A Jest mock for superagent. Place in your __mocks__ directory.

superagent.js

llet mockDelay;
let mockError;
let mockResponse = {
  get: jest.fn(),
  ok: true,
  status: 200,
  toError: jest.fn(),
};

let mockResponseBodies;
let responseBodiesIndex;

const Request = {
  __setMockDelay(boolValue) {
    mockDelay = boolValue;
  },
  __setMockError(mockErr) {
    mockError = mockErr;
  },
  __setMockResponse(mockRes) {
    mockResponse = mockRes;
  },
  __setMockResponseBodies(bodies) {
    mockResponseBodies = bodies;
    responseBodiesIndex = -1;
  },
  __setMockResponseBody(body) {
    mockResponse.body = body;
    responseBodiesIndex = undefined;
  },
  accept: jest.fn().mockReturnThis(),
  catch: jest.fn().mockReturnThis(),
  delete: jest.fn().mockReturnThis(),
  end: jest.fn().mockImplementation(callback => {
    if (mockDelay) {
      this.delayTimer = setTimeout(callback, 0, mockError, mockResponse);

      return;
    }

    callback(mockError, mockResponse);
  }),
  field: jest.fn().mockReturnThis(),
  get: jest.fn().mockReturnThis(),
  head: jest.fn().mockReturnThis(),
  patch: jest.fn().mockReturnThis(),
  post: jest.fn().mockReturnThis(),
  put: jest.fn().mockReturnThis(),
  query: jest.fn().mockReturnThis(),
  redirects: jest.fn().mockReturnThis(),
  send: jest.fn().mockReturnThis(),
  set: jest.fn().mockReturnThis(),
  retry: jest.fn().mockReturnThis(),
  then: cb =>
    new Promise((resolve, reject) => {
      if (typeof responseBodiesIndex !== 'undefined') {
        responseBodiesIndex += 1;
        mockResponse.body = mockResponseBodies[responseBodiesIndex];
      }
      if (mockError) {
        reject(mockError);
      } else {
        resolve(cb(mockResponse));
      }
    }),
  timeout: jest.fn().mockReturnThis(),
  type: jest.fn().mockReturnThis(),
};

export default Request;

Hey thanks for sharing this. If you use promise chaining though, the mock will fail. You can add this to your mock request and it should do the trick:

then: jest.fn().mockImplementation(callback => {
    return new Promise((resolve, reject) => {
      if (mockError) {
        return reject(mockError)
      }
      return resolve(callback(mockResponse))
    })
  }),

Thank you @gbalbuena for this great gist, and also thank the .then advise from @frankcalise.
I use superagent-bluebird-promise and stuck on mock. I follow both of your advise and it works.

__mocks__/superagent-bluebird-promise.js

let query = null

const Request = {
  get: jest.fn().mockReturnThis(),
  query: jest.fn(function(q) {
        query = q
        return this
  }),
  then: jest.fn().mockImplementation(callback => {
    if (!query['ANY_PARAM_KEY'])
      return Promise.reject(mockError)
    return Promise.resolve(callback(mockResponse))
  })
}

export default Request;

@gbalbuena What about restoring the mocks?

@fire-cracker we reset the mocks like this:

beforeEach(() => {
  request.__setMockError(null);
  request.__setMockResponse({
    get: jest.fn(),
    ok: true,
    status: 200,
    toError: jest.fn(),
  });
});

@gbalbuena thanks for the great gist! We had to extend it by adding a __setMockResponseBodies to be able to test a function that made multiple successive requests.

In case anybody else needs to do the same thing, this is what it looks like:

let mockDelay;
let mockError;
let mockResponse = {
  get: jest.fn(),
  ok: true,
  status: 200,
  toError: jest.fn(),
};

let mockResponseBodies;
let responseBodiesIndex;

const Request = {
  __setMockDelay(boolValue) {
    mockDelay = boolValue;
  },
  __setMockError(mockErr) {
    mockError = mockErr;
  },
  __setMockResponse(mockRes) {
    mockResponse = mockRes;
  },
  __setMockResponseBodies(bodies) {
    mockResponseBodies = bodies;
    responseBodiesIndex = -1;
  },
  __setMockResponseBody(body) {
    mockResponse.body = body;
    responseBodiesIndex = undefined;
  },
  accept: jest.fn().mockReturnThis(),
  catch: jest.fn().mockReturnThis(),
  delete: jest.fn().mockReturnThis(),
  end: jest.fn().mockImplementation(callback => {
    if (mockDelay) {
      this.delayTimer = setTimeout(callback, 0, mockError, mockResponse);

      return;
    }

    callback(mockError, mockResponse);
  }),
  field: jest.fn().mockReturnThis(),
  get: jest.fn().mockReturnThis(),
  head: jest.fn().mockReturnThis(),
  patch: jest.fn().mockReturnThis(),
  post: jest.fn().mockReturnThis(),
  put: jest.fn().mockReturnThis(),
  query: jest.fn().mockReturnThis(),
  redirects: jest.fn().mockReturnThis(),
  send: jest.fn().mockReturnThis(),
  set: jest.fn().mockReturnThis(),
  then: cb =>
    new Promise((resolve, reject) => {
      if (typeof responseBodiesIndex !== 'undefined') {
        responseBodiesIndex += 1;
        mockResponse.body = mockResponseBodies[responseBodiesIndex];
      }
      if (mockError) {
        reject(mockError);
      } else {
        resolve(cb(mockResponse));
      }
    }),
  timeout: jest.fn().mockReturnThis(),
  type: jest.fn().mockReturnThis(),
};

export default Request;

Woow, thanks for all the contributions

I haven't worked again with superagent, this is super complete now :)

How to use this mocks buddy? I mean how to import that thing? Is it automatically resolve the object with superagent?

• Sorry for noob question

thanks for sharing this code, i solved my problem already

first let has two l's

We could also add for retry function:

retry: jest.fn().mockReturnThis(),

updated, thanks @Bazze

Can someone show an example of a Jest test using this mock-up? Especially a test when the superagent call is not being performed in the test itself, but in a function called by the test.

Example:

test('demo', async () => {
  await functionThatUsesSuperagent();
});

Bonus: Doing the test in Typescript 😊

there is a typo on line 1.