app.js

var createError = require("http-errors");
var express = require("express");
var path = require("path");
var cookieParser = require("cookie-parser");
const bodyParser = require("body-parser");
var logger = require("morgan");
var debug = require("debug")("api:server");
var http = require("http");
require("dotenv").config();
var cors = require("cors");
require("./config/database");
var route = require("./routes/route");

var app = express();

app.use(cors());
app.use(logger("dev"));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
app.use(cookieParser());

// route
app.use(route);

// catch 404 and forward to error handler
app.use(function (req, res, next) {
    next(createError(404));
});

// error handler
app.use(function (err, req, res, next) {
    // set locals, only providing error in development
    res.locals.message = err.message;
    res.locals.error = req.app.get("env") === "development" ? err : {};

    // render the error page
    res.status(err.status || 500);
    res.json({ error: err });
});

// Get port from environment and store in Express.
var port = normalizePort(process.env.PORT || "3000");
app.set("port", port);

// Create HTTP server.
var server = http.createServer(app);

// Listen on provided port, on all network interfaces.
server.listen(port);
server.on("error", onError);
server.on("listening", onListening);

// Normalize a port into a number, string, or false.
function normalizePort(val) {
    var port = parseInt(val, 10);

    if (isNaN(port)) {
        // named pipe
        return val;
    }

    if (port >= 0) {
        // port number
        return port;
    }

    return false;
}

// Event listener for HTTP server "error" event.
function onError(error) {
    if (error.syscall !== "listen") {
        throw error;
    }

    var bind = typeof port === "string" ? "Pipe " + port : "Port " + port;

    // handle specific listen errors with friendly messages
    switch (error.code) {
        case "EACCES":
            console.error(bind + " requires elevated privileges");
            process.exit(1);
            break;
        case "EADDRINUSE":
            console.error(bind + " is already in use");
            process.exit(1);
            break;
        default:
            throw error;
    }
}

// Event listener for HTTP server "listening" event.
function onListening() {
    var addr = server.address();
    var bind = typeof addr === "string" ? "pipe " + addr : "port " + addr.port;
    debug("Listening on " + bind);
}