server.js

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var methodOverride = require('method-override');

var index = require('./routes/index');
var api = require('./routes/api');

// In Heroku, $PORT environment is set.
//   ref. https://github.com/heroku/node-js-getting-started/blob/787a0397af4e2a295607cced85aa882931c18d3d/index.js#L3
var port = process.env.PORT || 3000

var server = express();

// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
server.use(logger('dev'));
server.use(bodyParser.json());
server.use(bodyParser.urlencoded({ extended: false }));
server.use(cookieParser());

// override HTTP method to using CRUD
server.use(methodOverride('_method'));

// allow CORS
//   see. https://developer.mozilla.org/ja/docs/Web/HTTP/HTTP_access_control
server.use(function(req, res, next) {
  res.header("Access-Control-Allow-Origin", "*");
  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
  next();
});

server.use('/_api/', api);

// correspond Express and React
server.use(express.static(path.join(__dirname, 'build')));
server.get('/*', function(req, res) {
  res.sendFile(path.join(__dirname, 'build', 'index.html'));
});

// catch 404 and forward to error handler
server.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

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

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

server.get('*', (req, res) => {
  return handle(req, res);
})

server.listen(port, (err) => {
  if (err) throw err
  console.log(`> Ready on http://localhost:${port}`)
})

module.exports = server;