index.js

const express = require("express");
const path = require('path');
const mongoose = require('mongoose');
const routes = require('./server/routes');
const formData = require('express-form-data');

require('dotenv').config();

const app = express();
app.use(express.json());
app.use(formData.parse());

mongoose.connect(process.env.DB_URL, {
   useNewUrlParser: true,
   useCreateIndex: true,
   useUnifiedTopology: true,
   useFindAndModify: false
  });
const db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', () => {
  console.log("MongoDB database connection established!");
});


routes(app);

app.use(express.static(path.join(__dirname, 'client/build')));

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

app.listen(process.env.PORT || 4000, () => console.log('APP listening on 4000'));