Function mergeAssets

01.GettingStarted/js/vue.js:1728–1731

* Assets * * When a vm is present (instance creation), we need to do * a three-way merge between constructor options, instance * options and parent options.

(parentVal, childVal)

   */

  function mergeAssets(parentVal, childVal) {
    var res = Object.create(parentVal || null);
    return childVal ? extend(res, guardArrayAssets(childVal)) : res;
  }

  config._assetTypes.forEach(function (type) {
    strats[type + 's'] = mergeAssets;