Angular: Transform Resources

richResource.js

	$httpBackend.expect('GET', '/Customer/1', null).respond({
		id: 1,
		name: 'John Doe',
		age: 42,
		purchases: [
			{
				id: 1,
				items: [
					{ name: 'Shampoo' },
					{ name: 'Soap' }
				]
			}
		]
	});

	function Purchase ( p ) {
		this.id = p.id;
		this.items = p.items;
	}

	Purchase.prototype.addItem = function ( item ) {
		this.items.add({ name: 'Beer' });
	};

	var transform = function(response) {
		var model = response.model;

		angular.forEach( model.purchases , function ( purchase, i ) {
			model.purchases[i] = new Purchase( purchase );
		});

		model.hello = function () { return 'hello'; };
		return model;
	};

	var model = $model('/Customer/:id', {}, {
			get: {
				method: 'get',
				interceptor: {
					response: transform
				}
			}
		}),
		customer;

	customer = model.get({ id: 1 });
	$httpBackend.flush();
	console.log(customer.purchases[0].addItem);