index.js
function processFileByModifiedTime(stream, firstPass, basePath, file, cache) {
  var newTime = file.stat && file.stat.mtime;
  var filePath = basePath ? path.relative(basePath, file.path) : file.path;
  var oldTime = cache[filePath];

  cache[filePath] = newTime.getTime();

  if ((!oldTime && firstPass) || (oldTime && oldTime !== newTime.getTime())) {
    stream.push(file);
  }
}
function processFileByModifiedTime(stream, firstPass, basePath, file, cache) {
  var newTime = file.stat && file.stat.mtime;
  var filePath = basePath ? path.relative(basePath, file.path) : file.path;
  var oldTime = cache[filePath];

  cache[filePath] = newTime.getTime();

  if ((!oldTime && firstPass) || (oldTime && oldTime !== newTime.getTime())) {
    stream.push(file);
  }
}
function processFileByModifiedTime ( stream , firstPass , basePath , file , cache ) { var newTime = file . stat && file . stat . mtime ; var filePath = basePath ? path . relative ( basePath , file . path ) : file . path ; var oldTime = cache [ filePath ] ; cache [ filePath ] = newTime . getTime ( ) ; if ( ( ! oldTime && firstPass ) || ( oldTime && oldTime !== newTime . getTime ( ) ) ) { stream . push ( file ) ; } }
look for changes by mtime
look for changes by mtime