Nuxt/bin/nuxt-dev

#!/usr/bin/env node

// Show logs
process.env.DEBUG = process.env.DEBUG || 'nuxt:*'

const _ = require('lodash')
const debug = require('debug')('nuxt:build')
debug.color = 2 // force green color
const fs = require('fs')
const parseArgs = require('minimist')
const { Nuxt, Builder } = require('../')
const chokidar = require('chokidar')
const resolve = require('path').resolve

const argv = parseArgs(process.argv.slice(2), {
  alias: {
    h: 'help',
    H: 'hostname',
    p: 'port',
    c: 'config-file',
    m: 'mode'
  },
  boolean: ['h'],
  string: ['H', 'c', 'm'],
  default: {
    c: 'nuxt.config.js'
  }
})

if (argv.hostname === '') {
  console.error(`> Provided hostname argument has no value`)
  process.exit(1)
}

if (argv.help) {
  console.log(`
    Description
      Starts the application in development mode (hot-code reloading, error
      reporting, etc)
    Usage
      $ nuxt dev <dir> -p <port number> -H <hostname>
    Options
      --port, -p                        A port number on which to start the application
      --hostname, -H                    Hostname on which to start the application
      --mode, -m [spa|universal|static] Nuxt Mode (default: universal)
      --config-file, -c                 Path to Nuxt.js config file (default: nuxt.config.js)
      --help, -h                        Displays this message
  `)
  process.exit(0)
}

const rootDir = resolve(argv._[0] || '.')
const nuxtConfigFile = resolve(rootDir, argv['config-file'])

// Load config once for chokidar
const nuxtConfig = loadNuxtConfig()
_.defaultsDeep(nuxtConfig, { watchers: { chokidar: { ignoreInitial: true } } })

// Start dev
let dev = startDev()

// Start watching for nuxt.config.js changes
chokidar
  .watch(nuxtConfigFile, nuxtConfig.watchers.chokidar)
  .on('all', _.debounce(() => {
    debug('[nuxt.config.js] changed')
    debug('Rebuilding the app...')
    dev = dev.then(startDev)
  }), 2500)

function startDev (oldNuxt) {
  // Get latest environment variables
  const port = argv.port || process.env.PORT || process.env.npm_package_config_nuxt_port
  const host = argv.hostname || process.env.HOST || process.env.npm_package_config_nuxt_host

  // Load options
  let options = {}
  try {
    options = loadNuxtConfig()
  } catch (err) {
    console.error(err)
    return // Wait for next reload
  }

  // Create nuxt and builder instance
  const nuxt = new Nuxt(options)
  const builder = new Builder(nuxt)

  return Promise.resolve()
    .then(() => builder.build()) // 1- Start build
    .then(() => oldNuxt ? oldNuxt.close() : Promise.resolve()) // 2- Close old nuxt after successful build
    .then(() => nuxt.listen(port, host)) // 3- Start listening
    .then(() => nuxt) // 4- Pass new nuxt to watch chain
}

function loadNuxtConfig () {
  let options = {}

  if (fs.existsSync(nuxtConfigFile)) {
    delete require.cache[nuxtConfigFile]
    options = require(nuxtConfigFile)
  } else if (argv['config-file'] !== 'nuxt.config.js') {
    console.error(`> Could not load config file ${argv['config-file']}`)
    process.exit(1)
  }

  if (typeof options.rootDir !== 'string') {
    options.rootDir = rootDir
  }

  // Force development mode for add hot reloading and watching changes
  options.dev = true

  // Nuxt Mode
  if (argv['mode']) {
    options.mode = argv['mode']
  }

  return options
}