di_spec.ts

/**
 * @license
 * Copyright Google LLC 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 {CommonModule} from '@angular/common';
import {Attribute, ChangeDetectorRef, Component, ComponentFactoryResolver, ComponentRef, createEnvironmentInjector, Directive, ElementRef, ENVIRONMENT_INITIALIZER, EnvironmentInjector, EventEmitter, forwardRef, Host, HostBinding, ImportedNgModuleProviders, importProvidersFrom, ImportProvidersSource, inject, Inject, Injectable, InjectFlags, InjectionToken, INJECTOR, Injector, Input, LOCALE_ID, ModuleWithProviders, NgModule, NgZone, Optional, Output, Pipe, PipeTransform, Provider, Self, SkipSelf, TemplateRef, Type, ViewChild, ViewContainerRef, ViewEncapsulation, ViewRef, ɵcreateInjector as createInjector, ɵDEFAULT_LOCALE_ID as DEFAULT_LOCALE_ID, ɵINJECTOR_SCOPE} from '@angular/core';
import {ViewRef as ViewRefInternal} from '@angular/core/src/render3/view_ref';
import {TestBed} from '@angular/core/testing';
import {By} from '@angular/platform-browser';
import {BehaviorSubject} from 'rxjs';

const getProvidersByToken =
    (providers: Provider[], token: Type<unknown>|InjectionToken<unknown>): Provider[] =>
        providers.filter(provider => (provider as any).provide === token);

const hasProviderWithToken = (providers: Provider[], token: InjectionToken<unknown>): boolean =>
    getProvidersByToken(providers, token).length > 0;

const collectEnvironmentInitializerProviders = (providers: Provider[]) =>
    getProvidersByToken(providers, ENVIRONMENT_INITIALIZER);

function unwrappedImportProvidersFrom(...sources: ImportProvidersSource[]): Provider[] {
  return importProvidersFrom(...sources).ɵproviders;
}

describe('importProvidersFrom', () => {
  // Set of tokens used in various tests.
  const A = new InjectionToken('A');
  const B = new InjectionToken('B');
  const C = new InjectionToken('C');
  const D = new InjectionToken('D');

  it('should collect providers from NgModules', () => {
    @NgModule({
      providers: [
        {provide: C, useValue: 'C'},
        {provide: D, useValue: 'D'},
      ],
    })
    class MyModule2 {
    }
    @NgModule({
      imports: [MyModule2],
      providers: [
        {provide: A, useValue: 'A'},
        {provide: B, useValue: 'B'},
      ],
    })
    class MyModule {
    }
    const providers = unwrappedImportProvidersFrom(MyModule);

    // 4 tokens (A, B, C, D) + 2 providers for each NgModule:
    // - the definition type itself
    // - `INJECTOR_DEF_TYPES`
    // - `ENVIRONMENT_INITIALIZER`
    expect(providers.length).toBe(10);

    expect(hasProviderWithToken(providers, A)).toBe(true);
    expect(hasProviderWithToken(providers, B)).toBe(true);
    expect(hasProviderWithToken(providers, C)).toBe(true);
    expect(hasProviderWithToken(providers, D)).toBe(true);

    // Expect 2 `ENVIRONMENT_INITIALIZER` providers: one for `MyModule`, another was `MyModule2`
    expect(collectEnvironmentInitializerProviders(providers).length).toBe(2);
  });

  it('should collect providers from directly imported ModuleWithProviders', () => {
    @NgModule({})
    class Module {
    }

    const providers = unwrappedImportProvidersFrom({
      ngModule: Module,
      providers: [{provide: A, useValue: 'A'}],
    });
    expect(hasProviderWithToken(providers, A)).toBe(true);
  });

  it('should collect all providers when a module is used twice with different providers (via ModuleWithProviders)',
     () => {
       @NgModule({
         providers: [
           {provide: A, useValue: 'A'}  //
         ]
       })
       class ModuleA {
       }

       @NgModule({imports: [ModuleA]})
       class ModuleB {
         static forRoot(): ModuleWithProviders<ModuleB> {
           return {ngModule: ModuleB, providers: [{provide: B, useValue: 'B'}]};
         }
         static forChild(): ModuleWithProviders<ModuleB> {
           return {ngModule: ModuleB, providers: [{provide: C, useValue: 'C'}]};
         }
       }

       const providers = unwrappedImportProvidersFrom(ModuleB.forRoot(), ModuleB.forChild());

       // Expect 2 `ENVIRONMENT_INITIALIZER` providers: one for `ModuleA`, another one for `ModuleB`
       expect(collectEnvironmentInitializerProviders(providers).length).toBe(2);

       // Expect exactly 1 provider for each module: `ModuleA` and `ModuleB`
       expect(getProvidersByToken(providers, ModuleA).length).toBe(1);
       expect(getProvidersByToken(providers, ModuleB).length).toBe(1);

       // Expect all tokens to be collected.
       expect(hasProviderWithToken(providers, A)).toBe(true);
       expect(hasProviderWithToken(providers, B)).toBe(true);
       expect(hasProviderWithToken(providers, C)).toBe(true);
     });

  it('should process nested arrays within a provider set of ModuleWithProviders type', () => {
    @NgModule()
    class ModuleA {
      static forRoot(): ModuleWithProviders<ModuleA> {
        return {
          ngModule: ModuleA,
          providers: [
            {provide: A, useValue: 'A'},
            // Nested arrays inside the list of providers:
            [{provide: B, useValue: 'B'}, [{provide: C, useValue: 'C'}]]
          ]
        };
      }
    }

    const providers = unwrappedImportProvidersFrom(ModuleA.forRoot());

    // Expect 1 `ENVIRONMENT_INITIALIZER` provider (for `ModuleA`)
    expect(collectEnvironmentInitializerProviders(providers).length).toBe(1);

    // Expect exactly 1 provider for `ModuleA`
    expect(getProvidersByToken(providers, ModuleA).length).toBe(1);

    // Expect all tokens to be collected.
    expect(hasProviderWithToken(providers, A)).toBe(true);
    expect(hasProviderWithToken(providers, B)).toBe(true);
    expect(hasProviderWithToken(providers, C)).toBe(true);
  });

  it('should process nested arrays within provider set of an imported ModuleWithProviders type',
     () => {
       @NgModule()
       class ModuleA {
         static forRoot(): ModuleWithProviders<ModuleA> {
           return {
             ngModule: ModuleA,
             providers: [
               {provide: A, useValue: 'A'},
               // Nested arrays inside the list of providers:
               [{provide: B, useValue: 'B'}, [{provide: C, useValue: 'C'}]]
             ]
           };
         }
       }

       @NgModule({imports: [ModuleA.forRoot()]})
       class ModuleB {
       }

       const providers = unwrappedImportProvidersFrom(ModuleB);

       // Expect 2 `ENVIRONMENT_INITIALIZER` providers: one for `ModuleA`, another one for `ModuleB`
       expect(collectEnvironmentInitializerProviders(providers).length).toBe(2);

       // Expect exactly 1 provider for each module: `ModuleA` and `ModuleB`
       expect(getProvidersByToken(providers, ModuleA).length).toBe(1);
       expect(getProvidersByToken(providers, ModuleB).length).toBe(1);

       // Expect all tokens to be collected.
       expect(hasProviderWithToken(providers, A)).toBe(true);
       expect(hasProviderWithToken(providers, B)).toBe(true);
       expect(hasProviderWithToken(providers, C)).toBe(true);
     });

  it('should collect providers defined via `@NgModule.providers` when ModuleWithProviders type is used',
     () => {
       @NgModule({
         providers: [
           {provide: A, useValue: 'Original A'},  //
           {provide: B, useValue: 'B'},           //
           {provide: D, useValue: 'Original D', multi: true}
         ]
       })
       class ModuleA {
         static forRoot(): ModuleWithProviders<ModuleA> {
           return {
             ngModule: ModuleA,
             providers: [
               {provide: A, useValue: 'Overridden A'},  //
               {provide: C, useValue: 'C'},             //
               {provide: D, useValue: 'Extra D', multi: true}
             ]
           };
         }
       }

       const providers = unwrappedImportProvidersFrom(ModuleA.forRoot());

       // Expect all tokens to be collected.
       expect(hasProviderWithToken(providers, A)).toBe(true);
       expect(hasProviderWithToken(providers, B)).toBe(true);
       expect(hasProviderWithToken(providers, C)).toBe(true);
       expect(hasProviderWithToken(providers, D)).toBe(true);

       const parentEnvInjector = TestBed.inject(EnvironmentInjector);
       const injector = createEnvironmentInjector(providers, parentEnvInjector);

       // Verify that overridden token A has the right value.
       expect(injector.get(A)).toBe('Overridden A');

       // Verify that a multi-provider has both values.
       expect(injector.get(D)).toEqual(['Original D', 'Extra D']);
     });

  it('should not be allowed in component providers', () => {
    @NgModule({})
    class Module {
    }

    expect(() => {
      @Component({
        selector: 'test-cmp',
        template: '',
        // The double array here is necessary to escape the compile-time error, via Provider's
        // `any[]` option.
        providers: [[importProvidersFrom(Module)]],
      })
      class Cmp {
      }

      TestBed.createComponent(Cmp);
    }).toThrowError(/NG0207/);
  });

  it('should import providers from an array of NgModules (may be nested)', () => {
    @NgModule({providers: [{provide: A, useValue: 'A'}]})
    class ModuleA {
    }

    @NgModule({providers: [{provide: B, useValue: 'B'}]})
    class ModuleB {
    }

    const providers = unwrappedImportProvidersFrom([ModuleA, [ModuleB]]);

    expect(hasProviderWithToken(providers, A)).toBeTrue();
    expect(hasProviderWithToken(providers, B)).toBeTrue();
  });

  it('should throw when trying to import providers from standalone components', () => {
    @NgModule({providers: [{provide: A, useValue: 'A'}]})
    class ModuleA {
    }

    @Component({
      standalone: true,
      template: '',
      imports: [ModuleA],
    })
    class StandaloneCmp {
    }

    expect(() => {
      importProvidersFrom(StandaloneCmp);
    })
        .toThrowError(
            'NG0800: Importing providers supports NgModule or ModuleWithProviders but got a standalone component "StandaloneCmp"');
  });
});

describe('di', () => {
  describe('no dependencies', () => {
    it('should create directive with no deps', () => {
      @Directive({selector: '[dir]', exportAs: 'dir'})
      class MyDirective {
        value = 'Created';
      }
      @Component({template: '<div dir #dir="dir">{{ dir.value }}</div>'})
      class MyComp {
      }
      TestBed.configureTestingModule({declarations: [MyDirective, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      const divElement = fixture.nativeElement.querySelector('div');
      expect(divElement.textContent).toContain('Created');
    });
  });

  describe('multi providers', () => {
    it('should process ModuleWithProvider providers after module imports', () => {
      const testToken = new InjectionToken<string[]>('test-multi');

      @NgModule({providers: [{provide: testToken, useValue: 'A', multi: true}]})
      class TestModuleA {
      }

      @NgModule({providers: [{provide: testToken, useValue: 'B', multi: true}]})
      class TestModuleB {
      }

      TestBed.configureTestingModule({
        imports: [
          {
            ngModule: TestModuleA,
            providers: [{provide: testToken, useValue: 'C', multi: true}],
          },
          TestModuleB,
        ]
      });

      expect(TestBed.inject(testToken)).toEqual(['A', 'B', 'C']);
    });
  });

  describe('directive injection', () => {
    let log: string[] = [];

    @Directive({selector: '[dirB]', exportAs: 'dirB'})
    class DirectiveB {
      @Input() value = 'DirB';

      constructor() {
        log.push(this.value);
      }
    }

    beforeEach(() => log = []);

    it('should create directive with intra view dependencies', () => {
      @Directive({selector: '[dirA]', exportAs: 'dirA'})
      class DirectiveA {
        value = 'DirA';
      }

      @Directive({selector: '[dirC]', exportAs: 'dirC'})
      class DirectiveC {
        value: string;

        constructor(dirA: DirectiveA, dirB: DirectiveB) {
          this.value = dirA.value + dirB.value;
        }
      }

      @Component({
        template: `
        <div dirA>
          <span dirB dirC #dir="dirC">{{ dir.value }}</span>
        </div>
      `
      })
      class MyComp {
      }

      TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, DirectiveC, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      const divElement = fixture.nativeElement.querySelector('span');
      expect(divElement.textContent).toContain('DirADirB');
    });

    it('should instantiate injected directives in dependency order', () => {
      @Directive({selector: '[dirA]'})
      class DirectiveA {
        value = 'dirA';

        constructor(dirB: DirectiveB) {
          log.push(`DirA (dep: ${dirB.value})`);
        }
      }

      @Component({template: '<div dirA dirB></div>'})
      class MyComp {
      }

      TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      expect(log).toEqual(['DirB', 'DirA (dep: DirB)']);
    });

    it('should fallback to the module injector', () => {
      @Directive({selector: '[dirA]'})
      class DirectiveA {
        value = 'dirA';

        constructor(dirB: DirectiveB) {
          log.push(`DirA (dep: ${dirB.value})`);
        }
      }

      // - dirB is know to the node injectors
      // - then when dirA tries to inject dirB, it will check the node injector first tree
      // - if not found, it will check the module injector tree
      @Component({template: '<div dirB></div><div dirA></div>'})
      class MyComp {
      }

      TestBed.configureTestingModule({
        declarations: [DirectiveA, DirectiveB, MyComp],
        providers: [{provide: DirectiveB, useValue: {value: 'module'}}]
      });
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      expect(log).toEqual(['DirB', 'DirA (dep: module)']);
    });

    it('should instantiate injected directives before components', () => {
      @Component({selector: 'my-comp', template: ''})
      class MyComp {
        constructor(dirB: DirectiveB) {
          log.push(`Comp (dep: ${dirB.value})`);
        }
      }

      @Component({template: '<my-comp dirB></my-comp>'})
      class MyApp {
      }

      TestBed.configureTestingModule({declarations: [DirectiveB, MyComp, MyApp]});
      const fixture = TestBed.createComponent(MyApp);
      fixture.detectChanges();

      expect(log).toEqual(['DirB', 'Comp (dep: DirB)']);
    });

    it('should inject directives in the correct order in a for loop', () => {
      @Directive({selector: '[dirA]'})
      class DirectiveA {
        constructor(dir: DirectiveB) {
          log.push(`DirA (dep: ${dir.value})`);
        }
      }

      @Component({template: '<div dirA dirB *ngFor="let i of array"></div>'})
      class MyComp {
        array = [1, 2, 3];
      }

      TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      expect(log).toEqual(
          ['DirB', 'DirA (dep: DirB)', 'DirB', 'DirA (dep: DirB)', 'DirB', 'DirA (dep: DirB)']);
    });

    it('should instantiate directives with multiple out-of-order dependencies', () => {
      @Directive({selector: '[dirA]'})
      class DirectiveA {
        value = 'DirA';

        constructor() {
          log.push(this.value);
        }
      }

      @Directive({selector: '[dirC]'})
      class DirectiveC {
        value = 'DirC';

        constructor() {
          log.push(this.value);
        }
      }

      @Directive({selector: '[dirB]'})
      class DirectiveB {
        constructor(dirA: DirectiveA, dirC: DirectiveC) {
          log.push(`DirB (deps: ${dirA.value} and ${dirC.value})`);
        }
      }

      @Component({template: '<div dirA dirB dirC></div>'})
      class MyComp {
      }

      TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, DirectiveC, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      expect(log).toEqual(['DirA', 'DirC', 'DirB (deps: DirA and DirC)']);
    });

    it('should instantiate in the correct order for complex case', () => {
      @Directive({selector: '[dirC]'})
      class DirectiveC {
        value = 'DirC';

        constructor(dirB: DirectiveB) {
          log.push(`DirC (dep: ${dirB.value})`);
        }
      }

      @Directive({selector: '[dirA]'})
      class DirectiveA {
        value = 'DirA';

        constructor(dirC: DirectiveC) {
          log.push(`DirA (dep: ${dirC.value})`);
        }
      }

      @Directive({selector: '[dirD]'})
      class DirectiveD {
        value = 'DirD';

        constructor(dirA: DirectiveA) {
          log.push(`DirD (dep: ${dirA.value})`);
        }
      }

      @Component({selector: 'my-comp', template: ''})
      class MyComp {
        constructor(dirD: DirectiveD) {
          log.push(`Comp (dep: ${dirD.value})`);
        }
      }

      @Component({template: '<my-comp dirA dirB dirC dirD></my-comp>'})
      class MyApp {
      }

      TestBed.configureTestingModule(
          {declarations: [DirectiveA, DirectiveB, DirectiveC, DirectiveD, MyComp, MyApp]});
      const fixture = TestBed.createComponent(MyApp);
      fixture.detectChanges();

      expect(log).toEqual(
          ['DirB', 'DirC (dep: DirB)', 'DirA (dep: DirC)', 'DirD (dep: DirA)', 'Comp (dep: DirD)']);
    });

    it('should instantiate in correct order with mixed parent and peer dependencies', () => {
      @Component({template: '<div dirA dirB dirC></div>'})
      class MyApp {
        value = 'App';
      }

      @Directive({selector: '[dirA]'})
      class DirectiveA {
        constructor(dirB: DirectiveB, app: MyApp) {
          log.push(`DirA (deps: ${dirB.value} and ${app.value})`);
        }
      }

      TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyApp]});
      const fixture = TestBed.createComponent(MyApp);
      fixture.detectChanges();

      expect(log).toEqual(['DirB', 'DirA (deps: DirB and App)']);
    });

    it('should not use a parent when peer dep is available', () => {
      let count = 1;

      @Directive({selector: '[dirB]'})
      class DirectiveB {
        count: number;

        constructor() {
          log.push(`DirB`);
          this.count = count++;
        }
      }

      @Directive({selector: '[dirA]'})
      class DirectiveA {
        constructor(dirB: DirectiveB) {
          log.push(`DirA (dep: DirB - ${dirB.count})`);
        }
      }

      @Component({selector: 'my-comp', template: '<div dirA dirB></div>'})
      class MyComp {
      }

      @Component({template: '<my-comp dirB></my-comp>'})
      class MyApp {
      }

      TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp, MyApp]});
      const fixture = TestBed.createComponent(MyApp);
      fixture.detectChanges();

      expect(log).toEqual(['DirB', 'DirB', 'DirA (dep: DirB - 2)']);
    });

    describe('dependencies in parent views', () => {
      @Directive({selector: '[dirA]', exportAs: 'dirA'})
      class DirectiveA {
        injector: Injector;

        constructor(public dirB: DirectiveB, public vcr: ViewContainerRef) {
          this.injector = vcr.injector;
        }
      }

      @Component(
          {selector: 'my-comp', template: '<div dirA #dir="dirA">{{ dir.dirB.value }}</div>'})
      class MyComp {
      }

      it('should find dependencies on component hosts', () => {
        @Component({template: '<my-comp dirB></my-comp>'})
        class MyApp {
        }

        TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp, MyApp]});
        const fixture = TestBed.createComponent(MyApp);
        fixture.detectChanges();

        const divElement = fixture.nativeElement.querySelector('div');
        expect(divElement.textContent).toEqual('DirB');
      });

      it('should find dependencies for directives in embedded views', () => {
        @Component({
          template: `<div dirB>
            <div *ngIf="showing">
              <div dirA #dir="dirA">{{ dir.dirB.value }}</div>
            </div>
          </div>`
        })
        class MyApp {
          showing = false;
        }

        TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp, MyApp]});
        const fixture = TestBed.createComponent(MyApp);
        fixture.componentInstance.showing = true;
        fixture.detectChanges();

        const divElement = fixture.nativeElement.querySelector('div');
        expect(divElement.textContent).toEqual('DirB');
      });

      it('should find dependencies of directives nested deeply in inline views', () => {
        @Component({
          template: `<div dirB>
            <ng-container *ngIf="!skipContent">
              <ng-container *ngIf="!skipContent2">
                <div dirA #dir="dirA">{{ dir.dirB.value }}</div>
              </ng-container>
            </ng-container>
          </div>`
        })
        class MyApp {
          skipContent = false;
          skipContent2 = false;
        }

        TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyApp]});
        const fixture = TestBed.createComponent(MyApp);
        fixture.detectChanges();

        const divElement = fixture.nativeElement.querySelector('div');
        expect(divElement.textContent).toEqual('DirB');
      });

      it('should find dependencies in declaration tree of ng-template (not insertion tree)', () => {
        @Directive({selector: '[structuralDir]'})
        class StructuralDirective {
          @Input() tmp!: TemplateRef<any>;

          constructor(public vcr: ViewContainerRef) {}

          create() {
            this.vcr.createEmbeddedView(this.tmp);
          }
        }

        @Component({
          template: `<div dirB value="declaration">
           <ng-template #foo>
               <div dirA #dir="dirA">{{ dir.dirB.value }}</div>
           </ng-template>
         </div>

         <div dirB value="insertion">
           <div structuralDir [tmp]="foo"></div>
           <!-- insertion point -->
         </div>`
        })
        class MyComp {
          @ViewChild(StructuralDirective) structuralDir!: StructuralDirective;
        }

        TestBed.configureTestingModule(
            {declarations: [StructuralDirective, DirectiveA, DirectiveB, MyComp]});
        const fixture = TestBed.createComponent(MyComp);
        fixture.detectChanges();
        fixture.componentInstance.structuralDir.create();
        fixture.detectChanges();

        const divElement = fixture.nativeElement.querySelector('div[value=insertion]');
        expect(divElement.textContent).toEqual('declaration');
      });

      it('should create injectors on second template pass', () => {
        @Component({
          template: `<div>
            <my-comp dirB></my-comp>
            <my-comp dirB></my-comp>
          </div>`
        })
        class MyApp {
        }

        TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp, MyApp]});
        const fixture = TestBed.createComponent(MyApp);
        fixture.detectChanges();

        const divElement = fixture.nativeElement.querySelector('div');
        expect(divElement.textContent).toEqual('DirBDirB');
      });

      it('should create injectors and host bindings in same view', () => {
        @Directive({selector: '[hostBindingDir]'})
        class HostBindingDirective {
          @HostBinding('id') id = 'foo';
        }

        @Component({
          template: `<div dirB hostBindingDir>
            <p dirA #dir="dirA">{{ dir.dirB.value }}</p>
          </div>`
        })
        class MyApp {
          @ViewChild(HostBindingDirective) hostBindingDir!: HostBindingDirective;
          @ViewChild(DirectiveA) dirA!: DirectiveA;
        }

        TestBed.configureTestingModule(
            {declarations: [DirectiveA, DirectiveB, HostBindingDirective, MyApp]});
        const fixture = TestBed.createComponent(MyApp);
        fixture.detectChanges();

        const divElement = fixture.nativeElement.querySelector('div');
        expect(divElement.textContent).toEqual('DirB');
        expect(divElement.id).toEqual('foo');

        const dirA = fixture.componentInstance.dirA;
        expect(dirA.vcr.injector).toEqual(dirA.injector);

        const hostBindingDir = fixture.componentInstance.hostBindingDir;
        hostBindingDir.id = 'bar';
        fixture.detectChanges();
        expect(divElement.id).toBe('bar');
      });

      it('dynamic components should find dependencies when parent is projected', () => {
        @Directive({selector: '[dirA]'})
        class DirA {
        }
        @Directive({selector: '[dirB]'})
        class DirB {
        }
        @Component({selector: 'child', template: ''})
        class Child {
          constructor(@Optional() readonly dirA: DirA, @Optional() readonly dirB: DirB) {}
        }
        @Component({
          selector: 'projector',
          template: '<ng-content></ng-content>',
        })
        class Projector {
        }

        @Component({
          template: `
          <projector>
            <div dirA>
              <ng-container #childOrigin></ng-container>
              <ng-container #childOriginWithDirB dirB></ng-container>
            </div>
          </projector>`
        })
        class MyApp {
          @ViewChild('childOrigin', {read: ViewContainerRef, static: true})
          childOrigin!: ViewContainerRef;
          @ViewChild('childOriginWithDirB', {read: ViewContainerRef, static: true})
          childOriginWithDirB!: ViewContainerRef;
          childFactory = this.resolver.resolveComponentFactory(Child);

          constructor(readonly resolver: ComponentFactoryResolver, readonly injector: Injector) {}

          addChild() {
            return this.childOrigin.createComponent(this.childFactory);
          }
          addChildWithDirB() {
            return this.childOriginWithDirB.createComponent(this.childFactory);
          }
        }

        const fixture =
            TestBed.configureTestingModule({declarations: [Child, DirA, DirB, Projector, MyApp]})
                .createComponent(MyApp);
        const child = fixture.componentInstance.addChild();
        expect(child).toBeDefined();
        expect(child.instance.dirA)
            .not.toBeNull('dirA should be found. It is on the parent of the viewContainerRef.');
        const child2 = fixture.componentInstance.addChildWithDirB();
        expect(child2).toBeDefined();
        expect(child2.instance.dirA)
            .not.toBeNull('dirA should be found. It is on the parent of the viewContainerRef.');
        expect(child2.instance.dirB)
            .toBeNull(
                'dirB appears on the ng-container and should not be found because the ' +
                'viewContainerRef.createComponent node is inserted next to the container.');
      });
    });

    it('should throw if directive is not found anywhere', () => {
      @Directive({selector: '[dirB]'})
      class DirectiveB {
        constructor() {}
      }

      @Directive({selector: '[dirA]'})
      class DirectiveA {
        constructor(siblingDir: DirectiveB) {}
      }

      @Component({template: '<div dirA></div>'})
      class MyComp {
      }

      TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp]});
      expect(() => TestBed.createComponent(MyComp)).toThrowError(/No provider for DirectiveB/);
    });

    it('should throw if directive is not found in ancestor tree', () => {
      @Directive({selector: '[dirB]'})
      class DirectiveB {
        constructor() {}
      }

      @Directive({selector: '[dirA]'})
      class DirectiveA {
        constructor(siblingDir: DirectiveB) {}
      }

      @Component({template: '<div dirA></div><div dirB></div>'})
      class MyComp {
      }

      TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp]});
      expect(() => TestBed.createComponent(MyComp)).toThrowError(/No provider for DirectiveB/);
    });

    it('should not have access to the directive injector in a standalone injector from within a directive-level provider factory',
       () => {
         // https://github.com/angular/angular/issues/42651
         class TestA {
           constructor(public injector: string) {}
         }
         class TestB {
           constructor(public a: TestA) {}
         }

         function createTestB() {
           // Setup a standalone injector that provides `TestA`, which is resolved from a
           // standalone child injector that requests `TestA` as a dependency for `TestB`.
           // Although we're inside a directive factory and therefore have access to the
           // directive-level injector, `TestA` has to be resolved from the standalone injector.
           const parent = Injector.create({
             providers: [{provide: TestA, useFactory: () => new TestA('standalone'), deps: []}],
             name: 'TestA',
           });
           const child = Injector.create({
             providers: [{provide: TestB, useClass: TestB, deps: [TestA]}],
             parent,
             name: 'TestB',
           });
           return child.get(TestB);
         }

         @Component({
           template: '',
           providers: [
             {provide: TestA, useFactory: () => new TestA('component'), deps: []},
             {provide: TestB, useFactory: createTestB},
           ],
         })
         class MyComp {
           constructor(public readonly testB: TestB) {}
         }

         TestBed.configureTestingModule({declarations: [MyComp]});

         const cmp = TestBed.createComponent(MyComp);
         expect(cmp.componentInstance.testB).toBeInstanceOf(TestB);
         expect(cmp.componentInstance.testB.a.injector).toBe('standalone');
       });

    it('should not have access to the directive injector in a standalone injector from within a directive-level provider factory',
       () => {
         class TestA {
           constructor(public injector: string) {}
         }
         class TestB {
           constructor(public a: TestA|null) {}
         }

         function createTestB() {
           // Setup a standalone injector that provides `TestB` with an optional dependency of
           // `TestA`. Since `TestA` is not provided by the standalone injector it should resolve
           // to null; both the NgModule providers and the component-level providers should not
           // be considered.
           const injector = Injector.create({
             providers: [{provide: TestB, useClass: TestB, deps: [[TestA, new Optional()]]}],
             name: 'TestB',
           });
           return injector.get(TestB);
         }

         @Component({
           template: '',
           providers: [
             {provide: TestA, useFactory: () => new TestA('component'), deps: []},
             {provide: TestB, useFactory: createTestB},
           ],
         })
         class MyComp {
           constructor(public readonly testB: TestB) {}
         }

         TestBed.configureTestingModule({
           declarations: [MyComp],
           providers: [{provide: TestA, useFactory: () => new TestA('module'), deps: []}]
         });

         const cmp = TestBed.createComponent(MyComp);
         expect(cmp.componentInstance.testB).toBeInstanceOf(TestB);
         expect(cmp.componentInstance.testB.a).toBeNull();
       });

    it('should throw if directive tries to inject itself', () => {
      @Directive({selector: '[dirA]'})
      class DirectiveA {
        constructor(siblingDir: DirectiveA) {}
      }

      @Component({template: '<div dirA></div>'})
      class MyComp {
      }

      TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp]});
      expect(() => TestBed.createComponent(MyComp))
          .toThrowError(
              'NG0200: Circular dependency in DI detected for DirectiveA. Find more at https://angular.io/errors/NG0200');
    });

    describe('flags', () => {
      @Directive({selector: '[dirB]'})
      class DirectiveB {
        @Input('dirB') value = '';
      }

      describe('Optional', () => {
        @Directive({selector: '[dirA]'})
        class DirectiveA {
          constructor(@Optional() public dirB: DirectiveB) {}
        }

        it('should not throw if dependency is @Optional (module injector)', () => {
          @Component({template: '<div dirA></div>'})
          class MyComp {
            @ViewChild(DirectiveA) dirA!: DirectiveA;
          }

          TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp]});
          const fixture = TestBed.createComponent(MyComp);
          fixture.detectChanges();

          const dirA = fixture.componentInstance.dirA;
          expect(dirA.dirB).toBeNull();
        });

        it('should return null if @Optional dependency has @Self flag', () => {
          @Directive({selector: '[dirC]'})
          class DirectiveC {
            constructor(@Optional() @Self() public dirB: DirectiveB) {}
          }

          @Component({template: '<div dirC></div>'})
          class MyComp {
            @ViewChild(DirectiveC) dirC!: DirectiveC;
          }

          TestBed.configureTestingModule({declarations: [DirectiveC, MyComp]});
          const fixture = TestBed.createComponent(MyComp);
          fixture.detectChanges();

          const dirC = fixture.componentInstance.dirC;
          expect(dirC.dirB).toBeNull();
        });

        it('should not throw if dependency is @Optional but defined elsewhere', () => {
          @Directive({selector: '[dirC]'})
          class DirectiveC {
            constructor(@Optional() public dirB: DirectiveB) {}
          }

          @Component({template: '<div dirB></div><div dirC></div>'})
          class MyComp {
            @ViewChild(DirectiveC) dirC!: DirectiveC;
          }

          TestBed.configureTestingModule({declarations: [DirectiveB, DirectiveC, MyComp]});
          const fixture = TestBed.createComponent(MyComp);
          fixture.detectChanges();

          const dirC = fixture.componentInstance.dirC;
          expect(dirC.dirB).toBeNull();
        });

        it('should imply @Optional in presence of a default value', () => {
          const NON_EXISTING_PROVIDER = new InjectionToken<string>('non-existing');

          @Component({template: ''})
          class MyComp {
            value: string|undefined;
            constructor(injector: Injector) {
              this.value = injector.get(NON_EXISTING_PROVIDER, 'default', InjectFlags.Host);
            }
          }

          const injector = Injector.create({providers: []});
          expect(injector.get(NON_EXISTING_PROVIDER, 'default', InjectFlags.Host)).toBe('default');

          const fixture = TestBed.createComponent(MyComp);
          expect(fixture.componentInstance.value).toBe('default');
        });
      });

      it('should check only the current node with @Self', () => {
        @Directive({selector: '[dirA]'})
        class DirectiveA {
          constructor(@Self() public dirB: DirectiveB) {}
        }

        @Component({template: '<div dirB><div dirA></div></div>'})
        class MyComp {
        }
        TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp]});
        expect(() => TestBed.createComponent(MyComp))
            .toThrowError(/NG0201: No provider for DirectiveB found in NodeInjector/);
      });

      describe('SkipSelf', () => {
        describe('Injectors', () => {
          it('should support @SkipSelf when injecting Injectors', () => {
            @Component({
              selector: 'parent',
              template: '<child></child>',
              providers: [{
                provide: 'token',
                useValue: 'PARENT',
              }]
            })
            class ParentComponent {
            }

            @Component({
              selector: 'child',
              template: '...',
              providers: [{
                provide: 'token',
                useValue: 'CHILD',
              }]
            })
            class ChildComponent {
              constructor(public injector: Injector, @SkipSelf() public parentInjector: Injector) {}
            }

            TestBed.configureTestingModule({
              declarations: [ParentComponent, ChildComponent],
            });
            const fixture = TestBed.createComponent(ParentComponent);
            fixture.detectChanges();

            const childComponent =
                fixture.debugElement.query(By.directive(ChildComponent)).componentInstance;
            expect(childComponent.injector.get('token')).toBe('CHILD');
            expect(childComponent.parentInjector.get('token')).toBe('PARENT');
          });

          it('should lookup module injector in case @SkipSelf is used and no suitable Injector found in element injector tree',
             () => {
               let componentInjector: Injector;
               let moduleInjector: Injector;
               @Component({
                 selector: 'child',
                 template: '...',
                 providers: [{
                   provide: 'token',
                   useValue: 'CHILD',
                 }]
               })
               class MyComponent {
                 constructor(@SkipSelf() public injector: Injector) {
                   componentInjector = injector;
                 }
               }

               @NgModule({
                 declarations: [MyComponent],
                 providers: [{
                   provide: 'token',
                   useValue: 'NG_MODULE',
                 }]
               })
               class MyModule {
                 constructor(public injector: Injector) {
                   moduleInjector = injector;
                 }
               }

               TestBed.configureTestingModule({
                 imports: [MyModule],
               });
               const fixture = TestBed.createComponent(MyComponent);
               fixture.detectChanges();

               expect(componentInjector!.get('token')).toBe('NG_MODULE');
               expect(moduleInjector!.get('token')).toBe('NG_MODULE');
             });

          it('should respect @Host in case @SkipSelf is used and no suitable Injector found in element injector tree',
             () => {
               let componentInjector: Injector;
               let moduleInjector: Injector;
               @Component({
                 selector: 'child',
                 template: '...',
                 providers: [{
                   provide: 'token',
                   useValue: 'CHILD',
                 }]
               })
               class MyComponent {
                 constructor(@Host() @SkipSelf() public injector: Injector) {
                   componentInjector = injector;
                 }
               }

               @NgModule({
                 declarations: [MyComponent],
                 providers: [{
                   provide: 'token',
                   useValue: 'NG_MODULE',
                 }]
               })
               class MyModule {
                 constructor(public injector: Injector) {
                   moduleInjector = injector;
                 }
               }

               TestBed.configureTestingModule({
                 imports: [MyModule],
               });

               expect(() => TestBed.createComponent(MyComponent))
                   .toThrowError(/NG0201: No provider for Injector found in NodeInjector/);
             });

          it('should throw when injecting Injectors using @SkipSelf and @Host and no Injectors are available in a current view',
             () => {
               @Component({
                 selector: 'parent',
                 template: '<child></child>',
                 providers: [{
                   provide: 'token',
                   useValue: 'PARENT',
                 }]
               })
               class ParentComponent {
               }

               @Component({
                 selector: 'child',
                 template: '...',
                 providers: [{
                   provide: 'token',
                   useValue: 'CHILD',
                 }]
               })
               class ChildComponent {
                 constructor(@Host() @SkipSelf() public injector: Injector) {}
               }

               TestBed.configureTestingModule({
                 declarations: [ParentComponent, ChildComponent],
               });

               const expectedErrorMessage =
                   /NG0201: No provider for Injector found in NodeInjector/;
               expect(() => TestBed.createComponent(ParentComponent))
                   .toThrowError(expectedErrorMessage);
             });

          it('should not throw when injecting Injectors using @SkipSelf, @Host, and @Optional and no Injectors are available in a current view',
             () => {
               @Component({
                 selector: 'parent',
                 template: '<child></child>',
                 providers: [{
                   provide: 'token',
                   useValue: 'PARENT',
                 }]
               })
               class ParentComponent {
               }

               @Component({
                 selector: 'child',
                 template: '...',
                 providers: [{
                   provide: 'token',
                   useValue: 'CHILD',
                 }]
               })
               class ChildComponent {
                 constructor(@Host() @SkipSelf() @Optional() public injector: Injector) {}
               }

               TestBed.configureTestingModule({
                 declarations: [ParentComponent, ChildComponent],
               });

               const expectedErrorMessage =
                   /NG0201: No provider for Injector found in NodeInjector/;
               expect(() => TestBed.createComponent(ParentComponent))
                   .not.toThrowError(expectedErrorMessage);
             });
        });

        describe('ElementRef', () => {
          // While tokens like `ElementRef` make sense only in a context of a NodeInjector,
          // ViewEngine also used `ModuleInjector` tree to lookup such tokens. In Ivy we replicate
          // this behavior for now to avoid breaking changes.
          it('should lookup module injector in case @SkipSelf is used for `ElementRef` token and Component has no parent',
             () => {
               let componentElement: ElementRef;
               let moduleElement: ElementRef;
               @Component({template: '<div>component</div>'})
               class MyComponent {
                 constructor(@SkipSelf() public el: ElementRef) {
                   componentElement = el;
                 }
               }

               @NgModule({
                 declarations: [MyComponent],
                 providers: [{
                   provide: ElementRef,
                   useValue: {from: 'NG_MODULE'},
                 }]
               })
               class MyModule {
                 constructor(public el: ElementRef) {
                   moduleElement = el;
                 }
               }

               TestBed.configureTestingModule({
                 imports: [MyModule],
               });
               const fixture = TestBed.createComponent(MyComponent);
               fixture.detectChanges();

               expect((moduleElement! as any).from).toBe('NG_MODULE');
               expect((componentElement! as any).from).toBe('NG_MODULE');
             });

          it('should return host node when @SkipSelf is used for `ElementRef` token and Component has no parent node',
             () => {
               let parentElement: ElementRef;
               let componentElement: ElementRef;
               @Component({selector: 'child', template: '...'})
               class MyComponent {
                 constructor(@SkipSelf() public el: ElementRef) {
                   componentElement = el;
                 }
               }

               @Component({
                 template: '<child></child>',
               })
               class ParentComponent {
                 constructor(public el: ElementRef) {
                   parentElement = el;
                 }
               }

               TestBed.configureTestingModule({
                 imports: [CommonModule],
                 declarations: [ParentComponent, MyComponent],
               });
               const fixture = TestBed.createComponent(ParentComponent);
               fixture.detectChanges();

               expect(componentElement!).toEqual(parentElement!);
             });

          it('should @SkipSelf on child directive node when injecting ElementRef on nested parent directive',
             () => {
               let parentRef: ElementRef;
               let childRef: ElementRef;

               @Directive({selector: '[parent]'})
               class ParentDirective {
                 constructor(elementRef: ElementRef) {
                   parentRef = elementRef;
                 }
               }

               @Directive({selector: '[child]'})
               class ChildDirective {
                 constructor(@SkipSelf() elementRef: ElementRef) {
                   childRef = elementRef;
                 }
               }

               @Component({template: '<div parent>parent <span child>child</span></div>'})
               class MyComp {
               }

               TestBed.configureTestingModule(
                   {declarations: [ParentDirective, ChildDirective, MyComp]});
               const fixture = TestBed.createComponent(MyComp);
               fixture.detectChanges();

               // Assert against the `nativeElement` since Ivy always returns a new ElementRef.
               expect(childRef!.nativeElement).toBe(parentRef!.nativeElement);
               expect(childRef!.nativeElement.tagName).toBe('DIV');
             });
        });

        describe('@SkipSelf when parent contains embedded views', () => {
          it('should work for `ElementRef` token', () => {
            let requestedElementRef: ElementRef;
            @Component({
              selector: 'child',
              template: '...',
            })
            class ChildComponent {
              constructor(@SkipSelf() public elementRef: ElementRef) {
                requestedElementRef = elementRef;
              }
            }
            @Component({
              selector: 'root',
              template: '<div><child *ngIf="true"></child></div>',
            })
            class ParentComponent {
            }

            TestBed.configureTestingModule({
              imports: [CommonModule],
              declarations: [ParentComponent, ChildComponent],
            });
            const fixture = TestBed.createComponent(ParentComponent);
            fixture.detectChanges();

            expect(requestedElementRef!.nativeElement).toEqual(fixture.nativeElement.firstChild);
            expect(requestedElementRef!.nativeElement.tagName).toEqual('DIV');
          });

          it('should work for `ElementRef` token with expanded *ngIf', () => {
            let requestedElementRef: ElementRef;
            @Component({
              selector: 'child',
              template: '...',
            })
            class ChildComponent {
              constructor(@SkipSelf() public elementRef: ElementRef) {
                requestedElementRef = elementRef;
              }
            }
            @Component({
              selector: 'root',
              template: '<div><ng-template [ngIf]="true"><child></child></ng-template></div>',
            })
            class ParentComponent {
            }

            TestBed.configureTestingModule({
              imports: [CommonModule],
              declarations: [ParentComponent, ChildComponent],
            });
            const fixture = TestBed.createComponent(ParentComponent);
            fixture.detectChanges();

            expect(requestedElementRef!.nativeElement).toEqual(fixture.nativeElement.firstChild);
            expect(requestedElementRef!.nativeElement.tagName).toEqual('DIV');
          });

          it('should work for `ViewContainerRef` token', () => {
            let requestedRef: ViewContainerRef;
            @Component({
              selector: 'child',
              template: '...',
            })
            class ChildComponent {
              constructor(@SkipSelf() public ref: ViewContainerRef) {
                requestedRef = ref;
              }
            }

            @Component({
              selector: 'root',
              template: '<div><child *ngIf="true"></child></div>',
            })
            class ParentComponent {
            }

            TestBed.configureTestingModule({
              imports: [CommonModule],
              declarations: [ParentComponent, ChildComponent],
            });
            const fixture = TestBed.createComponent(ParentComponent);
            fixture.detectChanges();

            expect(requestedRef!.element.nativeElement).toBe(fixture.nativeElement.firstChild);
            expect(requestedRef!.element.nativeElement.tagName).toBe('DIV');
          });

          it('should work for `ChangeDetectorRef` token', () => {
            let requestedChangeDetectorRef: ChangeDetectorRef;
            @Component({
              selector: 'child',
              template: '...',
            })
            class ChildComponent {
              constructor(@SkipSelf() public changeDetectorRef: ChangeDetectorRef) {
                requestedChangeDetectorRef = changeDetectorRef;
              }
            }

            @Component({
              selector: 'root',
              template: '<child *ngIf="true"></child>',
            })
            class ParentComponent {
            }

            TestBed.configureTestingModule({
              imports: [CommonModule],
              declarations: [ParentComponent, ChildComponent],
            });
            const fixture = TestBed.createComponent(ParentComponent);
            fixture.detectChanges();

            const {context} = requestedChangeDetectorRef! as ViewRefInternal<ParentComponent>;
            expect(context).toBe(fixture.componentInstance);
          });

          // this works consistently between VE and Ivy
          it('should work for Injectors', () => {
            let childComponentInjector: Injector;
            let parentComponentInjector: Injector;
            @Component({
              selector: 'parent',
              template: '<child *ngIf="true"></child>',
              providers: [{
                provide: 'token',
                useValue: 'PARENT',
              }]
            })
            class ParentComponent {
              constructor(public injector: Injector) {
                parentComponentInjector = injector;
              }
            }

            @Component({
              selector: 'child',
              template: '...',
              providers: [{
                provide: 'token',
                useValue: 'CHILD',
              }]
            })
            class ChildComponent {
              constructor(@SkipSelf() public injector: Injector) {
                childComponentInjector = injector;
              }
            }

            TestBed.configureTestingModule({
              declarations: [ParentComponent, ChildComponent],
            });
            const fixture = TestBed.createComponent(ParentComponent);
            fixture.detectChanges();

            expect(childComponentInjector!.get('token'))
                .toBe(parentComponentInjector!.get('token'));
          });

          it('should work for Injectors with expanded *ngIf', () => {
            let childComponentInjector: Injector;
            let parentComponentInjector: Injector;
            @Component({
              selector: 'parent',
              template: '<ng-template [ngIf]="true"><child></child></ng-template>',
              providers: [{
                provide: 'token',
                useValue: 'PARENT',
              }]
            })
            class ParentComponent {
              constructor(public injector: Injector) {
                parentComponentInjector = injector;
              }
            }

            @Component({
              selector: 'child',
              template: '...',
              providers: [{
                provide: 'token',
                useValue: 'CHILD',
              }]
            })
            class ChildComponent {
              constructor(@SkipSelf() public injector: Injector) {
                childComponentInjector = injector;
              }
            }

            TestBed.configureTestingModule({
              declarations: [ParentComponent, ChildComponent],
            });
            const fixture = TestBed.createComponent(ParentComponent);
            fixture.detectChanges();

            expect(childComponentInjector!.get('token'))
                .toBe(parentComponentInjector!.get('token'));
          });
        });

        describe('TemplateRef', () => {
          // SkipSelf doesn't make sense to use with TemplateRef since you
          // can't inject TemplateRef on a regular element and you can initialize
          // a child component on a nested `<ng-template>` only when a component/directive
          // on a parent `<ng-template>` is initialized.
          it('should throw when using @SkipSelf for TemplateRef', () => {
            @Directive({selector: '[dir]', exportAs: 'dir'})
            class MyDir {
              constructor(@SkipSelf() public templateRef: TemplateRef<any>) {}
            }

            @Component({selector: '[child]', template: '<ng-template dir></ng-template>'})
            class ChildComp {
              constructor(public templateRef: TemplateRef<any>) {}
              @ViewChild(MyDir) directive!: MyDir;
            }

            @Component({
              selector: 'root',
              template: '<div child></div>',
            })
            class MyComp {
              @ViewChild(ChildComp) child!: ChildComp;
            }

            TestBed.configureTestingModule({
              imports: [CommonModule],
              declarations: [MyDir, ChildComp, MyComp],
            });
            const expectedErrorMessage = /NG0201: No provider for TemplateRef found/;
            expect(() => {
              const fixture = TestBed.createComponent(MyComp);
              fixture.detectChanges();
            }).toThrowError(expectedErrorMessage);
          });

          it('should throw when SkipSelf and no parent TemplateRef', () => {
            @Directive({selector: '[dirA]', exportAs: 'dirA'})
            class DirA {
              constructor(@SkipSelf() public templateRef: TemplateRef<any>) {}
            }

            @Component({
              selector: 'root',
              template: '<ng-template dirA></ng-template>',
            })
            class MyComp {
            }

            TestBed.configureTestingModule({
              imports: [CommonModule],
              declarations: [DirA, MyComp],
            });
            const expectedErrorMessage = /NG0201: No provider for TemplateRef found/;
            expect(() => {
              const fixture = TestBed.createComponent(MyComp);
              fixture.detectChanges();
            }).toThrowError(expectedErrorMessage);
          });

          it('should not throw when SkipSelf and Optional', () => {
            let directiveTemplateRef;
            @Directive({selector: '[dirA]', exportAs: 'dirA'})
            class DirA {
              constructor(@SkipSelf() @Optional() templateRef: TemplateRef<any>) {
                directiveTemplateRef = templateRef;
              }
            }

            @Component({
              selector: 'root',
              template: '<ng-template dirA></ng-template>',
            })
            class MyComp {
            }

            TestBed.configureTestingModule({
              imports: [CommonModule],
              declarations: [DirA, MyComp],
            });

            const fixture = TestBed.createComponent(MyComp);
            fixture.detectChanges();

            expect(directiveTemplateRef).toBeNull();
          });

          it('should not throw when SkipSelf, Optional, and Host', () => {
            @Directive({selector: '[dirA]', exportAs: 'dirA'})
            class DirA {
              constructor(@SkipSelf() @Optional() @Host() public templateRef: TemplateRef<any>) {}
            }

            @Component({
              selector: 'root',
              template: '<ng-template dirA></ng-template>',
            })
            class MyComp {
            }

            TestBed.configureTestingModule({
              imports: [CommonModule],
              declarations: [DirA, MyComp],
            });

            expect(() => TestBed.createComponent(MyComp)).not.toThrowError();
          });
        });

        describe('ViewContainerRef', () => {
          it('should support @SkipSelf when injecting ViewContainerRef', () => {
            let parentViewContainer: ViewContainerRef;
            let childViewContainer: ViewContainerRef;

            @Directive({selector: '[parent]'})
            class ParentDirective {
              constructor(vc: ViewContainerRef) {
                parentViewContainer = vc;
              }
            }

            @Directive({selector: '[child]'})
            class ChildDirective {
              constructor(@SkipSelf() vc: ViewContainerRef) {
                childViewContainer = vc;
              }
            }

            @Component({template: '<div parent>parent <span child>child</span></div>'})
            class MyComp {
            }

            TestBed.configureTestingModule(
                {declarations: [ParentDirective, ChildDirective, MyComp]});
            const fixture = TestBed.createComponent(MyComp);
            fixture.detectChanges();

            // Assert against the `element` since Ivy always returns a new ViewContainerRef.
            expect(childViewContainer!.element.nativeElement)
                .toBe(parentViewContainer!.element.nativeElement);
            expect(parentViewContainer!.element.nativeElement.tagName).toBe('DIV');
          });

          it('should get ViewContainerRef using @SkipSelf and @Host', () => {
            let parentViewContainer: ViewContainerRef;
            let childViewContainer: ViewContainerRef;

            @Directive({selector: '[parent]'})
            class ParentDirective {
              constructor(vc: ViewContainerRef) {
                parentViewContainer = vc;
              }
            }

            @Directive({selector: '[child]'})
            class ChildDirective {
              constructor(@SkipSelf() @Host() vc: ViewContainerRef) {
                childViewContainer = vc;
              }
            }

            @Component({template: '<div parent>parent <span child>child</span></div>'})
            class MyComp {
            }

            TestBed.configureTestingModule(
                {declarations: [ParentDirective, ChildDirective, MyComp]});

            const fixture = TestBed.createComponent(MyComp);
            fixture.detectChanges();

            expect(childViewContainer!.element.nativeElement)
                .toBe(parentViewContainer!.element.nativeElement);
            expect(parentViewContainer!.element.nativeElement.tagName).toBe('DIV');
          });

          it('should get ViewContainerRef using @SkipSelf and @Host on parent', () => {
            let parentViewContainer: ViewContainerRef;

            @Directive({selector: '[parent]'})
            class ParentDirective {
              constructor(@SkipSelf() vc: ViewContainerRef) {
                parentViewContainer = vc;
              }
            }

            @Component({template: '<div parent>parent</div>'})
            class MyComp {
            }

            TestBed.configureTestingModule({declarations: [ParentDirective, MyComp]});

            const fixture = TestBed.createComponent(MyComp);
            fixture.detectChanges();

            expect(parentViewContainer!.element.nativeElement.tagName).toBe('DIV');
          });

          it('should throw when injecting ViewContainerRef using @SkipSelf and no ViewContainerRef are available in a current view',
             () => {
               @Component({template: '<span>component</span>'})
               class MyComp {
                 constructor(@SkipSelf() vc: ViewContainerRef) {}
               }

               TestBed.configureTestingModule({declarations: [MyComp]});

               expect(() => TestBed.createComponent(MyComp))
                   .toThrowError(/No provider for ViewContainerRef/);
             });
        });

        describe('ChangeDetectorRef', () => {
          it('should support @SkipSelf when injecting ChangeDetectorRef', () => {
            let parentRef: ChangeDetectorRef|undefined;
            let childRef: ChangeDetectorRef|undefined;

            @Directive({selector: '[parent]'})
            class ParentDirective {
              constructor(cdr: ChangeDetectorRef) {
                parentRef = cdr;
              }
            }

            @Directive({selector: '[child]'})
            class ChildDirective {
              constructor(@SkipSelf() cdr: ChangeDetectorRef) {
                childRef = cdr;
              }
            }

            @Component({template: '<div parent>parent <span child>child</span></div>'})
            class MyComp {
            }

            TestBed.configureTestingModule(
                {declarations: [ParentDirective, ChildDirective, MyComp]});
            const fixture = TestBed.createComponent(MyComp);
            fixture.detectChanges();

            // Assert against the `rootNodes` since Ivy always returns a new ChangeDetectorRef.
            expect((parentRef as ViewRefInternal<any>).rootNodes)
                .toEqual((childRef as ViewRefInternal<any>).rootNodes);
          });

          it('should inject host component ChangeDetectorRef when @SkipSelf', () => {
            let childRef: ChangeDetectorRef|undefined;

            @Component({selector: 'child', template: '...'})
            class ChildComp {
              constructor(@SkipSelf() cdr: ChangeDetectorRef) {
                childRef = cdr;
              }
            }

            @Component({template: '<div><child></child></div>'})
            class MyComp {
              constructor(public cdr: ChangeDetectorRef) {}
            }

            TestBed.configureTestingModule({declarations: [ChildComp, MyComp]});
            const fixture = TestBed.createComponent(MyComp);
            fixture.detectChanges();

            // Assert against the `rootNodes` since Ivy always returns a new ChangeDetectorRef.
            expect((childRef as ViewRefInternal<any>).rootNodes)
                .toEqual((fixture.componentInstance.cdr as ViewRefInternal<any>).rootNodes);
          });

          it('should throw when ChangeDetectorRef and @SkipSelf and not found', () => {
            @Component({template: '<div></div>'})
            class MyComponent {
              constructor(@SkipSelf() public injector: ChangeDetectorRef) {}
            }

            @NgModule({
              declarations: [MyComponent],
            })
            class MyModule {
            }

            TestBed.configureTestingModule({
              imports: [MyModule],
            });

            expect(() => TestBed.createComponent(MyComponent))
                .toThrowError(/No provider for ChangeDetectorRef/);
          });

          it('should lookup module injector in case @SkipSelf is used for `ChangeDetectorRef` token and Component has no parent',
             () => {
               let componentCDR: ChangeDetectorRef;
               let moduleCDR: ChangeDetectorRef;
               @Component({selector: 'child', template: '...'})
               class MyComponent {
                 constructor(@SkipSelf() public injector: ChangeDetectorRef) {
                   componentCDR = injector;
                 }
               }

               @NgModule({
                 declarations: [MyComponent],
                 providers: [{
                   provide: ChangeDetectorRef,
                   useValue: {from: 'NG_MODULE'},
                 }]
               })
               class MyModule {
                 constructor(public injector: ChangeDetectorRef) {
                   moduleCDR = injector;
                 }
               }

               TestBed.configureTestingModule({
                 imports: [MyModule],
               });
               const fixture = TestBed.createComponent(MyComponent);
               fixture.detectChanges();

               expect((moduleCDR! as any).from).toBe('NG_MODULE');
               expect((componentCDR! as any).from).toBe('NG_MODULE');
             });
        });

        describe('viewProviders', () => {
          it('should support @SkipSelf when using viewProviders', () => {
            @Component({
              selector: 'child',
              template: '{{ blah | json }}<br />{{ foo | json }}<br />{{ bar | json }}',
              providers: [{provide: 'Blah', useValue: 'Blah as Provider'}],
              viewProviders: [
                {provide: 'Foo', useValue: 'Foo as ViewProvider'},
                {provide: 'Bar', useValue: 'Bar as ViewProvider'},
              ]
            })
            class Child {
              constructor(
                  @Inject('Blah') public blah: String,
                  @Inject('Foo') public foo: String,
                  @SkipSelf() @Inject('Bar') public bar: String,
              ) {}
            }

            @Component({
              selector: 'parent',
              template: '<ng-content></ng-content>',
              providers: [
                {provide: 'Blah', useValue: 'Blah as provider'},
                {provide: 'Bar', useValue: 'Bar as Provider'},
              ],
              viewProviders: [
                {provide: 'Foo', useValue: 'Foo as ViewProvider'},
                {provide: 'Bar', useValue: 'Bar as ViewProvider'},
              ]
            })
            class Parent {
            }

            @Component({selector: 'my-app', template: '<parent><child></child></parent>'})
            class MyApp {
              @ViewChild(Parent) parent!: Parent;
              @ViewChild(Child) child!: Child;
            }

            TestBed.configureTestingModule({declarations: [Child, Parent, MyApp]});
            const fixture = TestBed.createComponent(MyApp);
            fixture.detectChanges();

            const child = fixture.componentInstance.child;
            expect(child.bar).toBe('Bar as Provider');
          });

          it('should throw when @SkipSelf and no accessible viewProvider', () => {
            @Component({
              selector: 'child',
              template: '{{ blah | json }}<br />{{ foo | json }}<br />{{ bar | json }}',
              providers: [{provide: 'Blah', useValue: 'Blah as Provider'}],
              viewProviders: [
                {provide: 'Foo', useValue: 'Foo as ViewProvider'},
                {provide: 'Bar', useValue: 'Bar as ViewProvider'},
              ]
            })
            class Child {
              constructor(
                  @Inject('Blah') public blah: String,
                  @Inject('Foo') public foo: String,
                  @SkipSelf() @Inject('Bar') public bar: String,
              ) {}
            }

            @Component({
              selector: 'parent',
              template: '<ng-content></ng-content>',
              providers: [{provide: 'Blah', useValue: 'Blah as provider'}],
              viewProviders: [
                {provide: 'Foo', useValue: 'Foo as ViewProvider'},
                {provide: 'Bar', useValue: 'Bar as ViewProvider'},
              ]
            })
            class Parent {
            }

            @Component({selector: 'my-app', template: '<parent><child></child></parent>'})
            class MyApp {
            }

            TestBed.configureTestingModule({declarations: [Child, Parent, MyApp]});

            expect(() => TestBed.createComponent(MyApp)).toThrowError(/No provider for Bar/);
          });

          it('should not throw when @SkipSelf and @Optional with no accessible viewProvider',
             () => {
               @Component({
                 selector: 'child',
                 template: '{{ blah | json }}<br />{{ foo | json }}<br />{{ bar | json }}',
                 providers: [{provide: 'Blah', useValue: 'Blah as Provider'}],
                 viewProviders: [
                   {provide: 'Foo', useValue: 'Foo as ViewProvider'},
                   {provide: 'Bar', useValue: 'Bar as ViewProvider'},
                 ]
               })
               class Child {
                 constructor(
                     @Inject('Blah') public blah: String,
                     @Inject('Foo') public foo: String,
                     @SkipSelf() @Optional() @Inject('Bar') public bar: String,
                 ) {}
               }

               @Component({
                 selector: 'parent',
                 template: '<ng-content></ng-content>',
                 providers: [{provide: 'Blah', useValue: 'Blah as provider'}],
                 viewProviders: [
                   {provide: 'Foo', useValue: 'Foo as ViewProvider'},
                   {provide: 'Bar', useValue: 'Bar as ViewProvider'},
                 ]
               })
               class Parent {
               }

               @Component({selector: 'my-app', template: '<parent><child></child></parent>'})
               class MyApp {
               }

               TestBed.configureTestingModule({declarations: [Child, Parent, MyApp]});

               expect(() => TestBed.createComponent(MyApp)).not.toThrowError(/No provider for Bar/);
             });
        });
      });

      describe('@Host', () => {
        @Directive({selector: '[dirA]'})
        class DirectiveA {
          constructor(@Host() public dirB: DirectiveB) {}
        }

        @Directive({selector: '[dirString]'})
        class DirectiveString {
          constructor(@Host() public s: String) {}
        }

        it('should find viewProviders on the host itself', () => {
          @Component({
            selector: 'my-comp',
            template: '<div dirString></div>',
            viewProviders: [{provide: String, useValue: 'Foo'}]
          })
          class MyComp {
            @ViewChild(DirectiveString) dirString!: DirectiveString;
          }

          @Component({template: '<my-comp></my-comp>'})
          class MyApp {
            @ViewChild(MyComp) myComp!: MyComp;
          }

          TestBed.configureTestingModule({declarations: [DirectiveString, MyComp, MyApp]});
          const fixture = TestBed.createComponent(MyApp);
          fixture.detectChanges();

          const dirString = fixture.componentInstance.myComp.dirString;
          expect(dirString.s).toBe('Foo');
        });

        it('should not find providers on the host itself', () => {
          @Component({
            selector: 'my-comp',
            template: '<div dirString></div>',
            providers: [{provide: String, useValue: 'Foo'}]
          })
          class MyComp {
          }

          @Component({template: '<my-comp></my-comp>'})
          class MyApp {
          }

          TestBed.configureTestingModule({declarations: [DirectiveString, MyComp, MyApp]});
          expect(() => TestBed.createComponent(MyApp))
              .toThrowError(
                  'NG0201: No provider for String found in NodeInjector. Find more at https://angular.io/errors/NG0201');
        });

        it('should not find other directives on the host itself', () => {
          @Component({selector: 'my-comp', template: '<div dirA></div>'})
          class MyComp {
          }

          @Component({template: '<my-comp dirB></my-comp>'})
          class MyApp {
          }

          TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp, MyApp]});
          expect(() => TestBed.createComponent(MyApp))
              .toThrowError(/NG0201: No provider for DirectiveB found in NodeInjector/);
        });

        it('should not find providers on the host itself if in inline view', () => {
          @Component({
            selector: 'my-comp',
            template: '<ng-container *ngIf="showing"><div dirA></div></ng-container>'
          })
          class MyComp {
            showing = false;
          }

          @Component({template: '<my-comp dirB></my-comp>'})
          class MyApp {
            @ViewChild(MyComp) myComp!: MyComp;
          }

          TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyComp, MyApp]});
          const fixture = TestBed.createComponent(MyApp);
          fixture.detectChanges();
          expect(() => {
            fixture.componentInstance.myComp.showing = true;
            fixture.detectChanges();
          }).toThrowError(/NG0201: No provider for DirectiveB found in NodeInjector/);
        });

        it('should find providers across embedded views if not passing component boundary', () => {
          @Component({template: '<div dirB><div *ngIf="showing" dirA></div></div>'})
          class MyApp {
            showing = false;
            @ViewChild(DirectiveA) dirA!: DirectiveA;
            @ViewChild(DirectiveB) dirB!: DirectiveB;
          }

          TestBed.configureTestingModule({declarations: [DirectiveA, DirectiveB, MyApp]});
          const fixture = TestBed.createComponent(MyApp);
          fixture.detectChanges();
          fixture.componentInstance.showing = true;
          fixture.detectChanges();

          const dirA = fixture.componentInstance.dirA;
          const dirB = fixture.componentInstance.dirB;
          expect(dirA.dirB).toBe(dirB);
        });

        it('should not find component above the host', () => {
          @Component({template: '<my-comp></my-comp>'})
          class MyApp {
          }

          @Directive({selector: '[dirComp]'})
          class DirectiveComp {
            constructor(@Host() public comp: MyApp) {}
          }

          @Component({selector: 'my-comp', template: '<div dirComp></div>'})
          class MyComp {
          }

          TestBed.configureTestingModule({declarations: [DirectiveComp, MyComp, MyApp]});
          expect(() => TestBed.createComponent(MyApp))
              .toThrowError(
                  'NG0201: No provider for MyApp found in NodeInjector. Find more at https://angular.io/errors/NG0201');
        });

        describe('regression', () => {
          // based on https://stackblitz.com/edit/angular-riss8k?file=src/app/app.component.ts
          it('should allow directives with Host flag to inject view providers from containing component',
             () => {
               class ControlContainer {}
               let controlContainers: ControlContainer[] = [];
               let injectedControlContainer: ControlContainer|null = null;

               @Directive({
                 selector: '[group]',
                 providers: [{provide: ControlContainer, useExisting: GroupDirective}]
               })
               class GroupDirective {
                 constructor() {
                   controlContainers.push(this);
                 }
               }

               @Directive({selector: '[control]'})
               class ControlDirective {
                 constructor(@Host() @SkipSelf() @Inject(ControlContainer) parent:
                                 ControlContainer) {
                   injectedControlContainer = parent;
                 }
               }

               @Component({
                 selector: 'my-comp',
                 template: '<input control>',
                 viewProviders: [{provide: ControlContainer, useExisting: GroupDirective}]
               })
               class MyComp {
               }

               @Component({
                 template: `
                   <div group>
                     <my-comp></my-comp>
                   </div>
                 `
               })
               class MyApp {
               }

               TestBed.configureTestingModule(
                   {declarations: [GroupDirective, ControlDirective, MyComp, MyApp]});
               const fixture = TestBed.createComponent(MyApp);
               expect(fixture.nativeElement.innerHTML)
                   .toBe('<div group=""><my-comp><input control=""></my-comp></div>');
               expect(controlContainers).toEqual([injectedControlContainer!]);
             });
        });
      });

      describe('`InjectFlags` support in NodeInjector', () => {
        it('should support Optional flag in NodeInjector', () => {
          const NON_EXISTING_PROVIDER = new InjectionToken<string>('non-existing');
          @Component({template: '...'})
          class MyComp {
            tokenViaInjector = this.injector.get(NON_EXISTING_PROVIDER, null, InjectFlags.Optional);
            constructor(
                public injector: Injector,
                @Inject(NON_EXISTING_PROVIDER) @Optional() public tokenViaConstructor: string) {}
          }
          TestBed.configureTestingModule({declarations: [MyComp]});
          const fixture = TestBed.createComponent(MyComp);
          fixture.detectChanges();
          expect(fixture.componentInstance.tokenViaInjector).toBe(null);
          expect(fixture.componentInstance.tokenViaInjector)
              .toBe(fixture.componentInstance.tokenViaConstructor);
        });
        it('should support SkipSelf flag in NodeInjector', () => {
          const TOKEN = new InjectionToken<string>('token');
          @Component({
            selector: 'parent',
            template: '<child></child>',
            providers: [{
              provide: TOKEN,
              useValue: 'PARENT',
            }]
          })
          class ParentComponent {
          }

          @Component({
            selector: 'child',
            template: '...',
            providers: [{
              provide: TOKEN,
              useValue: 'CHILD',
            }]
          })
          class ChildComponent {
            tokenViaInjector = this.injector.get(TOKEN, null, InjectFlags.SkipSelf);
            constructor(
                public injector: Injector,
                @Inject(TOKEN) @SkipSelf() public tokenViaConstructor: string) {}
          }

          TestBed.configureTestingModule({
            declarations: [ParentComponent, ChildComponent],
          });
          const fixture = TestBed.createComponent(ParentComponent);
          fixture.detectChanges();

          const childComponent =
              fixture.debugElement.query(By.directive(ChildComponent)).componentInstance;
          expect(childComponent.tokenViaInjector).toBe('PARENT');
          expect(childComponent.tokenViaConstructor).toBe(childComponent.tokenViaInjector);
        });
        it('should support Host flag in NodeInjector', () => {
          const TOKEN = new InjectionToken<string>('token');
          @Directive({selector: '[dirString]'})
          class DirectiveString {
            tokenViaInjector = this.injector.get(TOKEN, null, InjectFlags.Host);
            constructor(
                public injector: Injector,
                @Inject(TOKEN) @Host() public tokenViaConstructor: string) {}
          }

          @Component({
            template: '<div dirString></div>',
            viewProviders: [{provide: TOKEN, useValue: 'Foo'}]
          })
          class MyComp {
            @ViewChild(DirectiveString) dirString!: DirectiveString;
          }

          TestBed.configureTestingModule({declarations: [DirectiveString, MyComp]});
          const fixture = TestBed.createComponent(MyComp);
          fixture.detectChanges();

          const dirString = fixture.componentInstance.dirString;
          expect(dirString.tokenViaConstructor).toBe('Foo');
          expect(dirString.tokenViaConstructor).toBe(dirString.tokenViaInjector!);
        });
        it('should support multiple flags in NodeInjector', () => {
          @Directive({selector: '[dirA]'})
          class DirectiveA {
          }
          @Directive({selector: '[dirB]'})
          class DirectiveB {
            public tokenSelfViaInjector =
                this.injector.get(DirectiveA, null, InjectFlags.Self|InjectFlags.Optional);
            public tokenHostViaInjector =
                this.injector.get(DirectiveA, null, InjectFlags.Host|InjectFlags.Optional);
            constructor(
                public injector: Injector,
                @Inject(DirectiveA) @Self() @Optional() public tokenSelfViaConstructor: DirectiveA,
                @Inject(DirectiveA) @Host() @Optional() public tokenHostViaConstructor:
                    DirectiveA) {}
          }

          @Component({template: '<div dirB></div>'})
          class MyComp {
            @ViewChild(DirectiveB) dirB!: DirectiveB;
          }

          TestBed.configureTestingModule({declarations: [DirectiveB, MyComp]});
          const fixture = TestBed.createComponent(MyComp);
          fixture.detectChanges();

          const dirB = fixture.componentInstance.dirB;
          expect(dirB.tokenSelfViaInjector).toBeNull();
          expect(dirB.tokenSelfViaInjector).toBe(dirB.tokenSelfViaConstructor);
          expect(dirB.tokenHostViaInjector).toBeNull();
          expect(dirB.tokenHostViaInjector).toBe(dirB.tokenHostViaConstructor);
        });
      });
    });
  });

  describe('Tree shakable injectors', () => {
    it('should support tree shakable injectors scopes', () => {
      @Injectable({providedIn: 'any'})
      class AnyService {
        constructor(public injector: Injector) {}
      }

      @Injectable({providedIn: 'root'})
      class RootService {
        constructor(public injector: Injector) {}
      }

      @Injectable({providedIn: 'platform'})
      class PlatformService {
        constructor(public injector: Injector) {}
      }

      const testBedInjector: Injector = TestBed.get(Injector);
      const childInjector = Injector.create([], testBedInjector);

      const anyService = childInjector.get(AnyService);
      expect(anyService.injector).toBe(childInjector);

      const rootService = childInjector.get(RootService);
      expect(rootService.injector.get(ɵINJECTOR_SCOPE)).toBe('root');

      const platformService = childInjector.get(PlatformService);
      expect(platformService.injector.get(ɵINJECTOR_SCOPE)).toBe('platform');
    });

    it('should create a provider that uses `forwardRef` inside `providedIn`', () => {
      @Injectable()
      class ProviderDep {
        getNumber() {
          return 3;
        }
      }

      @Injectable({providedIn: forwardRef(() => Module)})
      class Provider {
        constructor(private _dep: ProviderDep) {}
        value = this._dep.getNumber() + 2;
      }

      @Component({template: ''})
      class Comp {
        constructor(public provider: Provider) {}
      }

      @NgModule({declarations: [Comp], exports: [Comp], providers: [ProviderDep]})
      class Module {
      }

      TestBed.configureTestingModule({imports: [Module]});
      const fixture = TestBed.createComponent(Comp);
      expect(fixture.componentInstance.provider.value).toBe(5);
    });
  });

  describe('service injection', () => {
    it('should create instance even when no injector present', () => {
      @Injectable({providedIn: 'root'})
      class MyService {
        value = 'MyService';
      }
      @Component({template: '<div>{{myService.value}}</div>'})
      class MyComp {
        constructor(public myService: MyService) {}
      }
      TestBed.configureTestingModule({declarations: [MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      const divElement = fixture.nativeElement.querySelector('div');
      expect(divElement.textContent).toEqual('MyService');
    });

    it('should support sub-classes with no @Injectable decorator', () => {
      @Injectable()
      class Dependency {
      }

      @Injectable()
      class SuperClass {
        constructor(public dep: Dependency) {}
      }

      // Note, no @Injectable decorators for these two classes
      class SubClass extends SuperClass {}
      class SubSubClass extends SubClass {}

      @Component({template: ''})
      class MyComp {
        constructor(public myService: SuperClass) {}
      }
      TestBed.configureTestingModule({
        declarations: [MyComp],
        providers: [{provide: SuperClass, useClass: SubSubClass}, Dependency]
      });

      const warnSpy = spyOn(console, 'warn');
      const fixture = TestBed.createComponent(MyComp);
      expect(fixture.componentInstance.myService.dep instanceof Dependency).toBe(true);

      expect(warnSpy).toHaveBeenCalledWith(
          `DEPRECATED: DI is instantiating a token "SubSubClass" that inherits its @Injectable decorator but does not provide one itself.\n` +
          `This will become an error in a future version of Angular. Please add @Injectable() to the "SubSubClass" class.`);
    });

    it('should instantiate correct class when undecorated class extends an injectable', () => {
      @Injectable()
      class MyService {
        id = 1;
      }

      class MyRootService extends MyService {
        override id = 2;
      }

      @Component({template: ''})
      class App {
      }

      TestBed.configureTestingModule({declarations: [App], providers: [MyRootService]});
      const warnSpy = spyOn(console, 'warn');
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      const provider = TestBed.inject(MyRootService);

      expect(provider instanceof MyRootService).toBe(true);
      expect(provider.id).toBe(2);

      expect(warnSpy).toHaveBeenCalledWith(
          `DEPRECATED: DI is instantiating a token "MyRootService" that inherits its @Injectable decorator but does not provide one itself.\n` +
          `This will become an error in a future version of Angular. Please add @Injectable() to the "MyRootService" class.`);
    });

    it('should inject services in constructor with overloads', () => {
      @Injectable({providedIn: 'root'})
      class MyService {
      }

      @Injectable({providedIn: 'root'})
      class MyOtherService {
      }

      @Component({template: ''})
      class MyComp {
        constructor(myService: MyService);
        constructor(
            public myService: MyService, @Optional() public myOtherService?: MyOtherService) {}
      }
      TestBed.configureTestingModule({declarations: [MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      expect(fixture.componentInstance.myService instanceof MyService).toBe(true);
      expect(fixture.componentInstance.myOtherService instanceof MyOtherService).toBe(true);
    });
  });

  describe('service injection with useClass', () => {
    @Injectable({providedIn: 'root'})
    class BarServiceDep {
      name = 'BarServiceDep';
    }

    @Injectable({providedIn: 'root'})
    class BarService {
      constructor(public dep: BarServiceDep) {}
      getMessage() {
        return 'bar';
      }
    }

    @Injectable({providedIn: 'root'})
    class FooServiceDep {
      name = 'FooServiceDep';
    }

    @Injectable({providedIn: 'root', useClass: BarService})
    class FooService {
      constructor(public dep: FooServiceDep) {}
      getMessage() {
        return 'foo';
      }
    }

    it('should use @Injectable useClass config when token is not provided', () => {
      let provider: FooService|BarService;

      @Component({template: ''})
      class App {
        constructor(service: FooService) {
          provider = service;
        }
      }

      TestBed.configureTestingModule({declarations: [App]});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      expect(provider!.getMessage()).toBe('bar');
      expect(provider!.dep.name).toBe('BarServiceDep');
    });

    it('should use constructor config directly when token is explicitly provided via useClass',
       () => {
         let provider: FooService|BarService;

         @Component({template: ''})
         class App {
           constructor(service: FooService) {
             provider = service;
           }
         }

         TestBed.configureTestingModule(
             {declarations: [App], providers: [{provide: FooService, useClass: FooService}]});
         const fixture = TestBed.createComponent(App);
         fixture.detectChanges();

         expect(provider!.getMessage()).toBe('foo');
       });


    it('should inject correct provider when re-providing an injectable that has useClass', () => {
      let directProvider: FooService|BarService;
      let overriddenProvider: FooService|BarService;

      @Component({template: ''})
      class App {
        constructor(@Inject('stringToken') overriddenService: FooService, service: FooService) {
          overriddenProvider = overriddenService;
          directProvider = service;
        }
      }

      TestBed.configureTestingModule(
          {declarations: [App], providers: [{provide: 'stringToken', useClass: FooService}]});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      expect(directProvider!.getMessage()).toBe('bar');
      expect(overriddenProvider!.getMessage()).toBe('foo');
      expect(directProvider!.dep.name).toBe('BarServiceDep');
      expect(overriddenProvider!.dep.name).toBe('FooServiceDep');
    });

    it('should use constructor config directly when token is explicitly provided as a type provider',
       () => {
         let provider: FooService|BarService;

         @Component({template: ''})
         class App {
           constructor(service: FooService) {
             provider = service;
           }
         }

         TestBed.configureTestingModule({declarations: [App], providers: [FooService]});
         const fixture = TestBed.createComponent(App);
         fixture.detectChanges();

         expect(provider!.getMessage()).toBe('foo');
         expect(provider!.dep.name).toBe('FooServiceDep');
       });
  });

  describe('inject', () => {
    it('should inject from parent view', () => {
      @Directive({selector: '[parentDir]'})
      class ParentDirective {
      }

      @Directive({selector: '[childDir]', exportAs: 'childDir'})
      class ChildDirective {
        value: string;
        constructor(public parent: ParentDirective) {
          this.value = parent.constructor.name;
        }
      }

      @Directive({selector: '[child2Dir]', exportAs: 'child2Dir'})
      class Child2Directive {
        value: boolean;
        constructor(parent: ParentDirective, child: ChildDirective) {
          this.value = parent === child.parent;
        }
      }

      @Component({
        template: `<div parentDir>
          <ng-container *ngIf="showing">
            <span childDir child2Dir #child1="childDir" #child2="child2Dir">{{ child1.value }}-{{ child2.value }}</span>
          </ng-container>
        </div>`
      })
      class MyComp {
        showing = true;
      }
      TestBed.configureTestingModule(
          {declarations: [ParentDirective, ChildDirective, Child2Directive, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      const divElement = fixture.nativeElement.querySelector('div');
      expect(divElement.textContent).toBe('ParentDirective-true');
    });
  });

  describe('Special tokens', () => {
    describe('Injector', () => {
      it('should inject the injector', () => {
        @Directive({selector: '[injectorDir]'})
        class InjectorDir {
          constructor(public injector: Injector) {}
        }

        @Directive({selector: '[otherInjectorDir]'})
        class OtherInjectorDir {
          constructor(public otherDir: InjectorDir, public injector: Injector) {}
        }

        @Component({template: '<div injectorDir otherInjectorDir></div>'})
        class MyComp {
          @ViewChild(InjectorDir) injectorDir!: InjectorDir;
          @ViewChild(OtherInjectorDir) otherInjectorDir!: OtherInjectorDir;
        }

        TestBed.configureTestingModule({declarations: [InjectorDir, OtherInjectorDir, MyComp]});
        const fixture = TestBed.createComponent(MyComp);
        fixture.detectChanges();

        const divElement = fixture.nativeElement.querySelector('div');
        const injectorDir = fixture.componentInstance.injectorDir;
        const otherInjectorDir = fixture.componentInstance.otherInjectorDir;

        expect(injectorDir.injector.get(ElementRef).nativeElement).toBe(divElement);
        expect(otherInjectorDir.injector.get(ElementRef).nativeElement).toBe(divElement);
        expect(otherInjectorDir.injector.get(InjectorDir)).toBe(injectorDir);
        expect(injectorDir.injector).not.toBe(otherInjectorDir.injector);
      });

      it('should inject INJECTOR', () => {
        @Directive({selector: '[injectorDir]'})
        class InjectorDir {
          constructor(@Inject(INJECTOR) public injector: Injector) {}
        }

        @Component({template: '<div injectorDir></div>'})
        class MyComp {
          @ViewChild(InjectorDir) injectorDir!: InjectorDir;
        }

        TestBed.configureTestingModule({declarations: [InjectorDir, MyComp]});
        const fixture = TestBed.createComponent(MyComp);
        fixture.detectChanges();

        const divElement = fixture.nativeElement.querySelector('div');
        const injectorDir = fixture.componentInstance.injectorDir;

        expect(injectorDir.injector.get(ElementRef).nativeElement).toBe(divElement);
        expect(injectorDir.injector.get(Injector).get(ElementRef).nativeElement).toBe(divElement);
        expect(injectorDir.injector.get(INJECTOR).get(ElementRef).nativeElement).toBe(divElement);
      });
    });

    describe('ElementRef', () => {
      it('should create directive with ElementRef dependencies', () => {
        @Directive({selector: '[dir]'})
        class MyDir {
          value: string;
          constructor(public elementRef: ElementRef) {
            this.value = (elementRef.constructor as any).name;
          }
        }

        @Directive({selector: '[otherDir]'})
        class MyOtherDir {
          isSameInstance: boolean;
          constructor(public elementRef: ElementRef, public directive: MyDir) {
            this.isSameInstance = elementRef === directive.elementRef;
          }
        }

        @Component({template: '<div dir otherDir></div>'})
        class MyComp {
          @ViewChild(MyDir) directive!: MyDir;
          @ViewChild(MyOtherDir) otherDirective!: MyOtherDir;
        }

        TestBed.configureTestingModule({declarations: [MyDir, MyOtherDir, MyComp]});
        const fixture = TestBed.createComponent(MyComp);
        fixture.detectChanges();

        const divElement = fixture.nativeElement.querySelector('div');
        const directive = fixture.componentInstance.directive;
        const otherDirective = fixture.componentInstance.otherDirective;

        expect(directive.value).toContain('ElementRef');
        expect(directive.elementRef.nativeElement).toEqual(divElement);
        expect(otherDirective.elementRef.nativeElement).toEqual(divElement);

        // Each ElementRef instance should be unique
        expect(otherDirective.isSameInstance).toBe(false);
      });

      it('should create ElementRef with comment if requesting directive is on <ng-template> node',
         () => {
           @Directive({selector: '[dir]'})
           class MyDir {
             value: string;
             constructor(public elementRef: ElementRef<Node>) {
               this.value = (elementRef.constructor as any).name;
             }
           }

           @Component({template: '<ng-template dir></ng-template>'})
           class MyComp {
             @ViewChild(MyDir) directive!: MyDir;
           }

           TestBed.configureTestingModule({declarations: [MyDir, MyComp]});
           const fixture = TestBed.createComponent(MyComp);
           fixture.detectChanges();

           const directive = fixture.componentInstance.directive;

           expect(directive.value).toContain('ElementRef');
           // the nativeElement should be a comment
           expect(directive.elementRef.nativeElement.nodeType).toEqual(Node.COMMENT_NODE);
         });

      it('should be available if used in conjunction with other tokens', () => {
        @Injectable()
        class ServiceA {
          subject: any;
          constructor(protected zone: NgZone) {
            this.subject = new BehaviorSubject<any>(1);
            // trigger change detection
            zone.run(() => {
              this.subject.next(2);
            });
          }
        }

        @Directive({selector: '[dir]'})
        class DirectiveA {
          constructor(public service: ServiceA, public elementRef: ElementRef) {}
        }

        @Component({
          selector: 'child',
          template: `<div id="test-id" dir></div>`,
        })
        class ChildComp {
          @ViewChild(DirectiveA) directive!: DirectiveA;
        }

        @Component({
          selector: 'root',
          template: '...',
        })
        class RootComp {
          public childCompRef!: ComponentRef<ChildComp>;

          constructor(
              public factoryResolver: ComponentFactoryResolver, public vcr: ViewContainerRef) {}

          create() {
            const factory = this.factoryResolver.resolveComponentFactory(ChildComp);
            this.childCompRef = this.vcr.createComponent(factory);
            this.childCompRef.changeDetectorRef.detectChanges();
          }
        }

        TestBed.configureTestingModule({
          declarations: [DirectiveA, RootComp, ChildComp],
          providers: [ServiceA],
        });

        const fixture = TestBed.createComponent(RootComp);
        fixture.autoDetectChanges();

        fixture.componentInstance.create();

        const {elementRef} = fixture.componentInstance.childCompRef.instance.directive;
        expect(elementRef.nativeElement.id).toBe('test-id');
      });
    });

    describe('TemplateRef', () => {
      @Directive({selector: '[dir]', exportAs: 'dir'})
      class MyDir {
        value: string;
        constructor(public templateRef: TemplateRef<any>) {
          this.value = (templateRef.constructor as any).name;
        }
      }

      it('should create directive with TemplateRef dependencies', () => {
        @Directive({selector: '[otherDir]', exportAs: 'otherDir'})
        class MyOtherDir {
          isSameInstance: boolean;
          constructor(public templateRef: TemplateRef<any>, public directive: MyDir) {
            this.isSameInstance = templateRef === directive.templateRef;
          }
        }

        @Component(
            {template: '<ng-template dir otherDir #dir="dir" #otherDir="otherDir"></ng-template>'})
        class MyComp {
          @ViewChild(MyDir) directive!: MyDir;
          @ViewChild(MyOtherDir) otherDirective!: MyOtherDir;
        }

        TestBed.configureTestingModule({declarations: [MyDir, MyOtherDir, MyComp]});
        const fixture = TestBed.createComponent(MyComp);
        fixture.detectChanges();

        const directive = fixture.componentInstance.directive;
        const otherDirective = fixture.componentInstance.otherDirective;

        expect(directive.value).toContain('TemplateRef');
        expect(directive.templateRef).not.toBeNull();
        expect(otherDirective.templateRef).not.toBeNull();

        // Each TemplateRef instance should be unique
        expect(otherDirective.isSameInstance).toBe(false);
      });

      it('should throw if injected on an element', () => {
        @Component({template: '<div dir></div>'})
        class MyComp {
        }

        TestBed.configureTestingModule({declarations: [MyDir, MyComp]});
        expect(() => TestBed.createComponent(MyComp)).toThrowError(/No provider for TemplateRef/);
      });

      it('should throw if injected on an ng-container', () => {
        @Component({template: '<ng-container dir></ng-container>'})
        class MyComp {
        }

        TestBed.configureTestingModule({declarations: [MyDir, MyComp]});
        expect(() => TestBed.createComponent(MyComp)).toThrowError(/No provider for TemplateRef/);
      });

      it('should NOT throw if optional and injected on an element', () => {
        @Directive({selector: '[optionalDir]', exportAs: 'optionalDir'})
        class OptionalDir {
          constructor(@Optional() public templateRef: TemplateRef<any>) {}
        }
        @Component({template: '<div optionalDir></div>'})
        class MyComp {
          @ViewChild(OptionalDir) directive!: OptionalDir;
        }

        TestBed.configureTestingModule({declarations: [OptionalDir, MyComp]});
        const fixture = TestBed.createComponent(MyComp);
        fixture.detectChanges();
        expect(fixture.componentInstance.directive.templateRef).toBeNull();
      });
    });

    describe('ViewContainerRef', () => {
      it('should create directive with ViewContainerRef dependencies', () => {
        @Directive({selector: '[dir]', exportAs: 'dir'})
        class MyDir {
          value: string;
          constructor(public viewContainerRef: ViewContainerRef) {
            this.value = (viewContainerRef.constructor as any).name;
          }
        }
        @Directive({selector: '[otherDir]', exportAs: 'otherDir'})
        class MyOtherDir {
          isSameInstance: boolean;
          constructor(public viewContainerRef: ViewContainerRef, public directive: MyDir) {
            this.isSameInstance = viewContainerRef === directive.viewContainerRef;
          }
        }
        @Component({template: '<div dir otherDir #dir="dir" #otherDir="otherDir"></div>'})
        class MyComp {
          @ViewChild(MyDir) directive!: MyDir;
          @ViewChild(MyOtherDir) otherDirective!: MyOtherDir;
        }

        TestBed.configureTestingModule({declarations: [MyDir, MyOtherDir, MyComp]});
        const fixture = TestBed.createComponent(MyComp);
        fixture.detectChanges();

        const directive = fixture.componentInstance.directive;
        const otherDirective = fixture.componentInstance.otherDirective;

        expect(directive.value).toContain('ViewContainerRef');
        expect(directive.viewContainerRef).not.toBeNull();
        expect(otherDirective.viewContainerRef).not.toBeNull();

        // Each ViewContainerRef instance should be unique
        expect(otherDirective.isSameInstance).toBe(false);
      });

      it('should sync ViewContainerRef state between all injected instances', () => {
        @Component({
          selector: 'root',
          template: `<ng-template #tmpl>Test</ng-template>`,
        })
        class Root {
          @ViewChild(TemplateRef, {static: true}) tmpl!: TemplateRef<any>;

          constructor(public vcr: ViewContainerRef, public vcr2: ViewContainerRef) {}

          ngOnInit(): void {
            this.vcr.createEmbeddedView(this.tmpl);
          }
        }

        TestBed.configureTestingModule({
          declarations: [Root],
        });

        const fixture = TestBed.createComponent(Root);
        fixture.detectChanges();
        const cmp = fixture.componentInstance;

        expect(cmp.vcr.length).toBe(1);
        expect(cmp.vcr2.length).toBe(1);
        expect(cmp.vcr2.get(0)).toEqual(cmp.vcr.get(0));

        cmp.vcr2.remove(0);
        expect(cmp.vcr.length).toBe(0);
        expect(cmp.vcr.get(0)).toBeNull();
      });
    });

    describe('ChangeDetectorRef', () => {
      @Directive({selector: '[dir]', exportAs: 'dir'})
      class MyDir {
        value: string;
        constructor(public cdr: ChangeDetectorRef) {
          this.value = (cdr.constructor as any).name;
        }
      }
      @Directive({selector: '[otherDir]', exportAs: 'otherDir'})
      class MyOtherDir {
        constructor(public cdr: ChangeDetectorRef) {}
      }
      @Component({selector: 'my-comp', template: '<ng-content></ng-content>'})
      class MyComp {
        constructor(public cdr: ChangeDetectorRef) {}
      }

      it('should inject host component ChangeDetectorRef into directives on templates', () => {
        let pipeInstance: MyPipe;

        @Pipe({name: 'pipe'})
        class MyPipe implements PipeTransform {
          constructor(public cdr: ChangeDetectorRef) {
            pipeInstance = this;
          }

          transform(value: any): any {
            return value;
          }
        }

        @Component({
          selector: 'my-app',
          template: `<div *ngIf="showing | pipe">Visible</div>`,
        })
        class MyApp {
          showing = true;

          constructor(public cdr: ChangeDetectorRef) {}
        }

        TestBed.configureTestingModule({declarations: [MyApp, MyPipe], imports: [CommonModule]});
        const fixture = TestBed.createComponent(MyApp);
        fixture.detectChanges();
        expect((pipeInstance!.cdr as ViewRefInternal<MyApp>).context)
            .toBe(fixture.componentInstance);
      });

      it('should inject current component ChangeDetectorRef into directives on the same node as components',
         () => {
           @Component({selector: 'my-app', template: '<my-comp dir otherDir #dir="dir"></my-comp>'})
           class MyApp {
             @ViewChild(MyComp) component!: MyComp;
             @ViewChild(MyDir) directive!: MyDir;
             @ViewChild(MyOtherDir) otherDirective!: MyOtherDir;
           }
           TestBed.configureTestingModule({declarations: [MyApp, MyComp, MyDir, MyOtherDir]});
           const fixture = TestBed.createComponent(MyApp);
           fixture.detectChanges();
           const app = fixture.componentInstance;
           const comp = fixture.componentInstance.component;
           expect((comp!.cdr as ViewRefInternal<MyComp>).context).toBe(comp);
           // ChangeDetectorRef is the token, ViewRef has historically been the constructor
           expect(app.directive.value).toContain('ViewRef');

           // Each ChangeDetectorRef instance should be unique
           expect(app.directive!.cdr).not.toBe(comp!.cdr);
           expect(app.directive!.cdr).not.toBe(app.otherDirective!.cdr);
         });

      it('should inject host component ChangeDetectorRef into directives on normal elements',
         () => {
           @Component({selector: 'my-comp', template: '<div dir otherDir #dir="dir"></div>'})
           class MyComp {
             constructor(public cdr: ChangeDetectorRef) {}
             @ViewChild(MyDir) directive!: MyDir;
             @ViewChild(MyOtherDir) otherDirective!: MyOtherDir;
           }
           TestBed.configureTestingModule({declarations: [MyComp, MyDir, MyOtherDir]});
           const fixture = TestBed.createComponent(MyComp);
           fixture.detectChanges();
           const comp = fixture.componentInstance;
           expect((comp!.cdr as ViewRefInternal<MyComp>).context).toBe(comp);
           // ChangeDetectorRef is the token, ViewRef has historically been the constructor
           expect(comp.directive.value).toContain('ViewRef');

           // Each ChangeDetectorRef instance should be unique
           expect(comp.directive!.cdr).not.toBe(comp.cdr);
           expect(comp.directive!.cdr).not.toBe(comp.otherDirective!.cdr);
         });

      it('should inject host component ChangeDetectorRef into directives in a component\'s ContentChildren',
         () => {
           @Component({
             selector: 'my-app',
             template: `<my-comp>
               <div dir otherDir #dir="dir"></div>
             </my-comp>
              `
           })
           class MyApp {
             constructor(public cdr: ChangeDetectorRef) {}
             @ViewChild(MyComp) component!: MyComp;
             @ViewChild(MyDir) directive!: MyDir;
             @ViewChild(MyOtherDir) otherDirective!: MyOtherDir;
           }
           TestBed.configureTestingModule({declarations: [MyApp, MyComp, MyDir, MyOtherDir]});
           const fixture = TestBed.createComponent(MyApp);
           fixture.detectChanges();
           const app = fixture.componentInstance;
           expect((app!.cdr as ViewRefInternal<MyApp>).context).toBe(app);
           const comp = fixture.componentInstance.component;
           // ChangeDetectorRef is the token, ViewRef has historically been the constructor
           expect(app.directive.value).toContain('ViewRef');

           // Each ChangeDetectorRef instance should be unique
           expect(app.directive!.cdr).not.toBe(comp.cdr);
           expect(app.directive!.cdr).not.toBe(app.otherDirective!.cdr);
         });

      it('should inject host component ChangeDetectorRef into directives in embedded views', () => {
        @Component({
          selector: 'my-comp',
          template: `<ng-container *ngIf="showing">
            <div dir otherDir #dir="dir" *ngIf="showing"></div>
          </ng-container>`
        })
        class MyComp {
          showing = true;
          constructor(public cdr: ChangeDetectorRef) {}
          @ViewChild(MyDir) directive!: MyDir;
          @ViewChild(MyOtherDir) otherDirective!: MyOtherDir;
        }

        TestBed.configureTestingModule({declarations: [MyComp, MyDir, MyOtherDir]});
        const fixture = TestBed.createComponent(MyComp);
        fixture.detectChanges();
        const comp = fixture.componentInstance;
        expect((comp!.cdr as ViewRefInternal<MyComp>).context).toBe(comp);
        // ChangeDetectorRef is the token, ViewRef has historically been the constructor
        expect(comp.directive.value).toContain('ViewRef');

        // Each ChangeDetectorRef instance should be unique
        expect(comp.directive!.cdr).not.toBe(comp.cdr);
        expect(comp.directive!.cdr).not.toBe(comp.otherDirective!.cdr);
      });

      it('should inject host component ChangeDetectorRef into directives on containers', () => {
        @Component(
            {selector: 'my-comp', template: '<div dir otherDir #dir="dir" *ngIf="showing"></div>'})
        class MyComp {
          showing = true;
          constructor(public cdr: ChangeDetectorRef) {}
          @ViewChild(MyDir) directive!: MyDir;
          @ViewChild(MyOtherDir) otherDirective!: MyOtherDir;
        }

        TestBed.configureTestingModule({declarations: [MyComp, MyDir, MyOtherDir]});
        const fixture = TestBed.createComponent(MyComp);
        fixture.detectChanges();
        const comp = fixture.componentInstance;
        expect((comp!.cdr as ViewRefInternal<MyComp>).context).toBe(comp);
        // ChangeDetectorRef is the token, ViewRef has historically been the constructor
        expect(comp.directive.value).toContain('ViewRef');

        // Each ChangeDetectorRef instance should be unique
        expect(comp.directive!.cdr).not.toBe(comp.cdr);
        expect(comp.directive!.cdr).not.toBe(comp.otherDirective!.cdr);
      });

      it('should inject host component ChangeDetectorRef into directives on ng-container', () => {
        let dirInstance: MyDirective;

        @Directive({selector: '[getCDR]'})
        class MyDirective {
          constructor(public cdr: ChangeDetectorRef) {
            dirInstance = this;
          }
        }

        @Component({
          selector: 'my-app',
          template: `<ng-container getCDR>Visible</ng-container>`,
        })
        class MyApp {
          constructor(public cdr: ChangeDetectorRef) {}
        }

        TestBed.configureTestingModule({declarations: [MyApp, MyDirective]});
        const fixture = TestBed.createComponent(MyApp);
        fixture.detectChanges();
        expect((dirInstance!.cdr as ViewRefInternal<MyApp>).context)
            .toBe(fixture.componentInstance);
      });
    });
  });

  describe('string tokens', () => {
    it('should be able to provide a string token', () => {
      @Directive({selector: '[injectorDir]', providers: [{provide: 'test', useValue: 'provided'}]})
      class InjectorDir {
        constructor(@Inject('test') public value: string) {}
      }

      @Component({template: '<div injectorDir></div>'})
      class MyComp {
        @ViewChild(InjectorDir) injectorDirInstance!: InjectorDir;
      }

      TestBed.configureTestingModule({declarations: [InjectorDir, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      const injectorDir = fixture.componentInstance.injectorDirInstance;

      expect(injectorDir.value).toBe('provided');
    });
  });

  describe('attribute tokens', () => {
    it('should be able to provide an attribute token', () => {
      const TOKEN = new InjectionToken<string>('Some token');
      function factory(token: string): string {
        return token + ' with factory';
      }
      @Component({
        selector: 'my-comp',
        template: '...',
        providers: [{
          provide: TOKEN,
          deps: [[new Attribute('token')]],
          useFactory: factory,
        }]
      })
      class MyComp {
        constructor(@Inject(TOKEN) readonly token: string) {}
      }

      @Component({template: `<my-comp token='token'></my-comp>`})
      class WrapperComp {
        @ViewChild(MyComp) myComp!: MyComp;
      }

      TestBed.configureTestingModule({declarations: [MyComp, WrapperComp]});

      const fixture = TestBed.createComponent(WrapperComp);
      fixture.detectChanges();
      expect(fixture.componentInstance.myComp.token).toBe('token with factory');
    });
  });

  describe('inject()', () => {
    it('should work in a directive constructor', () => {
      const TOKEN = new InjectionToken<string>('TOKEN');

      @Component({
        standalone: true,
        selector: 'test-cmp',
        template: '{{value}}',
        providers: [{provide: TOKEN, useValue: 'injected value'}],
      })
      class TestCmp {
        value: string;
        constructor() {
          this.value = inject(TOKEN);
        }
      }

      const fixture = TestBed.createComponent(TestCmp);
      fixture.detectChanges();
      expect(fixture.nativeElement.innerHTML).toEqual('injected value');
    });

    it('should work in a service constructor when the service is provided on a directive', () => {
      const TOKEN = new InjectionToken<string>('TOKEN');

      @Injectable()
      class Service {
        value: string;
        constructor() {
          this.value = inject(TOKEN);
        }
      }

      @Component({
        standalone: true,
        selector: 'test-cmp',
        template: '{{service.value}}',
        providers: [Service, {provide: TOKEN, useValue: 'injected value'}],
      })
      class TestCmp {
        constructor(readonly service: Service) {}
      }

      const fixture = TestBed.createComponent(TestCmp);
      fixture.detectChanges();
      expect(fixture.nativeElement.innerHTML).toEqual('injected value');
    });


    it('should be able to inject special tokens like ChangeDetectorRef', () => {
      const TOKEN = new InjectionToken<string>('TOKEN');

      @Component({
        standalone: true,
        selector: 'test-cmp',
        template: '{{value}}',
      })
      class TestCmp {
        cdr = inject(ChangeDetectorRef);
        value = 'before';
      }

      const fixture = TestBed.createComponent(TestCmp);
      fixture.componentInstance.value = 'after';
      fixture.componentInstance.cdr.detectChanges();
      expect(fixture.nativeElement.innerHTML).toEqual('after');
    });

    it('should work in a service constructor', () => {
      const TOKEN = new InjectionToken<string>('TOKEN', {
        providedIn: 'root',
        factory: () => 'injected value',
      });

      @Injectable({providedIn: 'root'})
      class Service {
        value: string;
        constructor() {
          this.value = inject(TOKEN);
        }
      }

      const service = TestBed.inject(Service);
      expect(service.value).toEqual('injected value');
    });

    it('should work in a useFactory definition for a service', () => {
      const TOKEN = new InjectionToken<string>('TOKEN', {
        providedIn: 'root',
        factory: () => 'injected value',
      });

      @Injectable({
        providedIn: 'root',
        useFactory: () => new Service(inject(TOKEN)),
      })
      class Service {
        constructor(readonly value: string) {}
      }

      expect(TestBed.inject(Service).value).toEqual('injected value');
    });

    it('should work for field injection', () => {
      const TOKEN = new InjectionToken<string>('TOKEN', {
        providedIn: 'root',
        factory: () => 'injected value',
      });

      @Injectable({providedIn: 'root'})
      class Service {
        value = inject(TOKEN);
      }

      const service = TestBed.inject(Service);
      expect(service.value).toEqual('injected value');
    });

    it('should not give non-node services access to the node context', () => {
      const TOKEN = new InjectionToken<string>('TOKEN');

      @Injectable({providedIn: 'root'})
      class Service {
        value: string;
        constructor() {
          this.value = inject(TOKEN, InjectFlags.Optional) ?? 'default value';
        }
      }

      @Component({
        standalone: true,
        selector: 'test-cmp',
        template: '{{service.value}}',
        providers: [{provide: TOKEN, useValue: 'injected value'}],
      })
      class TestCmp {
        service: Service;
        constructor() {
          // `Service` is injected starting from the component context, where `inject` is
          // `ɵɵdirectiveInject` under the hood. However, this should reach the root injector which
          // should _not_ use `ɵɵdirectiveInject` to inject dependencies of `Service`, so `TOKEN`
          // should not be visible to `Service`.
          this.service = inject(Service);
        }
      }

      const fixture = TestBed.createComponent(TestCmp);
      fixture.detectChanges();
      expect(fixture.nativeElement.innerHTML).toEqual('default value');
    });

    describe('with an options object argument', () => {
      it('should be able to optionally inject a service', () => {
        const TOKEN = new InjectionToken<string>('TOKEN');

        @Component({
          standalone: true,
          template: '',
        })
        class TestCmp {
          value = inject(TOKEN, {optional: true});
        }

        expect(TestBed.createComponent(TestCmp).componentInstance.value).toBeNull();
      });

      it('should be able to use skipSelf injection', () => {
        const TOKEN = new InjectionToken<string>('TOKEN', {
          providedIn: 'root',
          factory: () => 'from root',
        });
        @Component({
          standalone: true,
          template: '',
          providers: [{provide: TOKEN, useValue: 'from component'}],
        })
        class TestCmp {
          value = inject(TOKEN, {skipSelf: true});
        }

        expect(TestBed.createComponent(TestCmp).componentInstance.value).toEqual('from root');
      });

      it('should be able to use self injection', () => {
        const TOKEN = new InjectionToken<string>('TOKEN', {
          providedIn: 'root',
          factory: () => 'from root',
        });

        @Component({
          standalone: true,
          template: '',
        })
        class TestCmp {
          value = inject(TOKEN, {self: true, optional: true});
        }

        expect(TestBed.createComponent(TestCmp).componentInstance.value).toBeNull();
      });

      it('should be able to use host injection', () => {
        const TOKEN = new InjectionToken<string>('TOKEN');

        @Component({
          standalone: true,
          selector: 'child',
          template: '{{value}}',
        })
        class ChildCmp {
          value = inject(TOKEN, {host: true, optional: true}) ?? 'not found';
        }

        @Component({
          standalone: true,
          imports: [ChildCmp],
          template: '<child></child>',
          providers: [{provide: TOKEN, useValue: 'from parent'}],
          encapsulation: ViewEncapsulation.None,
        })
        class ParentCmp {
        }

        const fixture = TestBed.createComponent(ParentCmp);
        fixture.detectChanges();
        expect(fixture.nativeElement.innerHTML).toEqual('<child>not found</child>');
      });

      it('should not indicate it returns null when optional is explicitly false', () => {
        const TOKEN = new InjectionToken<string>('TOKEN', {
          providedIn: 'root',
          factory: () => 'from root',
        });

        @Component({
          standalone: true,
          template: '',
        })
        class TestCmp {
          // TypeScript will check if this assignment is legal, which won't be the case if
          // inject() erroneously returns a `string|null` type here.
          value: string = inject(TOKEN, {optional: false});
        }

        expect(TestBed.createComponent(TestCmp).componentInstance.value).toEqual('from root');
      });
    });
  });

  describe('injection flags', () => {
    describe('represented as an options object argument', () => {
      it('should be able to optionally inject a service', () => {
        const TOKEN = new InjectionToken<string>('TOKEN');

        @Component({
          standalone: true,
          template: '',
        })
        class TestCmp {
          nodeInjector = inject(Injector);
          envInjector = inject(EnvironmentInjector);
        }

        const {nodeInjector, envInjector} = TestBed.createComponent(TestCmp).componentInstance;

        expect(nodeInjector.get(TOKEN, undefined, {optional: true})).toBeNull();
        expect(nodeInjector.get(TOKEN, undefined, InjectFlags.Optional)).toBeNull();

        expect(envInjector.get(TOKEN, undefined, {optional: true})).toBeNull();
        expect(envInjector.get(TOKEN, undefined, InjectFlags.Optional)).toBeNull();
      });

      it('should be able to use skipSelf injection in NodeInjector', () => {
        const TOKEN = new InjectionToken<string>('TOKEN', {
          providedIn: 'root',
          factory: () => 'from root',
        });
        @Component({
          standalone: true,
          template: '',
          providers: [{provide: TOKEN, useValue: 'from component'}],
        })
        class TestCmp {
          nodeInjector = inject(Injector);
        }

        const {nodeInjector} = TestBed.createComponent(TestCmp).componentInstance;
        expect(nodeInjector.get(TOKEN, undefined, {skipSelf: true})).toEqual('from root');
      });

      it('should be able to use skipSelf injection in EnvironmentInjector', () => {
        const TOKEN = new InjectionToken<string>('TOKEN');
        const parent = TestBed.inject(EnvironmentInjector);
        const root = createEnvironmentInjector([{provide: TOKEN, useValue: 'from root'}], parent);
        const child = createEnvironmentInjector([{provide: TOKEN, useValue: 'from child'}], root);

        expect(child.get(TOKEN)).toEqual('from child');
        expect(child.get(TOKEN, undefined, {skipSelf: true})).toEqual('from root');
        expect(child.get(TOKEN, undefined, InjectFlags.SkipSelf)).toEqual('from root');
      });

      it('should be able to use self injection in NodeInjector', () => {
        const TOKEN = new InjectionToken<string>('TOKEN', {
          providedIn: 'root',
          factory: () => 'from root',
        });

        @Component({
          standalone: true,
          template: '',
        })
        class TestCmp {
          nodeInjector = inject(Injector);
        }

        const {nodeInjector} = TestBed.createComponent(TestCmp).componentInstance;
        expect(nodeInjector.get(TOKEN, undefined, {self: true, optional: true})).toBeNull();
      });

      it('should be able to use self injection in EnvironmentInjector', () => {
        const TOKEN = new InjectionToken<string>('TOKEN');
        const parent = TestBed.inject(EnvironmentInjector);
        const root = createEnvironmentInjector([{provide: TOKEN, useValue: 'from root'}], parent);
        const child = createEnvironmentInjector([], root);

        expect(child.get(TOKEN, undefined, {self: true, optional: true})).toBeNull();
        expect(child.get(TOKEN, undefined, InjectFlags.Self | InjectFlags.Optional)).toBeNull();
      });

      it('should be able to use host injection', () => {
        const TOKEN = new InjectionToken<string>('TOKEN');

        @Component({
          standalone: true,
          selector: 'child',
          template: '{{ a }}|{{ b }}',
        })
        class ChildCmp {
          nodeInjector = inject(Injector);
          a = this.nodeInjector.get(TOKEN, 'not found', {host: true, optional: true});
          b = this.nodeInjector.get(TOKEN, 'not found', InjectFlags.Host|InjectFlags.Optional);
        }

        @Component({
          standalone: true,
          imports: [ChildCmp],
          template: '<child></child>',
          providers: [{provide: TOKEN, useValue: 'from parent'}],
          encapsulation: ViewEncapsulation.None,
        })
        class ParentCmp {
        }

        const fixture = TestBed.createComponent(ParentCmp);
        fixture.detectChanges();
        expect(fixture.nativeElement.innerHTML).toEqual('<child>not found|not found</child>');
      });
    });
  });

  it('should be able to use Host in `useFactory` dependency config', () => {
    // Scenario:
    // ---------
    // <root (provides token A)>
    //   <comp (provides token B via useFactory(@Host() @Inject(A))></comp>
    // </root>
    @Component({
      selector: 'root',
      template: '<comp></comp>',
      viewProviders: [{
        provide: 'A',
        useValue: 'A from Root',
      }]
    })
    class Root {
    }

    @Component({
      selector: 'comp',
      template: '{{ token }}',
      viewProviders: [{
        provide: 'B',
        deps: [[new Inject('A'), new Host()]],
        useFactory: (token: string) => `${token} (processed by useFactory)`,
      }]
    })
    class Comp {
      constructor(@Inject('B') readonly token: string) {}
    }

    @Component({
      template: `<root></root>`,
    })
    class App {
    }

    TestBed.configureTestingModule({declarations: [Root, Comp, App]});

    const fixture = TestBed.createComponent(App);
    fixture.detectChanges();

    expect(fixture.nativeElement.textContent).toBe('A from Root (processed by useFactory)');
  });

  it('should not lookup outside of the host element when Host is used in `useFactory`', () => {
    // Scenario:
    // ---------
    // <root (provides token A)>
    //   <intermediate>
    //     <comp (provides token B via useFactory(@Host() @Inject(A))></comp>
    //   </intermediate>
    // </root>
    @Component({
      selector: 'root',
      template: '<intermediate></intermediate>',
      viewProviders: [{
        provide: 'A',
        useValue: 'A from Root',
      }]
    })
    class Root {
    }

    @Component({
      selector: 'intermediate',
      template: '<comp></comp>',
    })
    class Intermediate {
    }

    @Component({
      selector: 'comp',
      template: '{{ token }}',
      viewProviders: [{
        provide: 'B',
        deps: [[new Inject('A'), new Host(), new Optional()]],
        useFactory: (token: string) =>
            token ? `${token} (processed by useFactory)` : 'No token A found',
      }]
    })
    class Comp {
      constructor(@Inject('B') readonly token: string) {}
    }

    @Component({
      template: `<root></root>`,
    })
    class App {
    }

    TestBed.configureTestingModule({declarations: [Root, Comp, App, Intermediate]});

    const fixture = TestBed.createComponent(App);
    fixture.detectChanges();

    // Making sure that the `@Host` takes effect and token `A` becomes unavailable in DI since it's
    // defined one level up from the Comp's host view.
    expect(fixture.nativeElement.textContent).toBe('No token A found');
  });

  it('should not cause cyclic dependency if same token is requested in deps with @SkipSelf', () => {
    @Component({
      selector: 'my-comp',
      template: '...',
      providers: [{
        provide: LOCALE_ID,
        useFactory: () => 'ja-JP',
        // Note: `LOCALE_ID` is also provided within APPLICATION_MODULE_PROVIDERS, so we use it
        // here as a dep and making sure it doesn't cause cyclic dependency (since @SkipSelf is
        // present)
        deps: [[new Inject(LOCALE_ID), new Optional(), new SkipSelf()]]
      }]
    })
    class MyComp {
      constructor(@Inject(LOCALE_ID) public localeId: string) {}
    }

    TestBed.configureTestingModule({declarations: [MyComp]});
    const fixture = TestBed.createComponent(MyComp);
    fixture.detectChanges();
    expect(fixture.componentInstance.localeId).toBe('ja-JP');
  });

  it('module-level deps should not access Component/Directive providers', () => {
    @Component({
      selector: 'my-comp',
      template: '...',
      providers: [{
        provide: 'LOCALE_ID_DEP',  //
        useValue: 'LOCALE_ID_DEP_VALUE'
      }]
    })
    class MyComp {
      constructor(@Inject(LOCALE_ID) public localeId: string) {}
    }

    TestBed.configureTestingModule({
      declarations: [MyComp],
      providers: [{
        provide: LOCALE_ID,
        // we expect `localeDepValue` to be undefined, since it's not provided at a module level
        useFactory: (localeDepValue: any) => localeDepValue || 'en-GB',
        deps: [[new Inject('LOCALE_ID_DEP'), new Optional()]]
      }]
    });
    const fixture = TestBed.createComponent(MyComp);
    fixture.detectChanges();
    expect(fixture.componentInstance.localeId).toBe('en-GB');
  });

  it('should skip current level while retrieving tokens if @SkipSelf is defined', () => {
    @Component({
      selector: 'my-comp',
      template: '...',
      providers: [{provide: LOCALE_ID, useFactory: () => 'en-GB'}]
    })
    class MyComp {
      constructor(@SkipSelf() @Inject(LOCALE_ID) public localeId: string) {}
    }

    TestBed.configureTestingModule({declarations: [MyComp]});
    const fixture = TestBed.createComponent(MyComp);
    fixture.detectChanges();
    // takes `LOCALE_ID` from module injector, since we skip Component level with @SkipSelf
    expect(fixture.componentInstance.localeId).toBe(DEFAULT_LOCALE_ID);
  });

  it('should work when injecting dependency in Directives', () => {
    @Directive({
      selector: '[dir]',  //
      providers: [{provide: LOCALE_ID, useValue: 'ja-JP'}]
    })
    class MyDir {
      constructor(@SkipSelf() @Inject(LOCALE_ID) public localeId: string) {}
    }
    @Component({
      selector: 'my-comp',
      template: '<div dir></div>',
      providers: [{provide: LOCALE_ID, useValue: 'en-GB'}]
    })
    class MyComp {
      @ViewChild(MyDir) myDir!: MyDir;
      constructor(@Inject(LOCALE_ID) public localeId: string) {}
    }

    TestBed.configureTestingModule({declarations: [MyDir, MyComp, MyComp]});
    const fixture = TestBed.createComponent(MyComp);
    fixture.detectChanges();
    expect(fixture.componentInstance.myDir.localeId).toBe('en-GB');
  });

  describe('@Attribute', () => {
    it('should inject attributes', () => {
      @Directive({selector: '[dir]'})
      class MyDir {
        constructor(
            @Attribute('exist') public exist: string,
            @Attribute('nonExist') public nonExist: string) {}
      }

      @Component({template: '<div dir exist="existValue" other="ignore"></div>'})
      class MyComp {
        @ViewChild(MyDir) directiveInstance!: MyDir;
      }

      TestBed.configureTestingModule({declarations: [MyDir, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      const directive = fixture.componentInstance.directiveInstance;

      expect(directive.exist).toBe('existValue');
      expect(directive.nonExist).toBeNull();
    });

    it('should inject attributes on <ng-template>', () => {
      @Directive({selector: '[dir]'})
      class MyDir {
        constructor(
            @Attribute('exist') public exist: string,
            @Attribute('dir') public myDirectiveAttrValue: string) {}
      }

      @Component(
          {template: '<ng-template dir="initial" exist="existValue" other="ignore"></ng-template>'})
      class MyComp {
        @ViewChild(MyDir) directiveInstance!: MyDir;
      }

      TestBed.configureTestingModule({declarations: [MyDir, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      const directive = fixture.componentInstance.directiveInstance;

      expect(directive.exist).toBe('existValue');
      expect(directive.myDirectiveAttrValue).toBe('initial');
    });

    it('should inject attributes on <ng-container>', () => {
      @Directive({selector: '[dir]'})
      class MyDir {
        constructor(
            @Attribute('exist') public exist: string,
            @Attribute('dir') public myDirectiveAttrValue: string) {}
      }

      @Component({
        template: '<ng-container dir="initial" exist="existValue" other="ignore"></ng-container>'
      })
      class MyComp {
        @ViewChild(MyDir) directiveInstance!: MyDir;
      }

      TestBed.configureTestingModule({declarations: [MyDir, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      const directive = fixture.componentInstance.directiveInstance;

      expect(directive.exist).toBe('existValue');
      expect(directive.myDirectiveAttrValue).toBe('initial');
    });

    it('should be able to inject different kinds of attributes', () => {
      @Directive({selector: '[dir]'})
      class MyDir {
        constructor(
            @Attribute('class') public className: string,
            @Attribute('style') public inlineStyles: string,
            @Attribute('other-attr') public otherAttr: string) {}
      }

      @Component({
        template:
            '<div dir style="margin: 1px; color: red;" class="hello there" other-attr="value"></div>'
      })
      class MyComp {
        @ViewChild(MyDir) directiveInstance!: MyDir;
      }

      TestBed.configureTestingModule({declarations: [MyDir, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      const directive = fixture.componentInstance.directiveInstance;

      expect(directive.otherAttr).toBe('value');
      expect(directive.className).toBe('hello there');
      expect(directive.inlineStyles).toMatch(/color:\s*red/);
      expect(directive.inlineStyles).toMatch(/margin:\s*1px/);
    });

    it('should not inject attributes with namespace', () => {
      @Directive({selector: '[dir]'})
      class MyDir {
        constructor(
            @Attribute('exist') public exist: string,
            @Attribute('svg:exist') public namespacedExist: string,
            @Attribute('other') public other: string) {}
      }

      @Component({
        template: '<div dir exist="existValue" svg:exist="testExistValue" other="otherValue"></div>'
      })
      class MyComp {
        @ViewChild(MyDir) directiveInstance!: MyDir;
      }

      TestBed.configureTestingModule({declarations: [MyDir, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      const directive = fixture.componentInstance.directiveInstance;

      expect(directive.exist).toBe('existValue');
      expect(directive.namespacedExist).toBeNull();
      expect(directive.other).toBe('otherValue');
    });

    it('should not inject attributes representing bindings and outputs', () => {
      @Directive({selector: '[dir]'})
      class MyDir {
        @Input() binding!: string;
        @Output() output = new EventEmitter();
        constructor(
            @Attribute('exist') public exist: string,
            @Attribute('binding') public bindingAttr: string,
            @Attribute('output') public outputAttr: string,
            @Attribute('other') public other: string) {}
      }

      @Component({
        template:
            '<div dir exist="existValue" [binding]="bindingValue" (output)="outputValue" other="otherValue" ignore="ignoreValue"></div>'
      })
      class MyComp {
        @ViewChild(MyDir) directiveInstance!: MyDir;
      }

      TestBed.configureTestingModule({declarations: [MyDir, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      const directive = fixture.componentInstance.directiveInstance;

      expect(directive.exist).toBe('existValue');
      expect(directive.bindingAttr).toBeNull();
      expect(directive.outputAttr).toBeNull();
      expect(directive.other).toBe('otherValue');
    });

    it('should inject `null` for attributes with data bindings', () => {
      @Directive({selector: '[dir]'})
      class MyDir {
        constructor(@Attribute('title') public attrValue: string) {}
      }

      @Component({template: '<div dir title="title {{ value }}"></div>'})
      class MyComp {
        @ViewChild(MyDir) directiveInstance!: MyDir;
        value = 'value';
      }

      TestBed.configureTestingModule({declarations: [MyDir, MyComp]});
      const fixture = TestBed.createComponent(MyComp);
      fixture.detectChanges();

      expect(fixture.componentInstance.directiveInstance.attrValue).toBeNull();
      expect(fixture.nativeElement.querySelector('div').getAttribute('title')).toBe('title value');
    });
  });

  it('should support dependencies in Pipes used inside ICUs', () => {
    @Injectable()
    class MyService {
      transform(value: string): string {
        return `${value} (transformed)`;
      }
    }

    @Pipe({name: 'somePipe'})
    class MyPipe {
      constructor(private service: MyService) {}
      transform(value: any): any {
        return this.service.transform(value);
      }
    }

    @Component({
      template: `
        <div i18n>{
          count, select,
          =1 {One}
          other {Other value is: {{count | somePipe}}}
        }</div>
      `
    })
    class MyComp {
      count = '2';
    }

    TestBed.configureTestingModule({
      declarations: [MyPipe, MyComp],
      providers: [MyService],
    });
    const fixture = TestBed.createComponent(MyComp);
    fixture.detectChanges();

    expect(fixture.nativeElement.innerHTML).toContain('Other value is: 2 (transformed)');
  });

  it('should support dependencies in Pipes used inside i18n blocks', () => {
    @Injectable()
    class MyService {
      transform(value: string): string {
        return `${value} (transformed)`;
      }
    }

    @Pipe({name: 'somePipe'})
    class MyPipe {
      constructor(private service: MyService) {}
      transform(value: any): any {
        return this.service.transform(value);
      }
    }

    @Component({
      template: `
        <ng-template #source i18n>
          {{count | somePipe}} <span>items</span>
        </ng-template>
        <ng-container #target></ng-container>
      `
    })
    class MyComp {
      count = '2';

      @ViewChild('target', {read: ViewContainerRef}) target!: ViewContainerRef;
      @ViewChild('source', {read: TemplateRef}) source!: TemplateRef<any>;

      create() {
        this.target.createEmbeddedView(this.source);
      }
    }

    TestBed.configureTestingModule({
      declarations: [MyPipe, MyComp],
      providers: [MyService],
    });
    const fixture = TestBed.createComponent(MyComp);
    fixture.detectChanges();

    fixture.componentInstance.create();
    fixture.detectChanges();

    expect(fixture.nativeElement.textContent.trim()).toBe('2 (transformed) items');
  });

  // TODO: https://angular-team.atlassian.net/browse/FW-1779
  it('should prioritize useFactory over useExisting', () => {
    abstract class Base {}
    @Directive({selector: '[dirA]'})
    class DirA implements Base {
    }
    @Directive({selector: '[dirB]'})
    class DirB implements Base {
    }

    const PROVIDER = {provide: Base, useExisting: DirA, useFactory: () => new DirB()};

    @Component({selector: 'child', template: '', providers: [PROVIDER]})
    class Child {
      constructor(readonly base: Base) {}
    }

    @Component({template: `<div dirA> <child></child> </div>`})
    class App {
      @ViewChild(DirA) dirA!: DirA;
      @ViewChild(Child) child!: Child;
    }

    const fixture = TestBed.configureTestingModule({declarations: [DirA, DirB, App, Child]})
                        .createComponent(App);
    fixture.detectChanges();
    expect(fixture.componentInstance.dirA)
        .not.toEqual(
            fixture.componentInstance.child.base,
            'should not get dirA from parent, but create new dirB from the useFactory provider');
  });


  describe('provider access on the same node', () => {
    const token = new InjectionToken<number>('token');

    it('pipes should access providers from the component they are on', () => {
      @Pipe({name: 'token'})
      class TokenPipe {
        constructor(@Inject(token) private _token: string) {}

        transform(value: string): string {
          return value + this._token;
        }
      }

      @Component({
        selector: 'child-comp',
        template: '{{value}}',
        providers: [{provide: token, useValue: 'child'}]
      })
      class ChildComp {
        @Input() value: any;
      }

      @Component({
        template: `<child-comp [value]="'' | token"></child-comp>`,
        providers: [{provide: token, useValue: 'parent'}]
      })
      class App {
      }

      TestBed.configureTestingModule({declarations: [App, ChildComp, TokenPipe]});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      expect(fixture.nativeElement.textContent.trim()).toBe('child');
    });

    it('pipes should not access viewProviders from the component they are on', () => {
      @Pipe({name: 'token'})
      class TokenPipe {
        constructor(@Inject(token) private _token: string) {}

        transform(value: string): string {
          return value + this._token;
        }
      }

      @Component({
        selector: 'child-comp',
        template: '{{value}}',
        viewProviders: [{provide: token, useValue: 'child'}]
      })
      class ChildComp {
        @Input() value: any;
      }

      @Component({
        template: `<child-comp [value]="'' | token"></child-comp>`,
        viewProviders: [{provide: token, useValue: 'parent'}]
      })
      class App {
      }

      TestBed.configureTestingModule({declarations: [App, ChildComp, TokenPipe]});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      expect(fixture.nativeElement.textContent.trim()).toBe('parent');
    });

    it('directives should access providers from the component they are on', () => {
      @Directive({selector: '[dir]'})
      class Dir {
        constructor(@Inject(token) public token: string) {}
      }

      @Component({
        selector: 'child-comp',
        template: '',
        providers: [{provide: token, useValue: 'child'}],
      })
      class ChildComp {
      }

      @Component({
        template: '<child-comp dir></child-comp>',
        providers: [{provide: token, useValue: 'parent'}]
      })
      class App {
        @ViewChild(Dir) dir!: Dir;
      }

      TestBed.configureTestingModule({declarations: [App, ChildComp, Dir]});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      expect(fixture.componentInstance.dir.token).toBe('child');
    });

    it('directives should not access viewProviders from the component they are on', () => {
      @Directive({selector: '[dir]'})
      class Dir {
        constructor(@Inject(token) public token: string) {}
      }

      @Component({
        selector: 'child-comp',
        template: '',
        viewProviders: [{provide: token, useValue: 'child'}]
      })
      class ChildComp {
      }

      @Component({
        template: '<child-comp dir></child-comp>',
        viewProviders: [{provide: token, useValue: 'parent'}]
      })
      class App {
        @ViewChild(Dir) dir!: Dir;
      }

      TestBed.configureTestingModule({declarations: [App, ChildComp, Dir]});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      expect(fixture.componentInstance.dir.token).toBe('parent');
    });
  });

  it('should not be able to inject ViewRef', () => {
    @Component({template: ''})
    class App {
      constructor(_viewRef: ViewRef) {}
    }

    TestBed.configureTestingModule({declarations: [App]});
    expect(() => TestBed.createComponent(App)).toThrowError(/NullInjectorError/);
  });

  describe('injector when creating embedded view', () => {
    const token = new InjectionToken<string>('greeting');

    @Directive({selector: 'menu-trigger'})
    class MenuTrigger {
      @Input('triggerFor') menu!: TemplateRef<unknown>;

      constructor(private viewContainerRef: ViewContainerRef) {}

      open(injector: Injector|undefined) {
        this.viewContainerRef.createEmbeddedView(this.menu, undefined, {injector});
      }
    }

    it('should be able to provide an injection token through a custom injector', () => {
      @Directive({selector: 'menu'})
      class Menu {
        constructor(@Inject(token) public tokenValue: string) {}
      }

      @Component({
        template: `
          <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
          <ng-template #menuTemplate>
            <menu></menu>
          </ng-template>
      `
      })
      class App {
        @ViewChild(MenuTrigger) trigger!: MenuTrigger;
        @ViewChild(Menu) menu!: Menu;
      }

      TestBed.configureTestingModule({declarations: [App, MenuTrigger, Menu]});
      const injector = Injector.create({providers: [{provide: token, useValue: 'hello'}]});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      fixture.componentInstance.trigger.open(injector);
      fixture.detectChanges();

      expect(fixture.componentInstance.menu.tokenValue).toBe('hello');
    });

    it('should be able to provide an injection token to a nested template through a custom injector',
       () => {
         @Directive({selector: 'menu'})
         class Menu {
           constructor(@Inject(token) public tokenValue: string) {}
         }

         @Component({
           template: `
            <menu-trigger #outerTrigger [triggerFor]="outerTemplate"></menu-trigger>
            <ng-template #outerTemplate>
              <menu></menu>

              <menu-trigger #innerTrigger [triggerFor]="innerTemplate"></menu-trigger>
              <ng-template #innerTemplate>
                <menu #innerMenu></menu>
              </ng-template>
            </ng-template>
          `
         })
         class App {
           @ViewChild('outerTrigger', {read: MenuTrigger}) outerTrigger!: MenuTrigger;
           @ViewChild('innerTrigger', {read: MenuTrigger}) innerTrigger!: MenuTrigger;
           @ViewChild('innerMenu', {read: Menu}) innerMenu!: Menu;
         }

         TestBed.configureTestingModule({declarations: [App, MenuTrigger, Menu]});
         const fixture = TestBed.createComponent(App);
         fixture.detectChanges();

         fixture.componentInstance.outerTrigger.open(
             Injector.create({providers: [{provide: token, useValue: 'hello'}]}));
         fixture.detectChanges();

         fixture.componentInstance.innerTrigger.open(undefined);
         fixture.detectChanges();

         expect(fixture.componentInstance.innerMenu.tokenValue).toBe('hello');
       });

    it('should be able to resolve a token from a custom grandparent injector if the token is not provided in the parent',
       () => {
         @Directive({selector: 'menu'})
         class Menu {
           constructor(@Inject(token) public tokenValue: string) {}
         }

         @Component({
           template: `
            <menu-trigger #grandparentTrigger [triggerFor]="grandparentTemplate"></menu-trigger>
            <ng-template #grandparentTemplate>
              <menu></menu>

              <menu-trigger #parentTrigger [triggerFor]="parentTemplate"></menu-trigger>
              <ng-template #parentTemplate>
                <menu></menu>

                <menu-trigger #childTrigger [triggerFor]="childTemplate"></menu-trigger>
                <ng-template #childTemplate>
                  <menu #childMenu></menu>
                </ng-template>
              </ng-template>
            </ng-template>
          `
         })
         class App {
           @ViewChild('grandparentTrigger', {read: MenuTrigger}) grandparentTrigger!: MenuTrigger;
           @ViewChild('parentTrigger', {read: MenuTrigger}) parentTrigger!: MenuTrigger;
           @ViewChild('childTrigger', {read: MenuTrigger}) childTrigger!: MenuTrigger;
           @ViewChild('childMenu', {read: Menu}) childMenu!: Menu;
         }

         TestBed.configureTestingModule({declarations: [App, MenuTrigger, Menu]});
         const fixture = TestBed.createComponent(App);
         fixture.detectChanges();

         fixture.componentInstance.grandparentTrigger.open(
             Injector.create({providers: [{provide: token, useValue: 'hello'}]}));
         fixture.detectChanges();

         fixture.componentInstance.parentTrigger.open(Injector.create({providers: []}));
         fixture.detectChanges();

         fixture.componentInstance.childTrigger.open(undefined);
         fixture.detectChanges();

         expect(fixture.componentInstance.childMenu.tokenValue).toBe('hello');
       });

    it('should resolve value from node injector if it is lower than embedded view injector', () => {
      @Directive({selector: 'menu'})
      class Menu {
        constructor(@Inject(token) public tokenValue: string) {}
      }

      @Component({
        selector: 'wrapper',
        providers: [{provide: token, useValue: 'hello from wrapper'}],
        template: `
          <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
          <ng-template #menuTemplate>
            <menu></menu>
          </ng-template>
        `
      })
      class Wrapper {
        @ViewChild(MenuTrigger) trigger!: MenuTrigger;
        @ViewChild(Menu) menu!: Menu;
      }

      @Component({
        template: `
          <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
          <ng-template #menuTemplate>
            <wrapper></wrapper>
          </ng-template>
        `
      })
      class App {
        @ViewChild(MenuTrigger) trigger!: MenuTrigger;
        @ViewChild(Wrapper) wrapper!: Wrapper;
      }

      TestBed.configureTestingModule({declarations: [App, MenuTrigger, Menu, Wrapper]});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      fixture.componentInstance.trigger.open(
          Injector.create({providers: [{provide: token, useValue: 'hello from injector'}]}));
      fixture.detectChanges();

      fixture.componentInstance.wrapper.trigger.open(undefined);
      fixture.detectChanges();

      expect(fixture.componentInstance.wrapper.menu.tokenValue).toBe('hello from wrapper');
    });

    it('should be able to inject a value provided at the module level', () => {
      @Directive({selector: 'menu'})
      class Menu {
        constructor(@Inject(token) public tokenValue: string) {}
      }

      @Component({
        template: `
          <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
          <ng-template #menuTemplate>
            <menu></menu>
          </ng-template>
      `
      })
      class App {
        @ViewChild(MenuTrigger) trigger!: MenuTrigger;
        @ViewChild(Menu) menu!: Menu;
      }

      @NgModule({
        declarations: [App, MenuTrigger, Menu],
        exports: [App, MenuTrigger, Menu],
        providers: [{provide: token, useValue: 'hello'}]
      })
      class Module {
      }

      TestBed.configureTestingModule({imports: [Module]});
      const injector = Injector.create({providers: []});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      fixture.componentInstance.trigger.open(injector);
      fixture.detectChanges();

      expect(fixture.componentInstance.menu.tokenValue).toBe('hello');
    });

    it('should have value from custom injector take precedence over module injector', () => {
      @Directive({selector: 'menu'})
      class Menu {
        constructor(@Inject(token) public tokenValue: string) {}
      }

      @Component({
        template: `
          <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
          <ng-template #menuTemplate>
            <menu></menu>
          </ng-template>
      `
      })
      class App {
        @ViewChild(MenuTrigger) trigger!: MenuTrigger;
        @ViewChild(Menu) menu!: Menu;
      }

      @NgModule({
        declarations: [App, MenuTrigger, Menu],
        exports: [App, MenuTrigger, Menu],
        providers: [{provide: token, useValue: 'hello from module'}]
      })
      class Module {
      }

      TestBed.configureTestingModule({imports: [Module]});
      const injector =
          Injector.create({providers: [{provide: token, useValue: 'hello from injector'}]});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      fixture.componentInstance.trigger.open(injector);
      fixture.detectChanges();

      expect(fixture.componentInstance.menu.tokenValue).toBe('hello from injector');
    });

    it('should have value from custom injector take precedence over parent injector', () => {
      @Directive({selector: 'menu'})
      class Menu {
        constructor(@Inject(token) public tokenValue: string) {}
      }

      @Component({
        template: `
          <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
          <ng-template #menuTemplate>
            <menu></menu>
          </ng-template>
      `,
        providers: [{provide: token, useValue: 'hello from parent'}]
      })
      class App {
        @ViewChild(MenuTrigger) trigger!: MenuTrigger;
        @ViewChild(Menu) menu!: Menu;
      }

      @NgModule({
        declarations: [App, MenuTrigger, Menu],
        exports: [App, MenuTrigger, Menu],
      })
      class Module {
      }

      TestBed.configureTestingModule({imports: [Module]});
      const injector =
          Injector.create({providers: [{provide: token, useValue: 'hello from injector'}]});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      fixture.componentInstance.trigger.open(injector);
      fixture.detectChanges();

      expect(fixture.componentInstance.menu.tokenValue).toBe('hello from injector');
    });

    it('should be able to inject built-in tokens when a custom injector is provided', () => {
      @Directive({selector: 'menu'})
      class Menu {
        constructor(public elementRef: ElementRef, public changeDetectorRef: ChangeDetectorRef) {}
      }

      @Component({
        template: `
          <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
          <ng-template #menuTemplate>
            <menu></menu>
          </ng-template>
      `
      })
      class App {
        @ViewChild(MenuTrigger) trigger!: MenuTrigger;
        @ViewChild(Menu) menu!: Menu;
      }

      TestBed.configureTestingModule({declarations: [App, MenuTrigger, Menu]});
      const injector = Injector.create({providers: []});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      fixture.componentInstance.trigger.open(injector);
      fixture.detectChanges();

      expect(fixture.componentInstance.menu.elementRef.nativeElement)
          .toBe(fixture.nativeElement.querySelector('menu'));
      expect(fixture.componentInstance.menu.changeDetectorRef).toBeTruthy();
    });

    it('should have value from parent component injector take precedence over module injector',
       () => {
         @Directive({selector: 'menu'})
         class Menu {
           constructor(@Inject(token) public tokenValue: string) {}
         }

         @Component({
           template: `
            <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
            <ng-template #menuTemplate>
              <menu></menu>
            </ng-template>
          `,
           providers: [{provide: token, useValue: 'hello from parent'}]
         })
         class App {
           @ViewChild(MenuTrigger) trigger!: MenuTrigger;
           @ViewChild(Menu) menu!: Menu;
         }

         @NgModule({
           declarations: [App, MenuTrigger, Menu],
           exports: [App, MenuTrigger, Menu],
           providers: [{provide: token, useValue: 'hello from module'}]
         })
         class Module {
         }

         TestBed.configureTestingModule({imports: [Module]});
         const injector = Injector.create({providers: []});
         const fixture = TestBed.createComponent(App);
         fixture.detectChanges();

         fixture.componentInstance.trigger.open(injector);
         fixture.detectChanges();

         expect(fixture.componentInstance.menu.tokenValue).toBe('hello from parent');
       });

    it('should be able to inject an injectable with dependencies', () => {
      @Injectable()
      class Greeter {
        constructor(@Inject(token) private tokenValue: string) {}

        greet() {
          return `hello from ${this.tokenValue}`;
        }
      }

      @Directive({selector: 'menu'})
      class Menu {
        constructor(public greeter: Greeter) {}
      }

      @Component({
        template: `
          <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
          <ng-template #menuTemplate>
            <menu></menu>
          </ng-template>
      `
      })
      class App {
        @ViewChild(MenuTrigger) trigger!: MenuTrigger;
        @ViewChild(Menu) menu!: Menu;
      }

      @NgModule({
        declarations: [App, MenuTrigger, Menu],
        exports: [App, MenuTrigger, Menu],
        providers: [{provide: token, useValue: 'module'}]
      })
      class Module {
      }

      TestBed.configureTestingModule({imports: [Module]});
      const injector = Injector.create({
        providers: [
          {provide: Greeter, useClass: Greeter},
          {provide: token, useValue: 'injector'},
        ]
      });
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      fixture.componentInstance.trigger.open(injector);
      fixture.detectChanges();

      expect(fixture.componentInstance.menu.greeter.greet()).toBe('hello from injector');
    });

    it('should be able to inject a value from a grandparent component when a custom injector is provided',
       () => {
         @Directive({selector: 'menu'})
         class Menu {
           constructor(@Inject(token) public tokenValue: string) {}
         }

         @Component({
           selector: 'parent',
           template: `
            <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
            <ng-template #menuTemplate>
              <menu></menu>
            </ng-template>
           `
         })
         class Parent {
           @ViewChild(MenuTrigger) trigger!: MenuTrigger;
           @ViewChild(Menu) menu!: Menu;
         }

         @Component({
           template: '<parent></parent>',
           providers: [{provide: token, useValue: 'hello from grandparent'}]
         })
         class GrandParent {
           @ViewChild(Parent) parent!: Parent;
         }

         TestBed.configureTestingModule({declarations: [GrandParent, Parent, MenuTrigger, Menu]});
         const injector = Injector.create({providers: []});
         const fixture = TestBed.createComponent(GrandParent);
         fixture.detectChanges();

         fixture.componentInstance.parent.trigger.open(injector);
         fixture.detectChanges();

         expect(fixture.componentInstance.parent.menu.tokenValue).toBe('hello from grandparent');
       });

    it('should be able to use a custom injector when created through TemplateRef', () => {
      let injectedValue: string|undefined;

      @Directive({selector: 'menu'})
      class Menu {
        constructor(@Inject(token) tokenValue: string) {
          injectedValue = tokenValue;
        }
      }

      @Component({
        template: `
          <ng-template>
            <menu></menu>
          </ng-template>
        `
      })
      class App {
        @ViewChild(TemplateRef) template!: TemplateRef<unknown>;
      }

      @NgModule({
        declarations: [App, Menu],
        exports: [App, Menu],
        providers: [{provide: token, useValue: 'hello from module'}]
      })
      class Module {
      }

      TestBed.configureTestingModule({imports: [Module]});
      const injector =
          Injector.create({providers: [{provide: token, useValue: 'hello from injector'}]});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      fixture.componentInstance.template.createEmbeddedView({}, injector);
      fixture.detectChanges();

      expect(injectedValue).toBe('hello from injector');
    });

    it('should use a custom injector when the view is created outside of the declaration view',
       () => {
         const declarerToken = new InjectionToken<string>('declarerToken');
         const creatorToken = new InjectionToken<string>('creatorToken');

         @Directive({selector: 'menu'})
         class Menu {
           constructor(
               @Inject(token) public tokenValue: string,
               @Optional() @Inject(declarerToken) public declarerTokenValue: string,
               @Optional() @Inject(creatorToken) public creatorTokenValue: string) {}
         }

         @Component({
           selector: 'declarer',
           template: '<ng-template><menu></menu></ng-template>',
           providers: [{provide: declarerToken, useValue: 'hello from declarer'}]
         })
         class Declarer {
           @ViewChild(Menu) menu!: Menu;
           @ViewChild(TemplateRef) template!: TemplateRef<unknown>;
         }

         @Component({
           selector: 'creator',
           template: '<menu-trigger></menu-trigger>',
           providers: [{provide: creatorToken, useValue: 'hello from creator'}]
         })
         class Creator {
           @ViewChild(MenuTrigger) trigger!: MenuTrigger;
         }

         @Component({
           template: `
              <declarer></declarer>
              <creator></creator>
            `
         })
         class App {
           @ViewChild(Declarer) declarer!: Declarer;
           @ViewChild(Creator) creator!: Creator;
         }

         TestBed.configureTestingModule(
             {declarations: [App, MenuTrigger, Menu, Declarer, Creator]});
         const injector = Injector.create({providers: [{provide: token, useValue: 'hello'}]});
         const fixture = TestBed.createComponent(App);
         fixture.detectChanges();
         const {declarer, creator} = fixture.componentInstance;

         creator.trigger.menu = declarer.template;
         creator.trigger.open(injector);
         fixture.detectChanges();

         expect(declarer.menu.tokenValue).toBe('hello');
         expect(declarer.menu.declarerTokenValue).toBe('hello from declarer');
         expect(declarer.menu.creatorTokenValue).toBeNull();
       });

    it('should give precedence to value provided lower in the tree over custom injector', () => {
      @Directive({selector: 'menu'})
      class Menu {
        constructor(@Inject(token) public tokenValue: string) {}
      }

      @Directive({
        selector: '[provide-token]',
        providers: [{provide: token, useValue: 'hello from directive'}]
      })
      class ProvideToken {
      }

      @Component({
        template: `
          <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
          <ng-template #menuTemplate>
            <section>
              <div provide-token>
                <menu></menu>
              </div>
            </section>
          </ng-template>
        `,
        providers: [{provide: token, useValue: 'hello from parent'}]
      })
      class App {
        @ViewChild(MenuTrigger) trigger!: MenuTrigger;
        @ViewChild(Menu) menu!: Menu;
      }

      @NgModule({
        declarations: [App, MenuTrigger, Menu, ProvideToken],
        exports: [App, MenuTrigger, Menu, ProvideToken],
      })
      class Module {
      }

      TestBed.configureTestingModule({imports: [Module]});
      const injector =
          Injector.create({providers: [{provide: token, useValue: 'hello from injector'}]});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      fixture.componentInstance.trigger.open(injector);
      fixture.detectChanges();

      expect(fixture.componentInstance.menu.tokenValue).toBe('hello from directive');
    });

    it('should give precedence to value provided in custom injector over one provided higher',
       () => {
         @Directive({selector: 'menu'})
         class Menu {
           constructor(@Inject(token) public tokenValue: string) {}
         }

         @Directive({
           selector: '[provide-token]',
           providers: [{provide: token, useValue: 'hello from directive'}]
         })
         class ProvideToken {
         }

         @Component({
           template: `
              <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
              <div provide-token>
                <ng-template #menuTemplate>
                  <menu></menu>
                </ng-template>
              </div>
            `,
           providers: [{provide: token, useValue: 'hello from parent'}]
         })
         class App {
           @ViewChild(MenuTrigger) trigger!: MenuTrigger;
           @ViewChild(Menu) menu!: Menu;
         }

         @NgModule({
           declarations: [App, MenuTrigger, Menu, ProvideToken],
           exports: [App, MenuTrigger, Menu, ProvideToken],
         })
         class Module {
         }

         TestBed.configureTestingModule({imports: [Module]});
         const injector =
             Injector.create({providers: [{provide: token, useValue: 'hello from injector'}]});
         const fixture = TestBed.createComponent(App);
         fixture.detectChanges();

         fixture.componentInstance.trigger.open(injector);
         fixture.detectChanges();

         expect(fixture.componentInstance.menu.tokenValue).toBe('hello from injector');
       });

    it('should give precedence to value provided lower in the tree over custom injector when crossing view boundaries',
       () => {
         @Directive({selector: 'menu'})
         class Menu {
           constructor(@Inject(token) public tokenValue: string) {}
         }

         @Directive({
           selector: '[provide-token]',
           providers: [{provide: token, useValue: 'hello from directive'}]
         })
         class ProvideToken {
         }

         @Component({selector: 'wrapper', template: `<div><menu></menu></div>`})
         class Wrapper {
           @ViewChild(Menu) menu!: Menu;
         }

         @Component({
           template: `
              <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
              <ng-template #menuTemplate>
                <section provide-token>
                  <wrapper></wrapper>
                </section>
              </ng-template>
            `,
           providers: [{provide: token, useValue: 'hello from parent'}]
         })
         class App {
           @ViewChild(MenuTrigger) trigger!: MenuTrigger;
           @ViewChild(Wrapper) wrapper!: Wrapper;
         }

         @NgModule({
           declarations: [App, MenuTrigger, Menu, ProvideToken, Wrapper],
           exports: [App, MenuTrigger, Menu, ProvideToken, Wrapper],
         })
         class Module {
         }

         TestBed.configureTestingModule({imports: [Module]});
         const injector =
             Injector.create({providers: [{provide: token, useValue: 'hello from injector'}]});
         const fixture = TestBed.createComponent(App);
         fixture.detectChanges();

         fixture.componentInstance.trigger.open(injector);
         fixture.detectChanges();

         expect(fixture.componentInstance.wrapper.menu.tokenValue).toBe('hello from directive');
       });

    it('should give precedence to value provided in custom injector over one provided higher when crossing view boundaries',
       () => {
         @Directive({selector: 'menu'})
         class Menu {
           constructor(@Inject(token) public tokenValue: string) {}
         }

         @Directive({
           selector: '[provide-token]',
           providers: [{provide: token, useValue: 'hello from directive'}]
         })
         class ProvideToken {
         }

         @Component({selector: 'wrapper', template: `<div><menu></menu></div>`})
         class Wrapper {
           @ViewChild(Menu) menu!: Menu;
         }


         @Component({
           template: `
              <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
              <div provide-token>
                <ng-template #menuTemplate>
                  <wrapper></wrapper>
                </ng-template>
              </div>
            `,
           providers: [{provide: token, useValue: 'hello from parent'}]
         })
         class App {
           @ViewChild(MenuTrigger) trigger!: MenuTrigger;
           @ViewChild(Wrapper) wrapper!: Wrapper;
         }

         @NgModule({
           declarations: [App, MenuTrigger, Menu, ProvideToken, Wrapper],
           exports: [App, MenuTrigger, Menu, ProvideToken, Wrapper],
         })
         class Module {
         }

         TestBed.configureTestingModule({imports: [Module]});
         const injector =
             Injector.create({providers: [{provide: token, useValue: 'hello from injector'}]});
         const fixture = TestBed.createComponent(App);
         fixture.detectChanges();

         fixture.componentInstance.trigger.open(injector);
         fixture.detectChanges();

         expect(fixture.componentInstance.wrapper.menu.tokenValue).toBe('hello from injector');
       });

    it('should not resolve value at insertion location', () => {
      @Directive({selector: 'menu'})
      class Menu {
        constructor(@Inject(token) public tokenValue: string) {}
      }

      @Directive({
        selector: '[provide-token]',
        providers: [{provide: token, useValue: 'hello from directive'}]
      })
      class ProvideToken {
      }

      @Component({
        template: `
          <div provide-token>
            <menu-trigger [triggerFor]="menuTemplate"></menu-trigger>
          </div>

          <ng-template #menuTemplate>
            <menu></menu>
          </ng-template>
        `,
        providers: [{provide: token, useValue: 'hello from parent'}]
      })
      class App {
        @ViewChild(MenuTrigger) trigger!: MenuTrigger;
        @ViewChild(Menu) menu!: Menu;
      }

      @NgModule({
        declarations: [App, MenuTrigger, Menu, ProvideToken],
        exports: [App, MenuTrigger, Menu, ProvideToken],
      })
      class Module {
      }

      TestBed.configureTestingModule({imports: [Module]});
      // Provide an empty injector so we hit the new code path.
      const injector = Injector.create({providers: []});
      const fixture = TestBed.createComponent(App);
      fixture.detectChanges();

      fixture.componentInstance.trigger.open(injector);
      fixture.detectChanges();

      expect(fixture.componentInstance.menu.tokenValue).toBe('hello from parent');
    });
  });

  it('should prioritize module providers over additional providers', () => {
    const token = new InjectionToken('token');

    @NgModule({providers: [{provide: token, useValue: 'module'}]})
    class ModuleWithProvider {
    }

    const injector =
        createInjector(ModuleWithProvider, null, [{provide: token, useValue: 'additional'}]);

    expect(injector.get(token)).toBe('module');
  });
});