next.js/bin/next-dev

#!/usr/bin/env node
import 'source-map-support/register'
import { resolve, join } from 'path'
import parseArgs from 'minimist'
import { exists } from 'mz/fs'
import Server from '../server'

const argv = parseArgs(process.argv.slice(2), {
  alias: {
    h: 'help',
    p: 'port'
  },
  boolean: ['h'],
  default: {
    p: 3000
  }
})

if (argv.help) {
  console.log(`
    Description
      Starts the application in development mode (hot-code reloading, error
      reporting, etc)

    Usage
      $ next dev <dir> -p <port number>

    <dir> represents where the compiled .next folder should go.
    If no directory is provided, .next will be created in the current directory

    Options
      --port, -p      A port number on which to start the application
      --help, -p      Displays this message
  `)
  process.exit(0)
}

const dir = resolve(argv._[0] || '.')

const srv = new Server({ dir, dev: true })
srv.start(argv.port)
.then(async () => {
  if (!process.env.NOW) {
    console.log(`> Ready on http://localhost:${argv.port}`)
  }

  // Check if pages dir exists and warn if not
  if (!(await exists(join(dir, 'pages')))) {
    if (await exists(join(dir, '..', 'pages'))) {
      console.error('> No `pages` directory found. Did you mean to run `next` in the parent (`../`) directory?')
    } else {
      console.error('> Couldn\'t find a `pages` directory. Please create one under the project root')
    }
    process.exit(1)
  }
})
.catch((err) => {
  console.error(err)
  process.exit(1)
})