vue-cli/packages/@vue/cli-shared-utils/index.js

const chalk = require('chalk')
const padStart = require('string.prototype.padstart')

const format = (label, msg) => {
  return msg.split('\n').map((line, i) => {
    return i === 0
      ? `${label} ${line}`
      : padStart(line, chalk.reset(label).length)
  }).join('\n')
}

exports.info = msg => {
  console.log(format(chalk.bgBlue.black(' INFO '), msg))
}

exports.success = msg => {
  console.log(format(chalk.bgGreen.black('  OK  '), msg))
}

exports.warn = msg => {
  console.warn(format(chalk.bgYellow.black(' WARN '), chalk.yellow(msg)))
}

exports.error = (msg) => {
  console.error(format(chalk.bgRed(' ERROR '), chalk.red(msg)))
  if (msg instanceof Error) {
    console.error(msg.stack)
  }
}

const cliVersion = require('@vue/cli/package.json').version
exports.clearConsole = function () {
  if (process.stdout.isTTY) {
    process.stdout.write(
      process.platform === 'win32' ? '\x1Bc' : '\x1B[2J\x1B[3J\x1B[H'
    )
    let title = chalk.bold.green(`Vue CLI v${cliVersion}`)
    if (process.env.VUE_CLI_DEBUG) {
      title += ' ' + chalk.bgRed(' DEBUG MODE ')
    }
    console.log(title)
    console.log()
  }
}

exports.hasYarn = (() => {
  try {
    require('child_process').execSync('yarnpkg --version', { stdio: 'ignore' })
    return true
  } catch (e) {
    return false
  }
})()