Sort of decorator so that the Attribute class constructor function is obtainable

ng-attribute-constructor.js

angular.module('ng-attribute', [])

// Horrible hack for obtaining directive class `Attribute` constructor function.
// There is a nuisance in AngularJS in that the `constructor` property was not retained in the prototype.
.directive('attributesDecorator', function () {
	// constructor extracted from angular.js
	function Attributes(element, attributesToCopy) {
		if (attributesToCopy) {
			var keys = Object.keys(attributesToCopy);
			var i, l, key;

			for (i = 0, l = keys.length; i < l; i++) {
				key = keys[i];
				this[key] = attributesToCopy[key];
			}
		}
		else {
			this.$attr = {};
		}

		this.$$element = element;
	}

	return {
		template: function (_, attrs) {
			Attributes.prototype = Object.getPrototypeOf(attrs);
			Object.defineProperty(Attributes.prototype, 'constructor', {
				writable: true, enumerable: false, configurable: true,
				value: Attributes
			});
		}
	};
})
.run(function ($compile) {
	$compile('<attributes-decorator>');
});