code: function size(file) {
    if (!exists(file) || !isFile(file)) {
      return -1;
    } else {
      try {
        return _fileStats(file).size;
      } catch (e) {
        return -1;
      }
    }
  }
docs: Returns the size of a given path. Returns -1 if the path is a directory or does not exists.
  @function $file~size
  @param {string} file
  @returns {number}
  @example
  // Get file size of '/bin/ls'
  $file.size('/bin/ls');
  // => 110080