eluck-demopack/lib/create-compiler.js

Easily build front end projects.

const webpack = require('webpack')
const WebpackDevServer = require('webpack-dev-server')
const {
  choosePort,
  prepareUrls,
  prepareProxy,
} = require('react-dev-utils/WebpackDevServerUtils')
const formatWebpackMessages = require('react-dev-utils/formatWebpackMessages')
const clearConsole = require('react-dev-utils/clearConsole')
const openBrowser = require('react-dev-utils/openBrowser')
const chalk = require('chalk')
const printInstructions = require('./print-instructions')

const isInteractive = process.stdout.isTTY

module.exports = (webpack, config, appName, urls) => {
  // "Compiler" is a low-level interface to Webpack.
  // It lets us listen to some events and provide our own custom messages.
  let compiler
  try {
    compiler = webpack(config)
  } catch (err) {
    console.log(chalk.red('Failed to compile.'))
    console.log()
    console.log(err.message || err)
    console.log()
    process.exit(1)
  }

  // "invalid" event fires when you have changed a file, and Webpack is
  // recompiling a bundle. WebpackDevServer takes care to pause serving the
  // bundle, so if you refresh, it'll wait instead of serving the old one.
  // "invalid" is short for "bundle invalidated", it doesn't imply any errors.
  compiler.plugin('invalid', () => {
    if (isInteractive) {
      clearConsole()
    }
    console.log('Compiling...')
  })

  let isFirstCompile = true

  // "done" event fires when Webpack has finished recompiling the bundle.
  // Whether or not you have warnings or errors, you will get this event.
  compiler.plugin('done', stats => {
    if (isInteractive) {
      clearConsole()
    }

    // We have switched off the default Webpack output in WebpackDevServer
    // options so we are going to "massage" the warnings and errors and present
    // them in a readable focused way.
    const messages = formatWebpackMessages(stats.toJson({}, true))

    const isSuccessful = !messages.errors.length && !messages.warnings.length
    if (isSuccessful) {
      console.log(chalk.green('Compiled successfully!'))
    }
    if (isSuccessful && (isInteractive || isFirstCompile)) {
      printInstructions(appName, urls)
    }
    isFirstCompile = false

    // If errors exist, only show errors.
    if (messages.errors.length) {
      console.log(chalk.red('Failed to compile.\n'))
      console.log(messages.errors.join('\n\n'))
      return
    }

    // Show warnings if no errors were found.
    if (messages.warnings.length) {
      console.log(chalk.yellow('Compiled with warnings.\n'))
      console.log(messages.warnings.join('\n\n'))
    }
  })
  return compiler
}