server.js

const express = require("express");
const mongoose = require("mongoose");
const bodyParser = require("body-parser");
const passport = require("passport");
const users = require("./routes/api/usersRoute");
const products = require("./routes/api/productsRoute");
require('dotenv').config();
const app = express();
// Bodyparser middleware
app.use(
  bodyParser.urlencoded({
    extended: false
  })
);
app.use(bodyParser.json());
// DB Config
const db = require("./config/keys").mongoURI;
// Connect to MongoDB
mongoose.connect(db, {
        useNewUrlParser: true
    })
    .then(() => console.log("MongoDB successfully connected"))
    .catch(err => console.log(err));


app.use(function(req, res, next) {
    res.header('Access-Control-Allow-Origin', '*');
    res.header('Access-Control-Allow-Methods', 'GET, PUT, POST, DELETE, OPTIONS');
    res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization, Content-Length, X-Requested-With');
    if ('OPTIONS' === req.method) {
        res.send(200);
    } else {
        next();
    }
});

// Passport middleware
app.use(passport.initialize());
// Passport config
require("./config/passport")(passport);
// Routes
app.use("/api/users", users);
app.use("/api/products", products);
const port = process.env.PORT || 5000;
app.listen(port, () => console.log(`Server up and running on port ${port} !`));