Testing an HTTP post Request with mocha using nock - reactjs

Question

I'm learning how to test a frontend webapp without any connection to the API.
My problem is: I have to test an POST HTTP Request but always get an error : TypeError: loginUser(...).then is not a function.
I know my expect is not correct. I must change the data for a JWT token, and also don't know yet hot to do it.
It's a simple user authentication. Http post sending an email and password, getting back a JWT (json web token). I have to write a test to make sure I've send the correct information and get a JWT as response.
Thanks for your help
Here is my code:
//login.test.js
const expect = require('chai').expect;
const loginUser = require('../src/actions/authActions').loginUser;
const res = require('./response/loginResponse');
const nock = require('nock');
const userData = {
email: 'test#test.com',
password: '123456'
};
describe('Post loginUser', () => {
beforeEach(() => {
nock('http://localhost:3000')
.post('/api/users/login', userData )
.reply(200, res);
});
it('Post email/pwd to get a token', () => {
return loginUser(userData)
.then(res => {
//expect an object back
expect(typeof res).to.equal('object');
//Test result of name, company and location for the response
expect(res.email).to.equal('test#test.com')
expect(res.name).to.equal('Tralala!!!')
});
});
});
//authActions.js
import axios from "axios";
import setAuthToken from "../utils/setAuthToken";
import jwt_decode from "jwt-decode";
import {
GET_ERRORS,
SET_CURRENT_USER,
USER_LOADING
} from "./types";
// Login - get user token
export const loginUser = userData => dispatch => {
axios
.post("/api/users/login", userData)
.then(res => {
// Save to localStorage
// Set token to localStorage
const { token } = res.data;
localStorage.setItem("jwtToken", token);
// Set token to Auth header
setAuthToken(token);
// Decode token to get user data
const decoded = jwt_decode(token);
// Set current user
dispatch(setCurrentUser(decoded));
})
.catch(err =>
dispatch({
type: GET_ERRORS,
payload: err.response.data
})
);
// loginResponse.js
module.exports = { email: 'test#test.com',
password: '123456',
name: "Tralala!!!"
};
Actual result:
1) Post loginUser
Post email/pwd to get a token:
TypeError: loginUser(...).then is not a function
at Context.then (test/login.test.js:37:12)

Answer 1

The way you called loginUser method is not correct. This method returns another function. So, instead of loginUser(userData), you must also specify the dispatch parameter e.g. loginUser(userData)(dispatch).then().
I changed the method to specify return before axios statement
export const loginUser = userData => dispatch => {
return axios // adding return
.post("/api/users/login", userData)
.then(res => {
...
})
.catch(err =>
dispatch({
type: GET_ERRORS,
payload: err.response.data
})
);
};
for test, I may involve Sinon to spy the dispatch
it("Post email/pwd to get a token", () => {
const dispatchSpy = sinon.spy();
return loginUser(userData)(dispatchSpy).then(res => {
//expect an object back
expect(typeof res).to.equal("object");
//Test result of name, company and location for the response
expect(res.email).to.equal("test#test.com");
expect(res.name).to.equal("Tralala!!!");
});
});
Hope it helps