webpack in gulp

gulpfile.js

/* eslint-disable no-console,import/no-dynamic-require,global-require */
const path = require('path')
const gulp = require('gulp')
const R = require('ramda')
const watch = require('gulp-watch')
const webpack = require('webpack')
const { terminal } = require('terminal-kit')

const { ProgressPlugin } = webpack
const webpackPath = './webpack.config.js'
let webpackConfig = require(webpackPath)

const progressBar = terminal.progressBar({
  width: process.env.COLUMNS,
  title: 'starting...',
  percent: true,
  inline: true,
  titleSize: 75,
})

const progressPlugin = new ProgressPlugin((percentage, message, ...args) => {
  progressBar.update({ progress: percentage, title: `${message} ${args.join(' ')}` })
})
const statConfig = {
  chunks: true,
  chunkModules: false,
  colors: true,
  modules: false,
  children: true,
}
const watcher = from => {
  from.watch({
    ignored: /node_modules/,
  }, (err, stats) => {
    if (err) {
      console.error(err.stack || err)
      if (err.details) {
        console.error(err.details)
      }
      return
    }

    console.log(stats.toString(statConfig))
    const info = stats.toJson()

    if (stats.hasWarnings()) {
      console.warn(info.warnings)
    }
    if (stats.hasErrors()) {
      console.error(info.errors)
    }
  })
}

const compiler = config => {
  const c = [].concat(config)
  return webpack(R.map(R.over(R.lensPath(['plugins']), R.concat([progressPlugin])), c))
}

gulp.task('start', (cb) => {
  let instance = watcher(compiler(webpackConfig))
  // watch('./dist', () => { /* node ./dist/index.js */ })
  watch([webpackPath], () => {
    console.log('loading new webpack config')
    delete require.cache[path.resolve(webpackPath)]
    webpackConfig = require(webpackPath).default
    instance.close(() => {
      instance = watcher(compiler(webpackConfig))
    })
  })
})

gulp.task('build', cb => {
  compiler(webpackConfig).run((err, stats) => {
    if (err) console.error(err)
    console.log(stats.toString(statConfig))
    cb()
  })
})

gulp.task('default', ['start'])