index.js

// Module dependencies.
const app = require("./app");
const debug = require("debug")("201flaviosilva-api:server");
const http = require("http");

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

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

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


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

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

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

  return false;
}

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

  const 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() {
  const addr = server.address();
  const bind = typeof addr === "string" ? "pipe " + addr : "port " + addr.port;
  debug("Listening on " + bind);
}