Jest - mock function inside another module function - node.js

Question

I'm trying to mock the return value (or implementation) of the functions inside another module's function with Jest. I need to test different scenarios (function throws error, returns null, returns an object, etc...)
That module (userService) returns a function that returns an object with that functions:
userService.js (I want to mock the return value of findUser & createUser)
...
function userService(userModel) {
async function findUser(userQuery) {
...
return foundUser;
}
async function createUser(user) {
...
return createdUser;
}
return { findUser, createUser };
}
module.exports = userService;
And I'm testing authStravaController, which uses that service functions:
authStravaController
...
const authStravaServiceRaw = require('../../services/authStravaService');
const userServiceRaw = require('../../services/userService');
const bikeServiceRaw = require('../../services/bikeService');
...
function authStravaController(userModel, bikeModel) {
const { findUser, createUser } = userServiceRaw(userModel); <-- WANT TO MOCK THAT FUNCTIONS
async function authStrava({ body: { authCode } }, res) {
...
try {
...
const findUserQuery = {
stravaUserId: stravaBasicUser.stravaUserId,
};
authUser = await findUser(findUserQuery); <-- MOCK THIS FUNCTION RETURN MULTIPLE TIMES
if (!authUser) {
resStatus = CREATED;
createdUser = await createUser(stravaBasicUser); <-- SAME
...
createdUser.bikes = createdBikes.map((bike) => bike._id);
createdUser.save();
authUser = { createdUser, createdBikes };
}
return handleResponseSuccess(res, resStatus, authUser);
} catch (authStravaError) {
return handleResponseError(res, authStravaError);
}
}
return { authStrava };
}
module.exports = authStravaController;
At the moment I've been able to mock the function return value just 1 time, and I can't find a way to rewrite it, so now I can only test 1 scenario
This code at the top of the file let me test 1 scenario
jest.mock('../../services/userService', () => () => ({
findUser: jest.fn().mockReturnValue(1),
createUser: jest.fn().mockReturnValue({ username: 'userName', save: jest.fn() }),
}));
I've tried to mock it in multiple ways and can't get it to work, how could I do it to test different return values:
findUser: jest.fn().mockReturnValue(1),
findUser: jest.fn().mockReturnValue(undefined),
findUser: jest.fn().mockReturnValue({user:'username'}),
etc...
Thanks!

Answer 1

I fixed it importing all the services outside the controller function, at the top of the file.
This way I can mock the returnValue of any function.