poor man's sprockets (async)

node-sprockets-async

#!/usr/bin/env node

var crypto = require('crypto')
var path = require('path')
var fs = require('fs')
var Promise = require('bluebird')
Promise.promisifyAll(fs)

function hash(input, algorithm, encoding) {
  return crypto
    .createHash(algorithm || 'md5')
    .update(input, 'utf8')
    .digest(encoding || 'hex')
}

var assetMap = {}
var assetMapFileDir = null

Promise.map(process.argv.slice(2), function(filearg) {
  var file = path.relative(process.cwd(), filearg)
  var fileDir = path.dirname(file)
  var fileExt = path.extname(file)

  if (!assetMapFileDir) assetMapFileDir = fileDir

  return fs.readFileAsync(file)
    .then(function(fileContents) {
      var digest = hash(fileContents)
      assetMap[file] = path.join(fileDir, path.basename(file, fileExt)+'-'+digest.slice(0, 8)+fileExt)

      return fs.writeFileAsync(assetMap[file], fileContents)
    })
})
  .then(function() {
    return fs.writeFileAsync(
      path.join(assetMapFileDir, 'assets.json'),
      JSON.stringify(assetMap, null, 2)
    )
  })
  .then(function() {
    process.exit(0)
  })