios_utils';

  axios.get(url)
    .then((response) => {
      // `data` is the response that was provided by the server
      const data = response.data;

      // `headers` the headers that the server responded with
      // All header names are lower cased
      const paginationData = response.headers;
    })
    .catch(() => {
      //handle the error
    });

Mock Axios response in tests

To help us mock the responses we are using axios-mock-adapter.

Advantages over spyOn():

• no need to create response objects
• does not allow call through (which we want to avoid)
• simple API to test error cases
• provides replyOnce() to allow for different responses

We have also decided against using Axios interceptors because they are not suitable for mocking.

Example

  import axios from '~/lib/utils/axios_utils';
  import MockAdapter from 'axios-mock-adapter';

  let mock;
  beforeEach(() => {
    // This sets the mock adapter on the default instance
    mock = new MockAdapter(axios);
    // Mock any GET request to /users
    // arguments for reply are (status, data, headers)
    mock.onGet('/users').reply(200, {
      users: [
        { id: 1, name: 'John Smith' }
      ]
    });
  });

  afterEach(() => {
    mock.restore();
  });

Mock poll requests in tests with Axios

Because polling function requires a header object, we need to always include an object as the third argument:

  mock.onGet('/users').reply(200, { foo: 'bar' }, {});