index.js
function contentsAsync(file, options, cb) {
  if (typeof options === 'function') {
    cb = options;
    options = {};
  }

  if (typeof cb !== 'function') {
    throw new TypeError('expected a callback function');
  }

  if (!utils.isObject(file)) {
    cb(new TypeError('expected file to be an object'));
    return;
  }

  contentsSync(file, options);
  cb(null, file);
}
function contentsAsync(file, options, cb) {
  if (typeof options === 'function') {
    cb = options;
    options = {};
  }

  if (typeof cb !== 'function') {
    throw new TypeError('expected a callback function');
  }

  if (!utils.isObject(file)) {
    cb(new TypeError('expected file to be an object'));
    return;
  }

  contentsSync(file, options);
  cb(null, file);
}
function contentsAsync ( file , options , cb ) { if ( typeof options === 'function' ) { cb = options ; options = { } ; } if ( typeof cb !== 'function' ) { throw new TypeError ( 'expected a callback function' ) ; } if ( ! utils . isObject ( file ) ) { cb ( new TypeError ( 'expected file to be an object' ) ) ; return ; } contentsSync ( file , options ) ; cb ( null , file ) ; }
Async method for getting `file.contents`.

@param  {Object} `file`
@param  {Object} `options`
@param  {Function} `cb`
@return {Object}
Async method for getting file . contents .