next.js/packages/next/bin/next-build

#!/usr/bin/env node
import { resolve, join } from 'path'
import { existsSync } from 'fs'
import parseArgs from 'minimist'
import build from '../build'
import { printAndExit } from '../server/lib/utils'

const argv = parseArgs(process.argv.slice(2), {
  alias: {
    h: 'help',
    l: 'lambdas'
  },
  boolean: ['h', 'l']
})

if (argv.help) {
  printAndExit(`
    Description
      Compiles the application for production deployment

    Usage
      $ next build <dir>

    <dir> represents where the compiled dist folder should go.
    If no directory is provided, the dist folder will be created in the current directory.
    You can set a custom folder in config https://github.com/zeit/next.js#custom-configuration, otherwise it will be created inside '.next'
  `, 0)
}

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

// Check if pages dir exists and warn if not
if (!existsSync(dir)) {
  printAndExit(`> No such directory exists as the project root: ${dir}`)
}

if (!existsSync(join(dir, 'pages'))) {
  if (existsSync(join(dir, '..', 'pages'))) {
    printAndExit('> No `pages` directory found. Did you mean to run `next` in the parent (`../`) directory?')
  }

  printAndExit('> Couldn\'t find a `pages` directory. Please create one under the project root')
}

build(dir, null, lambdas)
  .catch((err) => {
    console.error('> Build error occured')
    printAndExit(err)
  })