brunch proxied dev server

dev_server.js

// 1. npm i -D express http-proxy
// 2. add to config: "server: { path: 'dev_server' }"
const express = require('express')
const sysPath = require('path')
const http = require('http')
const httpProxy = require('http-proxy')

const apiProxy = httpProxy.createServer({
  target: 'http://localhost:3000'
})

// https://github.com/brunch/brunch-guide/blob/master/content/en/chapter10-web-server.md
exports.startServer = function (port, path, done) {
  const app = express()

  app.use(express['static'](path))

  app.all('/api/*', (req, res) => {
    return apiProxy.web(req, res)
  })

  app.all('/*', (req, res) => {
    return res.sendFile(sysPath.resolve(sysPath.join(path, 'index.html')))
  })

  server = http.createServer(app)
  server.listen(parseInt(port, 10), done)

  return server
}