server.js

const express = require('express');
const path = require('path');
const userRouter = require('./routes/api/users');
const bodyParser = require('body-parser');
const cors = require('cors');
const groupsRouter = require('./routes/api/groups')
const app = express();
if (process.env.NODE_ENV !== 'production') {
  require('dotenv').config();
}

const port = process.env.PORT || 5000
app.use(bodyParser.json());
app.use(cors());

const mongoose = require('mongoose');

mongoose.connect(process.env.MONGODB_URI, { useNewUrlParser: true, useUnifiedTopology: true });

// When successfully connected
mongoose.connection.on('connected', () => {
	console.log('Established Mongoose Default Connection');
});

// When connection throws an error
mongoose.connection.on('error', err => {
	console.log('Mongoose Default Connection Error : ' + err);
});

app.use('/api/users', userRouter);
app.use('/api/groups', groupsRouter)

if (process.env.NODE_ENV === 'production') {
  // Set static folder
  app.use(express.static('client/build'));

  app.get('*', (req, res) => {
    res.sendFile(path.resolve(__dirname, 'client', 'build', 'index.html'));
  });
}

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