angular-cn/packages/upgrade/test/static/integration/downgrade_module_spec.ts

/**
 * @license
 * Copyright Google Inc. All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import {AfterContentChecked, AfterContentInit, AfterViewChecked, AfterViewInit, ApplicationRef, Compiler, Component, Directive, DoCheck, ElementRef, Inject, Injectable, Injector, Input, NgModule, NgZone, OnChanges, OnDestroy, OnInit, StaticProvider, Type, ViewRef, destroyPlatform, getPlatform} from '@angular/core';
import {async, fakeAsync, tick} from '@angular/core/testing';
import {BrowserModule} from '@angular/platform-browser';
import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
import {browserDetection} from '@angular/platform-browser/testing/src/browser_util';
import {fixmeIvy} from '@angular/private/testing';
import {UpgradeComponent, downgradeComponent, downgradeModule} from '@angular/upgrade/static';
import * as angular from '@angular/upgrade/static/src/common/angular1';
import {$EXCEPTION_HANDLER, $ROOT_SCOPE, INJECTOR_KEY, LAZY_MODULE_REF} from '@angular/upgrade/static/src/common/constants';
import {LazyModuleRef} from '@angular/upgrade/static/src/common/util';
import {setTempInjectorRef} from '@angular/upgrade/static/src/static/angular1_providers';

import {html, multiTrim, withEachNg1Version} from '../test_helpers';


withEachNg1Version(() => {
  [true, false].forEach(propagateDigest => {
    describe(`lazy-load ng2 module (propagateDigest: ${propagateDigest})`, () => {

      beforeEach(() => destroyPlatform());
      afterEach(() => destroyPlatform());

      it('should support multiple downgraded modules', async(() => {
           @Component({selector: 'ng2A', template: 'a'})
           class Ng2ComponentA {
           }

           @Component({selector: 'ng2B', template: 'b'})
           class Ng2ComponentB {
           }

           @NgModule({
             declarations: [Ng2ComponentA],
             entryComponents: [Ng2ComponentA],
             imports: [BrowserModule],
           })
           class Ng2ModuleA {
             ngDoBootstrap() {}
           }

           @NgModule({
             declarations: [Ng2ComponentB],
             entryComponents: [Ng2ComponentB],
             imports: [BrowserModule],
           })
           class Ng2ModuleB {
             ngDoBootstrap() {}
           }

           const doDowngradeModule = (module: Type<any>) => {
             const bootstrapFn = (extraProviders: StaticProvider[]) =>
                 (getPlatform() || platformBrowserDynamic(extraProviders)).bootstrapModule(module);
             return downgradeModule(bootstrapFn);
           };

           const downModA = doDowngradeModule(Ng2ModuleA);
           const downModB = doDowngradeModule(Ng2ModuleB);
           const ng1Module = angular.module('ng1', [downModA, downModB])
                                 .directive('ng2A', downgradeComponent({
                                              component: Ng2ComponentA,
                                              downgradedModule: downModA, propagateDigest,
                                            }))
                                 .directive('ng2B', downgradeComponent({
                                              component: Ng2ComponentB,
                                              downgradedModule: downModB, propagateDigest,
                                            }));

           const element = html('<ng2-a></ng2-a> | <ng2-b></ng2-b>');
           angular.bootstrap(element, [ng1Module.name]);

           // Wait for the module to be bootstrapped.
           setTimeout(() => expect(element.textContent).toBe('a | b'));
         }));

      it('should support nesting components from different downgraded modules', async(() => {
           @Directive({selector: 'ng1A'})
           class Ng1ComponentA extends UpgradeComponent {
             constructor(elementRef: ElementRef, injector: Injector) {
               super('ng1A', elementRef, injector);
             }
           }

           @Component({
             selector: 'ng2A',
             template: 'ng2A(<ng1A></ng1A>)',
           })
           class Ng2ComponentA {
           }

           @Component({
             selector: 'ng2B',
             template: 'ng2B',
           })
           class Ng2ComponentB {
           }

           @NgModule({
             declarations: [Ng1ComponentA, Ng2ComponentA],
             entryComponents: [Ng2ComponentA],
             imports: [BrowserModule],
           })
           class Ng2ModuleA {
             ngDoBootstrap() {}
           }

           @NgModule({
             declarations: [Ng2ComponentB],
             entryComponents: [Ng2ComponentB],
             imports: [BrowserModule],
           })
           class Ng2ModuleB {
             ngDoBootstrap() {}
           }

           const doDowngradeModule = (module: Type<any>) => {
             const bootstrapFn = (extraProviders: StaticProvider[]) => {
               const platformRef = getPlatform() || platformBrowserDynamic(extraProviders);
               return platformRef.bootstrapModule(module);
             };
             return downgradeModule(bootstrapFn);
           };

           const downModA = doDowngradeModule(Ng2ModuleA);
           const downModB = doDowngradeModule(Ng2ModuleB);
           const ng1Module =
               angular.module('ng1', [downModA, downModB])
                   .directive('ng1A', () => ({template: 'ng1A(<ng2-b ng-if="showB"></ng2-b>)'}))
                   .directive('ng2A', downgradeComponent({
                                component: Ng2ComponentA,
                                downgradedModule: downModA, propagateDigest,
                              }))
                   .directive('ng2B', downgradeComponent({
                                component: Ng2ComponentB,
                                downgradedModule: downModB, propagateDigest,
                              }));

           const element = html('<ng2-a></ng2-a>');
           const $injector = angular.bootstrap(element, [ng1Module.name]);
           const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

           // Wait for module A to be bootstrapped.
           setTimeout(() => {
             // Wait for the upgraded component's `ngOnInit()`.
             setTimeout(() => {
               expect(element.textContent).toBe('ng2A(ng1A())');

               $rootScope.$apply('showB = true');

               // Wait for module B to be bootstrapped.
               setTimeout(() => expect(element.textContent).toBe('ng2A(ng1A(ng2B))'));
             });
           });
         }));

      it('should support nesting components from different downgraded modules (via projection)',
         async(() => {
           @Component({
             selector: 'ng2A',
             template: 'ng2A(<ng-content></ng-content>)',
           })
           class Ng2ComponentA {
           }

           @Component({
             selector: 'ng2B',
             template: 'ng2B',
           })
           class Ng2ComponentB {
           }

           @NgModule({
             declarations: [Ng2ComponentA],
             entryComponents: [Ng2ComponentA],
             imports: [BrowserModule],
           })
           class Ng2ModuleA {
             ngDoBootstrap() {}
           }

           @NgModule({
             declarations: [Ng2ComponentB],
             entryComponents: [Ng2ComponentB],
             imports: [BrowserModule],
           })
           class Ng2ModuleB {
             ngDoBootstrap() {}
           }

           const doDowngradeModule = (module: Type<any>) => {
             const bootstrapFn = (extraProviders: StaticProvider[]) => {
               const platformRef = getPlatform() || platformBrowserDynamic(extraProviders);
               return platformRef.bootstrapModule(module);
             };
             return downgradeModule(bootstrapFn);
           };

           const downModA = doDowngradeModule(Ng2ModuleA);
           const downModB = doDowngradeModule(Ng2ModuleB);
           const ng1Module = angular.module('ng1', [downModA, downModB])
                                 .directive('ng2A', downgradeComponent({
                                              component: Ng2ComponentA,
                                              downgradedModule: downModA, propagateDigest,
                                            }))
                                 .directive('ng2B', downgradeComponent({
                                              component: Ng2ComponentB,
                                              downgradedModule: downModB, propagateDigest,
                                            }));

           const element = html('<ng2-a><ng2-b ng-if="showB"></ng2-b></ng2-a>');
           const $injector = angular.bootstrap(element, [ng1Module.name]);
           const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

           // Wait for module A to be bootstrapped.
           setTimeout(() => {
             expect(element.textContent).toBe('ng2A()');

             $rootScope.$apply('showB = true');

             // Wait for module B to be bootstrapped.
             setTimeout(() => expect(element.textContent).toBe('ng2A(ng2B)'));
           });
         }));

      it('should support manually setting up a root module for all downgraded modules',
         fakeAsync(() => {
           @Injectable({providedIn: 'root'})
           class CounterService {
             private static counter = 0;
             value = ++CounterService.counter;
           }

           @Component({
             selector: 'ng2A',
             template: 'ng2A(Counter:{{ counter.value }} | <ng-content></ng-content>)',
           })
           class Ng2ComponentA {
             constructor(public counter: CounterService) {}
           }

           @Component({
             selector: 'ng2B',
             template: 'Counter:{{ counter.value }}',
           })
           class Ng2ComponentB {
             constructor(public counter: CounterService) {}
           }

           @NgModule({
             declarations: [Ng2ComponentA],
             entryComponents: [Ng2ComponentA],
           })
           class Ng2ModuleA {
           }

           @NgModule({
             declarations: [Ng2ComponentB],
             entryComponents: [Ng2ComponentB],
           })
           class Ng2ModuleB {
           }

           // "Empty" module that will serve as root for all downgraded modules,
           // ensuring there will only be one instance for all injectables provided in "root".
           @NgModule({
             imports: [BrowserModule],
           })
           class Ng2ModuleRoot {
             ngDoBootstrap() {}
           }

           let rootInjectorPromise: Promise<Injector>|null = null;
           const doDowngradeModule = (module: Type<any>) => {
             const bootstrapFn = (extraProviders: StaticProvider[]) => {
               if (!rootInjectorPromise) {
                 rootInjectorPromise = platformBrowserDynamic(extraProviders)
                                           .bootstrapModule(Ng2ModuleRoot)
                                           .then(ref => ref.injector);
               }

               return rootInjectorPromise.then(rootInjector => {
                 const compiler = rootInjector.get(Compiler);
                 const moduleFactory = compiler.compileModuleSync(module);

                 return moduleFactory.create(rootInjector);
               });
             };
             return downgradeModule(bootstrapFn);
           };

           const downModA = doDowngradeModule(Ng2ModuleA);
           const downModB = doDowngradeModule(Ng2ModuleB);
           const ng1Module = angular.module('ng1', [downModA, downModB])
                                 .directive('ng2A', downgradeComponent({
                                              component: Ng2ComponentA,
                                              downgradedModule: downModA, propagateDigest,
                                            }))
                                 .directive('ng2B', downgradeComponent({
                                              component: Ng2ComponentB,
                                              downgradedModule: downModB, propagateDigest,
                                            }));

           const element = html(`
              <ng2-a><ng2-b ng-if="showB1"></ng2-b></ng2-a>
              <ng2-b ng-if="showB2"></ng2-b>
            `);
           const $injector = angular.bootstrap(element, [ng1Module.name]);
           const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

           tick();  // Wait for module A to be bootstrapped.
           expect(multiTrim(element.textContent)).toBe('ng2A(Counter:1 | )');

           // Nested component B should use the same `CounterService` instance.
           $rootScope.$apply('showB1 = true');

           tick();  // Wait for module B to be bootstrapped.
           expect(multiTrim(element.children[0].textContent)).toBe('ng2A(Counter:1 | Counter:1)');

           // Top-level component B should use the same `CounterService` instance.
           $rootScope.$apply('showB2 = true');
           tick();

           expect(multiTrim(element.children[1].textContent)).toBe('Counter:1');
         }));

      fixmeIvy('FW-873: projected component injector hierarchy not wired up correctly')
          .it('should correctly traverse the injector tree of downgraded components', async(() => {
                @Component({
                  selector: 'ng2A',
                  template: 'ng2A(<ng-content></ng-content>)',
                  providers: [
                    {provide: 'FOO', useValue: 'CompA-foo'},
                    {provide: 'BAR', useValue: 'CompA-bar'},
                  ],
                })
                class Ng2ComponentA {
                }

                @Component({
                  selector: 'ng2B',
                  template: `
               FOO:{{ foo }}
               BAR:{{ bar }}
               BAZ:{{ baz }}
               QUX:{{ qux }}
             `,
                  providers: [
                    {provide: 'FOO', useValue: 'CompB-foo'},
                  ],
                })
                class Ng2ComponentB {
                  constructor(
                      @Inject('FOO') public foo: string, @Inject('BAR') public bar: string,
                      @Inject('BAZ') public baz: string, @Inject('QUX') public qux: string) {}
                }

                @NgModule({
                  declarations: [Ng2ComponentA, Ng2ComponentB],
                  entryComponents: [Ng2ComponentA, Ng2ComponentB],
                  imports: [BrowserModule],
                  providers: [
                    {provide: 'FOO', useValue: 'Mod-foo'},
                    {provide: 'BAR', useValue: 'Mod-bar'},
                    {provide: 'BAZ', useValue: 'Mod-baz'},
                  ],
                })
                class Ng2Module {
                  ngDoBootstrap() {}
                }

                const bootstrapFn = (extraProviders: StaticProvider[]) => {
                  const platformRef = getPlatform() || platformBrowserDynamic([
                                        ...extraProviders,
                                        {provide: 'FOO', useValue: 'Plat-foo'},
                                        {provide: 'BAR', useValue: 'Plat-bar'},
                                        {provide: 'BAZ', useValue: 'Plat-baz'},
                                        {provide: 'QUX', useValue: 'Plat-qux'},
                                      ]);
                  return platformRef.bootstrapModule(Ng2Module);
                };

                const downMod = downgradeModule(bootstrapFn);
                const ng1Module =
                    angular.module('ng1', [downMod])
                        .directive(
                            'ng2A', downgradeComponent({component: Ng2ComponentA, propagateDigest}))
                        .directive(
                            'ng2B',
                            downgradeComponent({component: Ng2ComponentB, propagateDigest}));

                const element = html(`
              <ng2-a><ng2-b ng-if="showB1"></ng2-b></ng2-a>
              <ng2-b ng-if="showB2"></ng2-b>
            `);
                const $injector = angular.bootstrap(element, [ng1Module.name]);
                const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

                // Wait for the module to be bootstrapped.
                setTimeout(() => {
                  expect(multiTrim(element.textContent)).toBe('ng2A()');

                  // Nested component B.
                  $rootScope.$apply('showB1 = true');
                  expect(multiTrim(element.children[0].textContent))
                      .toBe('ng2A( FOO:CompB-foo BAR:CompA-bar BAZ:Mod-baz QUX:Plat-qux )');

                  // Standalone component B.
                  $rootScope.$apply('showB2 = true');
                  expect(multiTrim(element.children[1].textContent))
                      .toBe('FOO:CompB-foo BAR:Mod-bar BAZ:Mod-baz QUX:Plat-qux');
                });
              }));

      fixmeIvy('FW-873: projected component injector hierarchy not wired up correctly')
          .it('should correctly traverse the injector tree of downgraded components (from different modules)',
              async(() => {
                @Component({
                  selector: 'ng2A',
                  template: 'ng2A(<ng-content></ng-content>)',
                  providers: [
                    {provide: 'FOO', useValue: 'CompA-foo'},
                    {provide: 'BAR', useValue: 'CompA-bar'},
                  ],
                })
                class Ng2ComponentA {
                }

                @Component({
                  selector: 'ng2B',
                  template: `
               FOO:{{ foo }}
               BAR:{{ bar }}
               BAZ:{{ baz }}
               QUX:{{ qux }}
               QUUX:{{ quux }}
             `,
                  providers: [
                    {provide: 'FOO', useValue: 'CompB-foo'},
                  ],
                })
                class Ng2ComponentB {
                  constructor(
                      @Inject('FOO') public foo: string, @Inject('BAR') public bar: string,
                      @Inject('BAZ') public baz: string, @Inject('QUX') public qux: string,
                      @Inject('QUUX') public quux: string) {}
                }

                @NgModule({
                  declarations: [Ng2ComponentA],
                  entryComponents: [Ng2ComponentA],
                  imports: [BrowserModule],
                  providers: [
                    {provide: 'FOO', useValue: 'ModA-foo'},
                    {provide: 'BAR', useValue: 'ModA-bar'},
                    {provide: 'BAZ', useValue: 'ModA-baz'},
                    {provide: 'QUX', useValue: 'ModA-qux'},
                  ],
                })
                class Ng2ModuleA {
                  ngDoBootstrap() {}
                }

                @NgModule({
                  declarations: [Ng2ComponentB],
                  entryComponents: [Ng2ComponentB],
                  imports: [BrowserModule],
                  providers: [
                    {provide: 'FOO', useValue: 'ModB-foo'},
                    {provide: 'BAR', useValue: 'ModB-bar'},
                    {provide: 'BAZ', useValue: 'ModB-baz'},
                  ],
                })
                class Ng2ModuleB {
                  ngDoBootstrap() {}
                }

                const doDowngradeModule = (module: Type<any>) => {
                  const bootstrapFn = (extraProviders: StaticProvider[]) => {
                    const platformRef = getPlatform() || platformBrowserDynamic([
                                          ...extraProviders,
                                          {provide: 'FOO', useValue: 'Plat-foo'},
                                          {provide: 'BAR', useValue: 'Plat-bar'},
                                          {provide: 'BAZ', useValue: 'Plat-baz'},
                                          {provide: 'QUX', useValue: 'Plat-qux'},
                                          {provide: 'QUUX', useValue: 'Plat-quux'},
                                        ]);
                    return platformRef.bootstrapModule(module);
                  };
                  return downgradeModule(bootstrapFn);
                };

                const downModA = doDowngradeModule(Ng2ModuleA);
                const downModB = doDowngradeModule(Ng2ModuleB);
                const ng1Module = angular.module('ng1', [downModA, downModB])
                                      .directive('ng2A', downgradeComponent({
                                                   component: Ng2ComponentA,
                                                   downgradedModule: downModA, propagateDigest,
                                                 }))
                                      .directive('ng2B', downgradeComponent({
                                                   component: Ng2ComponentB,
                                                   downgradedModule: downModB, propagateDigest,
                                                 }));

                const element = html(`
              <ng2-a><ng2-b ng-if="showB1"></ng2-b></ng2-a>
              <ng2-b ng-if="showB2"></ng2-b>
            `);
                const $injector = angular.bootstrap(element, [ng1Module.name]);
                const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

                // Wait for module A to be bootstrapped.
                setTimeout(() => {
                  expect(multiTrim(element.textContent)).toBe('ng2A()');

                  // Nested component B.
                  $rootScope.$apply('showB1 = true');

                  // Wait for module B to be bootstrapped.
                  setTimeout(() => {
                    // It is debatable, whether the order of traversal should be:
                    // CompB > CompA > ModB > ModA > Plat (similar to how lazy-loaded components
                    // work)
                    expect(multiTrim(element.children[0].textContent))
                        .toBe(
                            'ng2A( FOO:CompB-foo BAR:CompA-bar BAZ:ModB-baz QUX:Plat-qux QUUX:Plat-quux )');

                    // Standalone component B.
                    $rootScope.$apply('showB2 = true');
                    expect(multiTrim(element.children[1].textContent))
                        .toBe(
                            'FOO:CompB-foo BAR:ModB-bar BAZ:ModB-baz QUX:Plat-qux QUUX:Plat-quux');
                  });
                });
              }));

      it('should support downgrading a component and propagate inputs', async(() => {
           @Component(
               {selector: 'ng2A', template: 'a({{ value }}) | <ng2B [value]="value"></ng2B>'})
           class Ng2AComponent {
             @Input() value = -1;
           }

           @Component({selector: 'ng2B', template: 'b({{ value }})'})
           class Ng2BComponent {
             @Input() value = -2;
           }

           @NgModule({
             declarations: [Ng2AComponent, Ng2BComponent],
             entryComponents: [Ng2AComponent],
             imports: [BrowserModule],
           })
           class Ng2Module {
             ngDoBootstrap() {}
           }

           const bootstrapFn = (extraProviders: StaticProvider[]) =>
               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
           const ng1Module =
               angular.module('ng1', [lazyModuleName])
                   .directive(
                       'ng2', downgradeComponent({component: Ng2AComponent, propagateDigest}))
                   .run(($rootScope: angular.IRootScopeService) => $rootScope.value = 0);

           const element = html('<div><ng2 [value]="value" ng-if="loadNg2"></ng2></div>');
           const $injector = angular.bootstrap(element, [ng1Module.name]);
           const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

           expect(element.textContent).toBe('');
           expect(() => $injector.get(INJECTOR_KEY)).toThrowError();

           $rootScope.$apply('value = 1');
           expect(element.textContent).toBe('');
           expect(() => $injector.get(INJECTOR_KEY)).toThrowError();

           $rootScope.$apply('loadNg2 = true');
           expect(element.textContent).toBe('');
           expect(() => $injector.get(INJECTOR_KEY)).toThrowError();

           // Wait for the module to be bootstrapped.
           setTimeout(() => {
             expect(() => $injector.get(INJECTOR_KEY)).not.toThrow();

             // Wait for `$evalAsync()` to propagate inputs.
             setTimeout(() => expect(element.textContent).toBe('a(1) | b(1)'));
           });
         }));

      fixmeIvy('FW-718: upgraded service not being initialized correctly on the injector')
          .it('should support using an upgraded service', async(() => {
                class Ng2Service {
                  constructor(@Inject('ng1Value') private ng1Value: string) {}
                  getValue = () => `${this.ng1Value}-bar`;
                }

                @Component({selector: 'ng2', template: '{{ value }}'})
                class Ng2Component {
                  value: string;
                  constructor(ng2Service: Ng2Service) { this.value = ng2Service.getValue(); }
                }

                @NgModule({
                  declarations: [Ng2Component],
                  entryComponents: [Ng2Component],
                  imports: [BrowserModule],
                  providers: [
                    Ng2Service,
                    {
                      provide: 'ng1Value',
                      useFactory: (i: angular.IInjectorService) => i.get('ng1Value'),
                      deps: ['$injector'],
                    },
                  ],
                })
                class Ng2Module {
                  ngDoBootstrap() {}
                }

                const bootstrapFn = (extraProviders: StaticProvider[]) =>
                    platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
                const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
                const ng1Module =
                    angular.module('ng1', [lazyModuleName])
                        .directive(
                            'ng2', downgradeComponent({component: Ng2Component, propagateDigest}))
                        .value('ng1Value', 'foo');

                const element = html('<div><ng2 ng-if="loadNg2"></ng2></div>');
                const $injector = angular.bootstrap(element, [ng1Module.name]);
                const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

                expect(element.textContent).toBe('');
                expect(() => $injector.get(INJECTOR_KEY)).toThrowError();

                $rootScope.$apply('loadNg2 = true');
                expect(element.textContent).toBe('');
                expect(() => $injector.get(INJECTOR_KEY)).toThrowError();

                // Wait for the module to be bootstrapped.
                setTimeout(() => {
                  expect(() => $injector.get(INJECTOR_KEY)).not.toThrow();

                  // Wait for `$evalAsync()` to propagate inputs.
                  setTimeout(() => expect(element.textContent).toBe('foo-bar'));
                });
              }));

      it('should create components inside the Angular zone', async(() => {
           @Component({selector: 'ng2', template: 'In the zone: {{ inTheZone }}'})
           class Ng2Component {
             private inTheZone = false;
             constructor() { this.inTheZone = NgZone.isInAngularZone(); }
           }

           @NgModule({
             declarations: [Ng2Component],
             entryComponents: [Ng2Component],
             imports: [BrowserModule],
           })
           class Ng2Module {
             ngDoBootstrap() {}
           }

           const bootstrapFn = (extraProviders: StaticProvider[]) =>
               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
           const ng1Module =
               angular.module('ng1', [lazyModuleName])
                   .directive(
                       'ng2', downgradeComponent({component: Ng2Component, propagateDigest}));

           const element = html('<ng2></ng2>');
           angular.bootstrap(element, [ng1Module.name]);

           // Wait for the module to be bootstrapped.
           setTimeout(() => {
             // Wait for `$evalAsync()` to propagate inputs.
             setTimeout(() => expect(element.textContent).toBe('In the zone: true'));
           });
         }));

      it('should destroy components inside the Angular zone', async(() => {
           let destroyedInTheZone = false;

           @Component({selector: 'ng2', template: ''})
           class Ng2Component implements OnDestroy {
             ngOnDestroy() { destroyedInTheZone = NgZone.isInAngularZone(); }
           }

           @NgModule({
             declarations: [Ng2Component],
             entryComponents: [Ng2Component],
             imports: [BrowserModule],
           })
           class Ng2Module {
             ngDoBootstrap() {}
           }

           const bootstrapFn = (extraProviders: StaticProvider[]) =>
               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
           const ng1Module =
               angular.module('ng1', [lazyModuleName])
                   .directive(
                       'ng2', downgradeComponent({component: Ng2Component, propagateDigest}));

           const element = html('<ng2 ng-if="!hideNg2"></ng2>');
           const $injector = angular.bootstrap(element, [ng1Module.name]);
           const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

           // Wait for the module to be bootstrapped.
           setTimeout(() => {
             $rootScope.$apply('hideNg2 = true');
             expect(destroyedInTheZone).toBe(true);
           });
         }));

      it('should propagate input changes inside the Angular zone', async(() => {
           let ng2Component: Ng2Component;

           @Component({selector: 'ng2', template: ''})
           class Ng2Component implements OnChanges {
             @Input() attrInput = 'foo';
             @Input() propInput = 'foo';

             constructor() { ng2Component = this; }
             ngOnChanges() {}
           }

           @NgModule({
             declarations: [Ng2Component],
             entryComponents: [Ng2Component],
             imports: [BrowserModule],
           })
           class Ng2Module {
             ngDoBootstrap() {}
           }

           const bootstrapFn = (extraProviders: StaticProvider[]) =>
               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
           const ng1Module =
               angular.module('ng1', [lazyModuleName])
                   .directive('ng2', downgradeComponent({component: Ng2Component, propagateDigest}))
                   .run(($rootScope: angular.IRootScopeService) => {
                     $rootScope.attrVal = 'bar';
                     $rootScope.propVal = 'bar';
                   });

           const element = html('<ng2 attr-input="{{ attrVal }}" [prop-input]="propVal"></ng2>');
           const $injector = angular.bootstrap(element, [ng1Module.name]);
           const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

           setTimeout(() => {    // Wait for the module to be bootstrapped.
             setTimeout(() => {  // Wait for `$evalAsync()` to propagate inputs.
               const expectToBeInNgZone = () => expect(NgZone.isInAngularZone()).toBe(true);
               const changesSpy =
                   spyOn(ng2Component, 'ngOnChanges').and.callFake(expectToBeInNgZone);

               expect(ng2Component.attrInput).toBe('bar');
               expect(ng2Component.propInput).toBe('bar');

               $rootScope.$apply('attrVal = "baz"');
               expect(ng2Component.attrInput).toBe('baz');
               expect(ng2Component.propInput).toBe('bar');
               expect(changesSpy).toHaveBeenCalledTimes(1);

               $rootScope.$apply('propVal = "qux"');
               expect(ng2Component.attrInput).toBe('baz');
               expect(ng2Component.propInput).toBe('qux');
               expect(changesSpy).toHaveBeenCalledTimes(2);
             });
           });
         }));

      it('should create and destroy nested, asynchronously instantiated components inside the Angular zone',
         async(() => {
           let createdInTheZone = false;
           let destroyedInTheZone = false;

           @Component({
             selector: 'test',
             template: '',
           })
           class TestComponent implements OnDestroy {
             constructor() { createdInTheZone = NgZone.isInAngularZone(); }
             ngOnDestroy() { destroyedInTheZone = NgZone.isInAngularZone(); }
           }

           @Component({
             selector: 'wrapper',
             template: '<ng-content></ng-content>',
           })
           class WrapperComponent {
           }

           @NgModule({
             declarations: [TestComponent, WrapperComponent],
             entryComponents: [TestComponent, WrapperComponent],
             imports: [BrowserModule],
           })
           class Ng2Module {
             ngDoBootstrap() {}
           }

           const bootstrapFn = (extraProviders: StaticProvider[]) =>
               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
           const ng1Module =
               angular.module('ng1', [lazyModuleName])
                   .directive(
                       'test', downgradeComponent({component: TestComponent, propagateDigest}))
                   .directive(
                       'wrapper',
                       downgradeComponent({component: WrapperComponent, propagateDigest}));

           // Important: `ng-if` makes `<test>` render asynchronously.
           const element = html('<wrapper><test ng-if="showNg2"></test></wrapper>');
           const $injector = angular.bootstrap(element, [ng1Module.name]);
           const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

           // Wait for the module to be bootstrapped.
           setTimeout(() => {
             // Create nested component asynchronously.
             expect(createdInTheZone).toBe(false);

             $rootScope.$apply('showNg2 = true');
             expect(createdInTheZone).toBe(true);

             // Destroy nested component asynchronously.
             expect(destroyedInTheZone).toBe(false);

             $rootScope.$apply('showNg2 = false');
             expect(destroyedInTheZone).toBe(true);
           });
         }));

      it('should wire up the component for change detection', async(() => {
           @Component(
               {selector: 'ng2', template: '{{ count }}<button (click)="increment()"></button>'})
           class Ng2Component {
             private count = 0;
             increment() { ++this.count; }
           }

           @NgModule({
             declarations: [Ng2Component],
             entryComponents: [Ng2Component],
             imports: [BrowserModule],
           })
           class Ng2Module {
             ngDoBootstrap() {}
           }

           const bootstrapFn = (extraProviders: StaticProvider[]) =>
               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
           const ng1Module =
               angular.module('ng1', [lazyModuleName])
                   .directive(
                       'ng2', downgradeComponent({component: Ng2Component, propagateDigest}));

           const element = html('<ng2></ng2>');
           angular.bootstrap(element, [ng1Module.name]);

           setTimeout(() => {    // Wait for the module to be bootstrapped.
             setTimeout(() => {  // Wait for `$evalAsync()` to propagate inputs.
               const button = element.querySelector('button') !;
               expect(element.textContent).toBe('0');

               button.click();
               expect(element.textContent).toBe('1');

               button.click();
               expect(element.textContent).toBe('2');
             });
           });
         }));

      it('should wire up nested, asynchronously instantiated components for change detection',
         async(() => {
           @Component(
               {selector: 'test', template: '{{ count }}<button (click)="increment()"></button>'})
           class TestComponent {
             count = 0;
             increment() { ++this.count; }
           }

           @Component({
             selector: 'wrapper',
             template: '<ng-content></ng-content>',
           })
           class WrapperComponent {
           }

           @NgModule({
             declarations: [TestComponent, WrapperComponent],
             entryComponents: [TestComponent, WrapperComponent],
             imports: [BrowserModule],
           })
           class Ng2Module {
             ngDoBootstrap() {}
           }

           const bootstrapFn = (extraProviders: StaticProvider[]) =>
               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
           const ng1Module =
               angular.module('ng1', [lazyModuleName])
                   .directive(
                       'test', downgradeComponent({component: TestComponent, propagateDigest}))
                   .directive(
                       'wrapper',
                       downgradeComponent({component: WrapperComponent, propagateDigest}));

           // Important: `ng-if` makes `<test>` render asynchronously.
           const element = html('<wrapper><test ng-if="showNg2"></test></wrapper>');
           const $injector = angular.bootstrap(element, [ng1Module.name]);
           const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

           // Wait for the module to be bootstrapped.
           setTimeout(() => {
             // Create nested component asynchronously.
             $rootScope.$apply('showNg2 = true');
             const button = element.querySelector('button') !;

             expect(element.textContent).toBe('0');

             button.click();
             expect(element.textContent).toBe('1');

             button.click();
             expect(element.textContent).toBe('2');
           });
         }));

      it('should run the lifecycle hooks in the correct order', async(() => {
           const logs: string[] = [];
           let rootScope: angular.IRootScopeService;

           @Component({
             selector: 'ng2',
             template: `
               {{ value }}
               <button (click)="value = 'qux'"></button>
               <ng-content></ng-content>
             `
           })
           class Ng2Component implements AfterContentChecked,
               AfterContentInit, AfterViewChecked, AfterViewInit, DoCheck, OnChanges, OnDestroy,
               OnInit {
             @Input() value = 'foo';

             ngAfterContentChecked() { this.log('AfterContentChecked'); }
             ngAfterContentInit() { this.log('AfterContentInit'); }
             ngAfterViewChecked() { this.log('AfterViewChecked'); }
             ngAfterViewInit() { this.log('AfterViewInit'); }
             ngDoCheck() { this.log('DoCheck'); }
             ngOnChanges() { this.log('OnChanges'); }
             ngOnDestroy() { this.log('OnDestroy'); }
             ngOnInit() { this.log('OnInit'); }

             private log(hook: string) { logs.push(`${hook}(${this.value})`); }
           }

           @NgModule({
             declarations: [Ng2Component],
             entryComponents: [Ng2Component],
             imports: [BrowserModule],
           })
           class Ng2Module {
             ngDoBootstrap() {}
           }

           const bootstrapFn = (extraProviders: StaticProvider[]) =>
               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
           const ng1Module =
               angular.module('ng1', [lazyModuleName])
                   .directive('ng2', downgradeComponent({component: Ng2Component, propagateDigest}))
                   .run(($rootScope: angular.IRootScopeService) => {
                     rootScope = $rootScope;
                     rootScope.value = 'bar';
                   });

           const element =
               html('<div><ng2 value="{{ value }}" ng-if="!hideNg2">Content</ng2></div>');
           angular.bootstrap(element, [ng1Module.name]);

           setTimeout(() => {    // Wait for the module to be bootstrapped.
             setTimeout(() => {  // Wait for `$evalAsync()` to propagate inputs.
               const button = element.querySelector('button') !;

               // Once initialized.
               expect(multiTrim(element.textContent)).toBe('bar Content');
               expect(logs).toEqual([
                 // `ngOnChanges()` call triggered directly through the `inputChanges`
                 // $watcher.
                 'OnChanges(bar)',
                 // Initial CD triggered directly through the `detectChanges()` or
                 // `inputChanges`
                 // $watcher (for `propagateDigest` true/false respectively).
                 'OnInit(bar)',
                 'DoCheck(bar)',
                 'AfterContentInit(bar)',
                 'AfterContentChecked(bar)',
                 'AfterViewInit(bar)',
                 'AfterViewChecked(bar)',
                 ...(propagateDigest ?
                         [
                           // CD triggered directly through the `detectChanges()` $watcher (2nd
                           // $digest).
                           'DoCheck(bar)',
                           'AfterContentChecked(bar)',
                           'AfterViewChecked(bar)',
                         ] :
                         []),
                 // CD triggered due to entering/leaving the NgZone (in `downgradeFn()`).
                 'DoCheck(bar)',
                 'AfterContentChecked(bar)',
                 'AfterViewChecked(bar)',
               ]);
               logs.length = 0;

               // Change inputs and run `$digest`.
               rootScope.$apply('value = "baz"');
               expect(multiTrim(element.textContent)).toBe('baz Content');
               expect(logs).toEqual([
                 // `ngOnChanges()` call triggered directly through the `inputChanges`
                 // $watcher.
                 'OnChanges(baz)',
                 // `propagateDigest: true` (3 CD runs):
                 //   - CD triggered due to entering/leaving the NgZone (in `inputChanges`
                 //   $watcher).
                 //   - CD triggered directly through the `detectChanges()` $watcher.
                 //   - CD triggered due to entering/leaving the NgZone (in `detectChanges`
                 //   $watcher).
                 // `propagateDigest: false` (2 CD runs):
                 //   - CD triggered directly through the `inputChanges` $watcher.
                 //   - CD triggered due to entering/leaving the NgZone (in `inputChanges`
                 //   $watcher).
                 'DoCheck(baz)',
                 'AfterContentChecked(baz)',
                 'AfterViewChecked(baz)',
                 'DoCheck(baz)',
                 'AfterContentChecked(baz)',
                 'AfterViewChecked(baz)',
                 ...(propagateDigest ?
                         [
                           'DoCheck(baz)',
                           'AfterContentChecked(baz)',
                           'AfterViewChecked(baz)',
                         ] :
                         []),
               ]);
               logs.length = 0;

               // Run `$digest` (without changing inputs).
               rootScope.$digest();
               expect(multiTrim(element.textContent)).toBe('baz Content');
               expect(logs).toEqual(
                   propagateDigest ?
                       [
                         // CD triggered directly through the `detectChanges()` $watcher.
                         'DoCheck(baz)',
                         'AfterContentChecked(baz)',
                         'AfterViewChecked(baz)',
                         // CD triggered due to entering/leaving the NgZone (in the above
                         // $watcher).
                         'DoCheck(baz)',
                         'AfterContentChecked(baz)',
                         'AfterViewChecked(baz)',
                       ] :
                       []);
               logs.length = 0;

               // Trigger change detection (without changing inputs).
               button.click();
               expect(multiTrim(element.textContent)).toBe('qux Content');
               expect(logs).toEqual([
                 'DoCheck(qux)',
                 'AfterContentChecked(qux)',
                 'AfterViewChecked(qux)',
               ]);
               logs.length = 0;

               // Destroy the component.
               rootScope.$apply('hideNg2 = true');
               expect(logs).toEqual([
                 'OnDestroy(qux)',
               ]);
               logs.length = 0;
             });
           });
         }));

      it('should detach hostViews from the ApplicationRef once destroyed', async(() => {
           let ng2Component: Ng2Component;

           @Component({selector: 'ng2', template: ''})
           class Ng2Component {
             constructor(public appRef: ApplicationRef) {
               ng2Component = this;
               spyOn(appRef, 'attachView').and.callThrough();
               spyOn(appRef, 'detachView').and.callThrough();
             }
           }

           @NgModule({
             declarations: [Ng2Component],
             entryComponents: [Ng2Component],
             imports: [BrowserModule],
           })
           class Ng2Module {
             ngDoBootstrap() {}
           }

           const bootstrapFn = (extraProviders: StaticProvider[]) =>
               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
           const ng1Module =
               angular.module('ng1', [lazyModuleName])
                   .directive(
                       'ng2', downgradeComponent({component: Ng2Component, propagateDigest}));

           const element = html('<ng2 ng-if="!hideNg2"></ng2>');
           const $injector = angular.bootstrap(element, [ng1Module.name]);
           const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

           setTimeout(() => {    // Wait for the module to be bootstrapped.
             setTimeout(() => {  // Wait for the hostView to be attached (during the `$digest`).
               const hostView: ViewRef =
                   (ng2Component.appRef.attachView as jasmine.Spy).calls.mostRecent().args[0];

               expect(hostView.destroyed).toBe(false);

               $rootScope.$apply('hideNg2 = true');

               expect(hostView.destroyed).toBe(true);
               expect(ng2Component.appRef.detachView).toHaveBeenCalledWith(hostView);
             });
           });
         }));

      it('should only retrieve the Angular zone once (and cache it for later use)',
         fakeAsync(() => {
           let count = 0;
           let getNgZoneCount = 0;

           @Component(
               {selector: 'ng2', template: 'Count: {{ count }} | In the zone: {{ inTheZone }}'})
           class Ng2Component {
             private count = ++count;
             private inTheZone = false;
             constructor() { this.inTheZone = NgZone.isInAngularZone(); }
           }

           @NgModule({
             declarations: [Ng2Component],
             entryComponents: [Ng2Component],
             imports: [BrowserModule],
           })
           class Ng2Module {
             constructor(injector: Injector) {
               const originalGet = injector.get;
               injector.get = function(token: any) {
                 if (token === NgZone) ++getNgZoneCount;
                 return originalGet.apply(injector, arguments);
               };
             }
             ngDoBootstrap() {}
           }

           const tickDelay = browserDetection.isIE ? 100 : 0;
           const bootstrapFn = (extraProviders: StaticProvider[]) =>
               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
           const ng1Module =
               angular.module('ng1', [lazyModuleName])
                   .directive(
                       'ng2', downgradeComponent({component: Ng2Component, propagateDigest}));

           const element = html('<div><ng2 ng-if="showNg2"></ng2></div>');
           const $injector = angular.bootstrap(element, [ng1Module.name]);
           const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;

           $rootScope.$apply('showNg2 = true');
           tick(tickDelay);  // Wait for the module to be bootstrapped and `$evalAsync()` to
                             // propagate inputs.

           const injector = ($injector.get(LAZY_MODULE_REF) as LazyModuleRef).injector !;
           const injectorGet = injector.get;
           spyOn(injector, 'get').and.callFake((...args: any[]) => {
             expect(args[0]).not.toBe(NgZone);
             return injectorGet.apply(injector, args);
           });

           expect(element.textContent).toBe('Count: 1 | In the zone: true');

           $rootScope.$apply('showNg2 = false');
           expect(element.textContent).toBe('');

           $rootScope.$apply('showNg2 = true');
           tick(tickDelay);  // Wait for `$evalAsync()` to propagate inputs.
           expect(element.textContent).toBe('Count: 2 | In the zone: true');

           $rootScope.$destroy();
         }));

      it('should give access to both injectors in the Angular module\'s constructor', async(() => {
           let $injectorFromNg2: angular.IInjectorService|null = null;

           @Component({selector: 'ng2', template: ''})
           class Ng2Component {
           }

           @NgModule({
             declarations: [Ng2Component],
             entryComponents: [Ng2Component],
             imports: [BrowserModule],
           })
           class Ng2Module {
             constructor(injector: Injector) {
               $injectorFromNg2 = injector.get<angular.IInjectorService>('$injector' as any);
             }

             ngDoBootstrap() {}
           }

           const bootstrapFn = (extraProviders: StaticProvider[]) =>
               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
           const ng1Module =
               angular.module('ng1', [lazyModuleName])
                   .directive(
                       'ng2', downgradeComponent({component: Ng2Component, propagateDigest}));

           const element = html('<ng2></ng2>');
           const $injectorFromNg1 = angular.bootstrap(element, [ng1Module.name]);

           // Wait for the module to be bootstrapped.
           setTimeout(() => expect($injectorFromNg2).toBe($injectorFromNg1));
         }));

      describe('(common error)', () => {
        let Ng2CompA: Type<any>;
        let Ng2CompB: Type<any>;
        let downModA: string;
        let downModB: string;
        let errorSpy: jasmine.Spy;

        const doDowngradeModule = (module: Type<any>) => {
          const bootstrapFn = (extraProviders: StaticProvider[]) =>
              (getPlatform() || platformBrowserDynamic(extraProviders)).bootstrapModule(module);
          return downgradeModule(bootstrapFn);
        };

        beforeEach(() => {
          @Component({selector: 'ng2A', template: 'a'})
          class Ng2ComponentA {
          }

          @Component({selector: 'ng2B', template: 'b'})
          class Ng2ComponentB {
          }

          @NgModule({
            declarations: [Ng2ComponentA],
            entryComponents: [Ng2ComponentA],
            imports: [BrowserModule],
          })
          class Ng2ModuleA {
            ngDoBootstrap() {}
          }

          @NgModule({
            declarations: [Ng2ComponentB],
            entryComponents: [Ng2ComponentB],
            imports: [BrowserModule],
          })
          class Ng2ModuleB {
            ngDoBootstrap() {}
          }

          Ng2CompA = Ng2ComponentA;
          Ng2CompB = Ng2ComponentB;
          downModA = doDowngradeModule(Ng2ModuleA);
          downModB = doDowngradeModule(Ng2ModuleB);
          errorSpy = jasmine.createSpy($EXCEPTION_HANDLER);
        });

        // In the tests below, some of the components' bootstrap process is interrupted by an error.
        // If the bootstrap process for other components/modules is not completed in time, there is
        // a chance that some global state is retained, possibly messing subsequent tests.
        // Explicitly clean up after each test to prevent that.
        afterEach(() => setTempInjectorRef(null !));

        it('should throw if no downgraded module is included', async(() => {
             const ng1Module = angular.module('ng1', [])
                                   .value($EXCEPTION_HANDLER, errorSpy)
                                   .directive('ng2A', downgradeComponent({
                                                component: Ng2CompA,
                                                downgradedModule: downModA, propagateDigest,
                                              }))
                                   .directive('ng2B', downgradeComponent({
                                                component: Ng2CompB,
                                                propagateDigest,
                                              }));

             const element = html('<ng2-a></ng2-a> | <ng2-b></ng2-b>');
             angular.bootstrap(element, [ng1Module.name]);

             expect(errorSpy).toHaveBeenCalledTimes(2);
             expect(errorSpy).toHaveBeenCalledWith(
                 new Error(
                     'Error while instantiating component \'Ng2ComponentA\': Not a valid ' +
                     '\'@angular/upgrade\' application.\n' +
                     'Did you forget to downgrade an Angular module or include it in the AngularJS ' +
                     'application?'),
                 '<ng2-a>');
             expect(errorSpy).toHaveBeenCalledWith(
                 new Error(
                     'Error while instantiating component \'Ng2ComponentB\': Not a valid ' +
                     '\'@angular/upgrade\' application.\n' +
                     'Did you forget to downgrade an Angular module or include it in the AngularJS ' +
                     'application?'),
                 '<ng2-b>');
           }));

        it('should throw if the corresponding downgraded module is not included', async(() => {
             const ng1Module = angular.module('ng1', [downModA])
                                   .value($EXCEPTION_HANDLER, errorSpy)
                                   .directive('ng2A', downgradeComponent({
                                                component: Ng2CompA,
                                                downgradedModule: downModA, propagateDigest,
                                              }))
                                   .directive('ng2B', downgradeComponent({
                                                component: Ng2CompB,
                                                downgradedModule: downModB, propagateDigest,
                                              }));

             const element = html('<ng2-a></ng2-a> | <ng2-b></ng2-b>');
             angular.bootstrap(element, [ng1Module.name]);

             expect(errorSpy).toHaveBeenCalledTimes(1);
             expect(errorSpy).toHaveBeenCalledWith(
                 new Error(
                     'Error while instantiating component \'Ng2ComponentB\': Unable to find the ' +
                     'specified downgraded module.\n' +
                     'Did you forget to downgrade an Angular module or include it in the AngularJS ' +
                     'application?'),
                 '<ng2-b>');
           }));

        it('should throw if `downgradedModule` is not specified and there are multiple downgraded modules',
           async(() => {
             const ng1Module = angular.module('ng1', [downModA, downModB])
                                   .value($EXCEPTION_HANDLER, errorSpy)
                                   .directive('ng2A', downgradeComponent({
                                                component: Ng2CompA,
                                                downgradedModule: downModA, propagateDigest,
                                              }))
                                   .directive('ng2B', downgradeComponent({
                                                component: Ng2CompB,
                                                propagateDigest,
                                              }));

             const element = html('<ng2-a></ng2-a> | <ng2-b></ng2-b>');
             angular.bootstrap(element, [ng1Module.name]);

             expect(errorSpy).toHaveBeenCalledTimes(1);
             expect(errorSpy).toHaveBeenCalledWith(
                 new Error(
                     'Error while instantiating component \'Ng2ComponentB\': \'downgradedModule\' not ' +
                     'specified.\n' +
                     'This application contains more than one downgraded Angular module, thus you need ' +
                     'to always specify \'downgradedModule\' when downgrading components and ' +
                     'injectables.'),
                 '<ng2-b>');
           }));
      });
    });
  });
});