index.js

const express = require('express');
const mongoose = require('mongoose');
const app = express(); 
const port = 3000;

const user = require('./routes/user.route');
const product = require('./routes/product.route');
const user_products = require('./routes/user-product.route');

const swaggerUI = require('swagger-ui-express');
const swaggerDocument = require('./swagger');
const cors = require('cors');

app.use(express.json());
app.use(express.urlencoded({ extended: false }));

require('dotenv').config();

mongoose.connect(process.env.MONGODB_URI)
  .then(
    () => { console.log('Connection with database established.')},
    (err) => { console.log('Failed to connect to MongoDB!', err)}
  );  

app.use(cors({
  // origin: '*',
  origin: ['https://www.test.com', 'http://localhost:8000']
}));  
app.use('/', express.static('files'));  
app.use('/api/users', user);
app.use('/api/products', product);
app.use('/api/user-product', user_products);

app.use('/api-docs', swaggerUI.serve, swaggerUI.setup(swaggerDocument.options));

app.listen(port, () => {
  console.log('Listening on port 3000');
});