fix(core): Fix fixture.detectChanges with autoDetect disabled and zon…

…eless

When disabling autodetect (not recommeneded) with zoneless,
`fixture.detectChanges` would previously not refresh the fixture's component.

packages/core/test/component_fixture_spec.ts

@@ -581,4 +581,20 @@ describe('ComponentFixture with zoneless', () => {
     // still throws if checkNoChanges is not disabled
     expect(() => fixture.detectChanges()).toThrowError(/ExpressionChanged/);
   });
+
+  it('runs change detection when autoDetect is false', () => {
+    @Component({
+      template: '{{thing()}}',
+      standalone: true,
+    })
+    class App {
+      thing = signal(1);
+    }
+
+    const fixture = TestBed.createComponent(App);
+    fixture.autoDetectChanges(false);
+    fixture.componentInstance.thing.set(2);
+    fixture.detectChanges();
+    expect(fixture.nativeElement.innerText).toBe('2');
+  });
 });

packages/core/testing/src/component_fixture.ts

@@ -139,7 +139,14 @@ export class ComponentFixture<T> {
       }
 
       if (this.zonelessEnabled) {
-        this._appRef.tick();
+        try {
+          this._testAppRef.externalTestViews.add(this.componentRef.hostView);
+          this._appRef.tick();
+        } finally {
+          if (!this.autoDetect) {
+            this._testAppRef.externalTestViews.delete(this.componentRef.hostView);
+          }
+        }
       } else {
         // Run the change detection inside the NgZone so that any async tasks as part of the change
         // detection are captured by the zone and can be waited for in isStable.