index.js

const express = require('express');
const app = express();
const mongoose = require('mongoose');
require('dotenv').config();
const cors = require('cors');
const path = require('path');

mongoose
  .connect(process.env.MONGODB_URI, {
    useCreateIndex: true,
    useNewUrlParser: true,
    useFindAndModify: false,
    useUnifiedTopology: true,
  })
  .then(() => console.log('MongoDB is connected!'))
  .catch((err) => console.log(err));

app.use(cors());
app.use(express.json());

app.use('/api/auth', require('./routes/user'));

if (process.env.NODE_ENV === 'production') {
  app.use(express.static('client/build'));
  app.get('*', (req, res) => {
    res.sendFile(path.resolve(__dirname, 'client', 'build', 'index.html'));
  });
}

const PORT = process.env.PORT || 5000;

app.listen(PORT, () => console.log('Server is running'));