old_contents: 'use strict'
  
  var SOL_CACHE_FILE_PREFIX = 'sol-cache-file-'
  
  function getCacheFilePrefix () {
    return SOL_CACHE_FILE_PREFIX
  }
  
  function isCachedFile (name) {
    return name.indexOf(getCacheFilePrefix(), 0) === 0
  }
  
  function fileKey (name) {
    return getCacheFilePrefix() + name
  }
  
  function fileNameFromKey (key) {
    return key.replace(getCacheFilePrefix(), '')
  }
  
  function errortype (message) {
    return message.match(/^.*:[0-9]*:[0-9]* Warning: /) ? 'warning' : 'error'
  }
  
  module.exports = {
    isCachedFile: isCachedFile,
    fileKey: fileKey,
    fileNameFromKey: fileNameFromKey,
    errortype: errortype
  }
  
new_contents: 'use strict'
  
  var SOL_CACHE_FILE_PREFIX = 'sol-cache-file-'
  
  function getCacheFilePrefix () {
    return SOL_CACHE_FILE_PREFIX
  }
  
  function isCachedFile (name) {
    return name.indexOf(getCacheFilePrefix(), 0) === 0
  }
  
  function fileKey (name) {
    return getCacheFilePrefix() + name
  }
  
  function fileNameFromKey (key) {
    return key.replace(getCacheFilePrefix(), '')
  }
  
  function errortype (message) {
    return message.match(/^(.*:[0-9]*:[0-9]* )?Warning: /) ? 'warning' : 'error'
  }
  
  module.exports = {
    isCachedFile: isCachedFile,
    fileKey: fileKey,
    fileNameFromKey: fileNameFromKey,
    errortype: errortype
  }
  
subject: Fix warning detection.