compiled/src/utils.js

var la = require('lazy-ass')
var is = require('check-more-types')
var path = require('path')
var join = path.join
var fs = require('fs')

var SELF_NAME = 'compiled'

function bundleName (filename) {
  la(is.unemptyString(filename), 'expected filename', filename)
  return path.basename(filename, '.js')
}

function builtName (name) {
  la(is.unemptyString(name), 'expected name', name)
  return name + '.bundle.js'
}

function featuresName (name) {
  la(is.unemptyString(name), 'expected name', name)
  return name + '.features.json'
}

function compiledName (name) {
  la(is.unemptyString(name), 'expected name', name)
  return name + '.compiled.js'
}

function getFirstLine (filename) {
  var text = fs.readFileSync(filename, 'utf-8')
  return text.substr(0, text.indexOf('\n'))
}

function isHashbang (line) {
  return /^#!/.test(line)
}

function removeFirstLine (filename) {
  var text = fs.readFileSync(filename, 'utf-8')
  text = text.substr(text.indexOf('\n') + 1)
  fs.writeFileSync(filename, text, 'utf-8')
}

function restoreFirstLine (filename, line) {
  la(is.unemptyString(line), 'missing first line to add to', filename)
  var text = fs.readFileSync(filename, 'utf-8')
  text = line + '\n' + text
  fs.writeFileSync(filename, text, 'utf-8')
}

// TODO ends with newline could be its own small module
function endsWithNewLines (text) {
  return /\n\n$/.test(text)
}

function finishTextWithEndline (text) {
  la(is.string(text), 'expected text', text)
  if (!endsWithNewLines(text)) {
    text += '\n'
  }
  return text
}

function finishWithEndline (filename) {
  var text = fs.readFileSync(filename, 'utf-8')
  text = finishTextWithEndline(text)
  fs.writeFileSync(filename, text, 'utf-8')
}

function formFilenames (config, filename) {
  la(is.object(config), 'missing config object', config)
  la(is.unemptyString(filename), 'expected filename', filename)

  var joinDir = join.bind(null, config.dir)

  var name = bundleName(filename)
  var builtFilename = joinDir(builtName(name))
  var featuresFilename = joinDir(featuresName(name))

  var compiledFilename = is.fn(config.formOutputFilename)
    ? config.formOutputFilename(name)
    : joinDir(compiledName(name))

  return {
    built: builtFilename,
    features: featuresFilename,
    compiled: compiledFilename
  }
}

function addBabelRequire (text, moduleName) {
  text = text.trim()

  moduleName = moduleName || SELF_NAME
  var name = isSelfCompiling() ? '../src/compiled' : moduleName

  var requireLine = 'require(\'' + name + '\').babelPolyfill()\n'
  var firstNewLine = text.indexOf('\n')
  var firstLine = text.substr(0, firstNewLine + 1)

  var result

  if (/use strict/.test(firstLine)) {
    return firstLine + requireLine + text.substr(firstNewLine + 1)
  }
  if (isHashbang(firstLine)) {
    result = firstLine + '\n' + addBabelRequire(text.substr(firstNewLine + 1), moduleName)
    return result
  }
  return requireLine + text
}

function isSelfCompiling () {
  var packageFilename = join(process.cwd(), 'package.json')
  if (fs.existsSync(packageFilename)) {
    var pkg = JSON.parse(fs.readFileSync(packageFilename))
    return pkg.name === SELF_NAME
  }
}

module.exports = {
  bundleName: bundleName,
  builtName: builtName,
  featuresName: featuresName,
  compiledName: compiledName,
  getFirstLine: getFirstLine,
  isHashbang: isHashbang,
  removeFirstLine: removeFirstLine,
  restoreFirstLine: restoreFirstLine,
  finishWithEndline: finishWithEndline,
  finishTextWithEndline: finishTextWithEndline,
  formFilenames: formFilenames,
  addBabelRequire: addBabelRequire,
  isSelfCompiling: isSelfCompiling
}