angular-cn/modules/angular2/test/change_detection/differs/iterable_differs_spec.ts

import {
  ddescribe,
  describe,
  it,
  iit,
  xit,
  expect,
  beforeEach,
  afterEach,
  SpyIterableDifferFactory
} from 'angular2/test_lib';
import {IterableDiffers} from 'angular2/src/change_detection/differs/iterable_differs';
import {Injector, bind} from 'angular2/di';

export function main() {
  describe('IterableDiffers', function() {
    var factory1;
    var factory2;
    var factory3;

    beforeEach(() => {
      factory1 = new SpyIterableDifferFactory();
      factory2 = new SpyIterableDifferFactory();
      factory3 = new SpyIterableDifferFactory();
    });

    it('should throw when no suitable implementation found', () => {
      var differs = new IterableDiffers([]);
      expect(() => differs.find("some object"))
          .toThrowErrorWith("Cannot find a differ supporting object 'some object'")
    });

    it('should return the first suitable implementation', () => {
      factory1.spy("supports").andReturn(false);
      factory2.spy("supports").andReturn(true);
      factory3.spy("supports").andReturn(true);

      var differs = IterableDiffers.create(<any>[factory1, factory2, factory3]);
      expect(differs.find("some object")).toBe(factory2);
    });

    it('should copy over differs from the parent repo', () => {
      factory1.spy("supports").andReturn(true);
      factory2.spy("supports").andReturn(false);

      var parent = IterableDiffers.create(<any>[factory1]);
      var child = IterableDiffers.create(<any>[factory2], parent);

      expect(child.factories).toEqual([factory2, factory1]);
    });

    describe(".extend()", () => {
      it('should throw if calling extend when creating root injector', () => {
        var injector = Injector.resolveAndCreate([IterableDiffers.extend([])]);

        expect(() => injector.get(IterableDiffers))
            .toThrowErrorWith("Cannot extend IterableDiffers without a parent injector");
      });

      it('should extend di-inherited diffesr', () => {
        var parent = new IterableDiffers([factory1]);
        var injector = Injector.resolveAndCreate([bind(IterableDiffers).toValue(parent)]);
        var childInjector = injector.resolveAndCreateChild([IterableDiffers.extend([factory2])]);

        expect(injector.get(IterableDiffers).factories).toEqual([factory1]);
        expect(childInjector.get(IterableDiffers).factories).toEqual([factory2, factory1]);
      });
    });
  });
}