server.js

const express = require('express');
const bodyParser = require('body-parser');
const cors = require('cors');

const app = express();
const port = 3000;

app.use(cors());

const jsonParser = bodyParser.json();

const users = [];
const messages = [
  { body: 'test message', sentBy: 'test user' }
];

app.post('/login', jsonParser, (req, res) => {
  const user = {
    login: req.body.login
  }
  users.push(user);
  console.log(`User ${user.login} joined`);
  return res.json(user);
})

app.post('/sendMessage', jsonParser, (req, res) => {
  const message = {
    body: req.body.message,
    sentBy: req.body.login
  }
  messages.push(message);
  return res.json(message);
})

app.get('/messages', (req, res) => {
  return res.json(messages);
})

app.get('/', (req, res) => res.send("stary tekst"));

app.listen(port, () => console.log(`Example app listening on port ${port}!`));