fix(core): queries not matching string injection tokens (angular#38321)

Queries weren't matching directives that provide themselves via string
injection tokens, because the assumption was that any string passed to
a query decorator refers to a template reference.

These changes make it so we match both template references and
providers while giving precedence to the template references.

Fixes angular#38313.
Fixes angular#38315.

PR Close angular#38321

Author: crisbeto

packages/core/src/render3/di.ts

@@ -495,8 +495,8 @@ function searchTokensOnInjector<T>(
  * @returns Index of a found directive or provider, or null when none found.
  */
 export function locateDirectiveOrProvider<T>(
-    tNode: TNode, tView: TView, token: Type<T>|InjectionToken<T>, canAccessViewProviders: boolean,
-    isHostSpecialCase: boolean|number): number|null {
+    tNode: TNode, tView: TView, token: Type<T>|InjectionToken<T>|string,
+    canAccessViewProviders: boolean, isHostSpecialCase: boolean|number): number|null {
   const nodeProviderIndexes = tNode.providerIndexes;
   const tInjectables = tView.data;
 
@@ -510,7 +510,8 @@ export function locateDirectiveOrProvider<T>(
   // When the host special case applies, only the viewProviders and the component are visible
   const endIndex = isHostSpecialCase ? injectablesStart + cptViewProvidersCount : directiveEnd;
   for (let i = startingIndex; i < endIndex; i++) {
-    const providerTokenOrDef = tInjectables[i] as InjectionToken<any>| Type<any>| DirectiveDef<any>;
+    const providerTokenOrDef =
+        tInjectables[i] as InjectionToken<any>| Type<any>| DirectiveDef<any>| string;
     if (i < directivesStart && token === providerTokenOrDef ||
         i >= directivesStart && (providerTokenOrDef as DirectiveDef<any>).type === token) {
       return i;

packages/core/src/render3/query.ts

@@ -227,20 +227,23 @@ class TQuery_ implements TQuery {
   }
 
   private matchTNode(tView: TView, tNode: TNode): void {
-    if (Array.isArray(this.metadata.predicate)) {
-      const localNames = this.metadata.predicate;
-      for (let i = 0; i < localNames.length; i++) {
-        this.matchTNodeWithReadOption(tView, tNode, getIdxOfMatchingSelector(tNode, localNames[i]));
+    const predicate = this.metadata.predicate;
+    if (Array.isArray(predicate)) {
+      for (let i = 0; i < predicate.length; i++) {
+        const name = predicate[i];
+        this.matchTNodeWithReadOption(tView, tNode, getIdxOfMatchingSelector(tNode, name));
+        // Also try matching the name to a provider since strings can be used as DI tokens too.
+        this.matchTNodeWithReadOption(
+            tView, tNode, locateDirectiveOrProvider(tNode, tView, name, false, false));
       }
     } else {
-      const typePredicate = this.metadata.predicate as any;
-      if (typePredicate === ViewEngine_TemplateRef) {
+      if ((predicate as any) === ViewEngine_TemplateRef) {
         if (tNode.type === TNodeType.Container) {
           this.matchTNodeWithReadOption(tView, tNode, -1);
         }
       } else {
         this.matchTNodeWithReadOption(
-            tView, tNode, locateDirectiveOrProvider(tNode, tView, typePredicate, false, false));
+            tView, tNode, locateDirectiveOrProvider(tNode, tView, predicate, false, false));
       }
     }
   }

packages/core/test/acceptance/query_spec.ts

@@ -1631,6 +1631,179 @@ describe('query logic', () => {
       expect(groups[2]).toBeUndefined();
     });
   });
+
+  describe('querying for string token providers', () => {
+    @Directive({
+      selector: '[text-token]',
+      providers: [{provide: 'Token', useExisting: TextTokenDirective}],
+    })
+    class TextTokenDirective {
+    }
+
+    it('should match string injection token in a ViewChild query', () => {
+      @Component({template: '<div text-token></div>'})
+      class App {
+        @ViewChild('Token') token: any;
+      }
+
+      TestBed.configureTestingModule({declarations: [App, TextTokenDirective]});
+      const fixture = TestBed.createComponent(App);
+      fixture.detectChanges();
+      expect(fixture.componentInstance.token).toBeAnInstanceOf(TextTokenDirective);
+    });
+
+    it('should give precedence to local reference if both a reference and a string injection token provider match a ViewChild query',
+       () => {
+         @Component({template: '<div text-token #Token></div>'})
+         class App {
+           @ViewChild('Token') token: any;
+         }
+
+         TestBed.configureTestingModule({declarations: [App, TextTokenDirective]});
+         const fixture = TestBed.createComponent(App);
+         fixture.detectChanges();
+         expect(fixture.componentInstance.token).toBeAnInstanceOf(ElementRef);
+       });
+
+    it('should match string injection token in a ViewChildren query', () => {
+      @Component({template: '<div text-token></div>'})
+      class App {
+        @ViewChildren('Token') tokens!: QueryList<any>;
+      }
+
+      TestBed.configureTestingModule({declarations: [App, TextTokenDirective]});
+      const fixture = TestBed.createComponent(App);
+      fixture.detectChanges();
+
+      const tokens = fixture.componentInstance.tokens;
+      expect(tokens.length).toBe(1);
+      expect(tokens.first).toBeAnInstanceOf(TextTokenDirective);
+    });
+
+    it('should match both string injection token and local reference inside a ViewChildren query',
+       () => {
+         @Component({template: '<div text-token #Token></div>'})
+         class App {
+           @ViewChildren('Token') tokens!: QueryList<any>;
+         }
+
+         TestBed.configureTestingModule({declarations: [App, TextTokenDirective]});
+         const fixture = TestBed.createComponent(App);
+         fixture.detectChanges();
+
+         expect(fixture.componentInstance.tokens.toArray()).toEqual([
+           jasmine.any(ElementRef), jasmine.any(TextTokenDirective)
+         ]);
+       });
+
+    it('should match string injection token in a ContentChild query', () => {
+      @Component({selector: 'has-query', template: '<ng-content></ng-content>'})
+      class HasQuery {
+        @ContentChild('Token') token: any;
+      }
+
+      @Component({template: '<has-query><div text-token></div></has-query>'})
+      class App {
+        @ViewChild(HasQuery) queryComp!: HasQuery;
+      }
+
+      TestBed.configureTestingModule({declarations: [App, HasQuery, TextTokenDirective]});
+      const fixture = TestBed.createComponent(App);
+      fixture.detectChanges();
+
+      expect(fixture.componentInstance.queryComp.token).toBeAnInstanceOf(TextTokenDirective);
+    });
+
+    it('should give precedence to local reference if both a reference and a string injection token provider match a ContentChild query',
+       () => {
+         @Component({selector: 'has-query', template: '<ng-content></ng-content>'})
+         class HasQuery {
+           @ContentChild('Token') token: any;
+         }
+
+         @Component({template: '<has-query><div text-token #Token></div></has-query>'})
+         class App {
+           @ViewChild(HasQuery) queryComp!: HasQuery;
+         }
+
+         TestBed.configureTestingModule({declarations: [App, HasQuery, TextTokenDirective]});
+         const fixture = TestBed.createComponent(App);
+         fixture.detectChanges();
+
+         expect(fixture.componentInstance.queryComp.token).toBeAnInstanceOf(ElementRef);
+       });
+
+    it('should match string injection token in a ContentChildren query', () => {
+      @Component({selector: 'has-query', template: '<ng-content></ng-content>'})
+      class HasQuery {
+        @ContentChildren('Token') tokens!: QueryList<any>;
+      }
+
+      @Component({template: '<has-query><div text-token></div></has-query>'})
+      class App {
+        @ViewChild(HasQuery) queryComp!: HasQuery;
+      }
+
+      TestBed.configureTestingModule({declarations: [App, HasQuery, TextTokenDirective]});
+      const fixture = TestBed.createComponent(App);
+      fixture.detectChanges();
+
+      const tokens = fixture.componentInstance.queryComp.tokens;
+      expect(tokens.length).toBe(1);
+      expect(tokens.first).toBeAnInstanceOf(TextTokenDirective);
+    });
+
+    it('should match both string injection token and local reference inside a ContentChildren query',
+       () => {
+         @Component({selector: 'has-query', template: '<ng-content></ng-content>'})
+         class HasQuery {
+           @ContentChildren('Token') tokens!: QueryList<any>;
+         }
+
+         @Component({template: '<has-query><div text-token #Token></div></has-query>'})
+         class App {
+           @ViewChild(HasQuery) queryComp!: HasQuery;
+         }
+
+         TestBed.configureTestingModule({declarations: [App, HasQuery, TextTokenDirective]});
+         const fixture = TestBed.createComponent(App);
+         fixture.detectChanges();
+
+         expect(fixture.componentInstance.queryComp.tokens.toArray()).toEqual([
+           jasmine.any(ElementRef), jasmine.any(TextTokenDirective)
+         ]);
+       });
+
+    it('should match string token specified through the `read` option of a view query', () => {
+      @Component({template: '<div text-token #Token></div>'})
+      class App {
+        @ViewChild('Token', {read: 'Token'}) token: any;
+      }
+
+      TestBed.configureTestingModule({declarations: [App, TextTokenDirective]});
+      const fixture = TestBed.createComponent(App);
+      fixture.detectChanges();
+      expect(fixture.componentInstance.token).toBeAnInstanceOf(TextTokenDirective);
+    });
+
+    it('should match string token specified through the `read` option of a content query', () => {
+      @Component({selector: 'has-query', template: '<ng-content></ng-content>'})
+      class HasQuery {
+        @ContentChild('Token', {read: 'Token'}) token: any;
+      }
+
+      @Component({template: '<has-query><div text-token #Token></div></has-query>'})
+      class App {
+        @ViewChild(HasQuery) queryComp!: HasQuery;
+      }
+
+      TestBed.configureTestingModule({declarations: [App, HasQuery, TextTokenDirective]});
+      const fixture = TestBed.createComponent(App);
+      fixture.detectChanges();
+
+      expect(fixture.componentInstance.queryComp.token).toBeAnInstanceOf(TextTokenDirective);
+    });
+  });
 });
 
 function initWithTemplate(compType: Type<any>, template: string) {