Inspecting fetch URL and options

[robcaldecott]

When testing it would sometimes be useful to inspect the fetch URL and options being passed: checking for the correct headers, POST body content, etc. Is there any way to achieve this using jest-fetch-mock?

[jefflau]

Hi @robcaldecott

jest-fetch-mock does support it because the jest mocks underlying architecture supports it. I probably need to document it better, but it works the same way jest mocks work. You can copy these two files api.js and api.test.js into your project to see how it works. The docs for mocks in jest are here: https://facebook.github.io/jest/docs/en/mock-functions.html

//api.js
import 'isomorphic-fetch';

export function getStuff() {
  return fetch('https://facebook.com').then(stuff => {
    console.log(stuff);
  });
}

//api.test.js
import { getStuff } from './api';

it('mock test', () => {
  const mock = fetch.mockResponse(JSON.stringify({ access_token: '12345' }));
  getStuff();

  console.log(fetch.mock.calls);

  expect(fetch.mock.calls.length).toEqual(1);
  expect(fetch.mock.calls[0][0]).toEqual('https://facebook.com');

  fetch.resetMocks();

  console.log(fetch.mock.calls);
});

[robcaldecott]

Of course. I should have worked that out. :) Many thanks! Works perfectly.

[jefflau]

Cool :) My fault. I should have documented better.

Sorry for the slow reply. Hope it works good now!

I'll leave this issue up until I get the documentation sorted out

[jefflau]

Added documentation to this so hopefully it won't be an issue. Closing this!