Inserts colons to stylus code

insert-colons-to-my-styl-please.js

var fs = require('fs')
  , filesToCorrect = process.argv.length - 2
  , addColonsToFile = function (pathToFile) {
  try {
    var code = fs.readFileSync(pathToFile).toString()
      , stringsToReplace = code.match(/^\s*(?!for)([a-z-]*)\b\s+[^:=]/gm)
  } catch(e) {
      console.log('error while reading: ' + pathToFile)
  }
  if (stringsToReplace === null) return
  stringsToReplace.forEach(function(stringToReplace) {
    var newString = stringToReplace.replace(/^\s*([a-z-]*)\b/,
      stringToReplace.match(/^\s*[a-z-]*\b/) + ':' )
    code = code.replace(stringToReplace, newString)
  })
  fs.writeFileSync(pathToFile, code)
  console.log('completed: ' + pathToFile + ', with ' + stringsToReplace.length +' rows affected')
}

if (filesToCorrect !== 0)
  while(filesToCorrect--)
    addColonsToFile(process.argv[filesToCorrect + 2])

Run tool:
node insert-colons-to-my-styl-please.js ./*.styl

I would recommend replacing the stringsToReplace regex with /^\s*(?!for)([a-z-]*)\b[ \t]+[^:=\n]/gm to account for tag selectors such as

a
    font-size 1