I need to make unit tests for some post requests but i dont understand how.I tried with mswjs but the test passes because i'm missing something and i dont know what.I tried to test the requests in an usual way but i wasnt able to put my conditions there and it was sending only 200 status code..
To start with,this is my folder structure:

 main folder  
  nodeServer  
   public  
   routes  
  public  
  src  
   tests  

This is my try for testing the post request to /subscribe endpoint,where i should send an email as a payload and get the response that the payload was received succesefully.
subscribeFetch.test.js:

import {setupServer} from 'msw/node'
import {rest} from 'msw'

const handlers = [
    rest.post("/api/subscribe",(req,res,context)=>{

                if (!req.body || !req.body.email) {
                  return res(context.status(400).json({ error: "Wrong payload" }));
                }
            
                if (req.body.email === '[email protected]') {
                  return res(context.status(422).json({ error: "Email is already in use" }));
                }
        
                return res(
                    context.status(200),
                    context.json({email:'[email protected]'})
                )

    })
]

const server = setupServer(...handlers)

beforeAll(()=>server.listen())
afterAll(()=>server.close())
afterEach(()=>server.resetHandlers())

test('should send post request to the server',async()=>{
    server.use(
        rest.post('/api/subscribe',(req,res,ctx)=>{
            return res(
                expect (ctx.status()).toBe(200)
            )
        }
        )
    )
})

//export {handlers,rest}  

This is the subscribe post request function that i need to test:

import { validateEmail } from './email-validator.js'

export const sendSubscribe = (emailInput) => {
  const isValidEmail = validateEmail(emailInput)
  if (isValidEmail === true) {
    sendData(emailInput)
  }
}

export const sendHttpRequest = (method, url, data) => {
  return fetch(url, {
    method: method,
    body: JSON.stringify(data),
    headers: data
      ? {
        'Content-Type': 'application/json'
      }
      : {}
  }).then(response => {
    if (response.status >= 400) {
      return response.json().then(errResData => {
        const error = new Error('Something went wrong!')
        error.data = errResData
        throw error
      })
    }
    return response.json()
  })
}

const sendData = (emailInput) => {
  sendHttpRequest('POST', '/api/subscribe', {
    email: emailInput
  }).then(responseData => {
    return responseData
  }).catch(err => {
    console.log(err, err.data)
    window.alert(err.data.error)
  })
}

Files from the server:
app.js:

const express = require('express');
const path = require('path');
const cookieParser = require('cookie-parser');
const logger = require('morgan');

const indexRouter = require('./routes/index');
const communityRouter = require('./routes/community');
const analyticsRouter = require('./routes/analytics');

const app = express();
global.appRoot = path.resolve(__dirname);

app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', indexRouter);
app.use('/community', communityRouter);
app.use('/analytics', analyticsRouter);

module.exports = app;

index.js from routes folder in the server folder:

const express = require('express');
const router = express.Router();
const FileStorage = require('../services/FileStorage');

/* POST /subscribe */
router.post('/subscribe', async function (req, res) {
  try {
    if (!req.body || !req.body.email) {
      return res.status(400).json({ error: "Wrong payload" });
    }

    if (req.body.email === '[email protected]') {
      return res.status(422).json({ error: "Email is already in use" });
    }

    const data = {email: req.body.email};
    await FileStorage.writeFile('user.json', data);
    await res.json({success: true})
  } catch (e) {
    console.log(e);
    res.status(500).send('Internal error');
  }
});

/* GET /unsubscribe */
router.post('/unsubscribe', async function (req, res) {
  try {
    await FileStorage.deleteFile('user.json');
    await FileStorage.writeFile('user-analytics.json', []);
    await FileStorage.writeFile('performance-analytics.json', []);
    await res.json({success: true})
  } catch (e) {
    console.log(e);
    res.status(500).send('Internal error');
  }
});

module.exports = router;  

Please guys,help me write unit test for subscribe endpoint to match the conditions from index.js file from routes folder in the server folder,thank you in advance!

CodePudding user response：

So,i got the expected result without any library,but i dont know if its a good aproach,but at least it works :
const app = require('../../../personal-website-server/app') const request = require('supertest')

describe('POST /subscribe', () => {
    it('should give 400 status code when email is empty', async () => {
        const email = { email: '' }
        const response = await request(app).post('/subscribe').send(email)
        if (!request.body || !request.body.email) {
            expect(response.status).toBe(400)
        }
    })
    it('should give 422 status code when email is forbidden', async () => {
        const email = { email: '[email protected]' }
        const response = await request(app).post('/subscribe').send(email)
        if (request.body === '[email protected]') {
            expect(response.status).toBe(422)
        }
    })
    it('should give 200 status code when email is valid', async () => {
        const email = { email: '[email protected]' }
        const response = await request(app).post('/subscribe').send(email)
        expect(response.error).toBe(false)
        expect(response.status).toBe(200)
        expect(response.body.body).not.toBeNull()
    })
})