Function getPropDefaultValue

06.Router/basic/js/vue.js:6224–6238

* Get the default value of a prop. * * @param {Vue} vm * @param {Object} prop * @return {*}

(vm, prop)

   */

  function getPropDefaultValue(vm, prop) {
    // no default, return undefined
    var options = prop.options;
    if (!hasOwn(options, 'default')) {
      // absent boolean value defaults to false
      return options.type === Boolean ? false : undefined;
    }
    var def = options['default'];
    // warn against non-factory defaults for Object & Array
    if (isObject(def)) {
      'development' !== 'production' && warn('Invalid default value for prop "' + prop.name + '": ' + 'Props with type Object/Array must use a factory function ' + 'to return the default value.', vm);
    }
    // call factory function for non-Function types
    return typeof def === 'function' && options.type !== Function ? def.call(vm) : def;
  }

  /**
   * Assert whether a prop is valid.