`isSuccess()` not triggering `effect()` during testing

[JPtenBerge]

Describe the bug

I have this AppComponent, with an effect() that's dependent on the isSuccess() of a query:

@Component({
	selector: 'app-root',
	templateUrl: './app.html',
	imports: [ReactiveFormsModule],
	styleUrl: './app.css',
	changeDetection: ChangeDetectionStrategy.OnPush,
})
export class App {
	dataService = inject(DataService);

	formField = new FormControl<number>(42);

	query = injectQuery(() => ({
		queryKey: ['query'],
		queryFn: () => {
			console.log('in query', this.dataService.give());
			return this.dataService.give();
		},
	}));

	constructor() {
		effect(() => {
			console.log('in effect:', this.query.isSuccess());
			if (!this.query.isSuccess()) return;

			console.log('setting form value');
			this.formField.setValue(9999);
		});
	}
}

And I'm trying to test this, either through the classic TestBed or new Vitest features combined with the Testing Library:

describe('App', () => {
	let dataServiceMock: Mocked<DataService>;

	beforeEach(() => {
		dataServiceMock = { give: vi.fn().mockReturnValue(Promise.resolve([30, 40, 50])) } as Mocked<DataService>;
	});

	it('should work using the testing library', async () => {
		let sut = await render(App, {
			providers: [provideQueryClient(new QueryClient()), { provide: DataService, useValue: dataServiceMock }],
		});

		await sut.rerender();
		sut.detectChanges();
		await sut.fixture.whenStable();
		await sut.rerender();
		sut.detectChanges();
		await sut.fixture.whenStable();
		await sut.rerender();
		sut.detectChanges();
		await sut.fixture.whenStable();
		await sut.rerender();
		sut.detectChanges();
		await sut.fixture.whenStable();
		await sut.rerender();
		TestBed.tick();
		TestBed.tick();
		TestBed.tick();
		sut.fixture.detectChanges();
		await sut.fixture.whenStable();
		sut.detectChanges();
		await sut.fixture.whenStable();
		await sut.rerender();
		await expect(page.getByRole('textbox')).toHaveValue(9999);
		expect(sut.fixture.componentInstance.formField.value).toBe(9999);
	});

	it('should work using TestBed', async () => {
		TestBed.configureTestingModule({
			imports: [App],
			providers: [provideQueryClient(new QueryClient()), { provide: DataService, useValue: dataServiceMock }],
		});
		let fixture = TestBed.createComponent(App);
		let sut = fixture.componentInstance;

		fixture.detectChanges();
		await fixture.whenStable();
		fixture.detectChanges();
		await fixture.whenStable();
		fixture.detectChanges();
		await fixture.whenStable();
		TestBed.tick();
		TestBed.tick();
		TestBed.tick();
		TestBed.tick();
		fixture.detectChanges();
		await fixture.whenStable();

		expect(sut.formField.value).toBe(9999);
	});
});

But isSuccess() in the effect() never becomes true even though I'm clearly returning data. I've logged the result of the DataService, it's returning a fulfilled promise as arranged.

The many tick()/detectChanges()/whenStable() are my desperate attempts at getting something to work btw.

This may have something to do with the issue of requiring Angular v19+ and relying on component effect schedule timing.

Your minimal, reproducible example

https://github.com/JPtenBerge/tanstack-query-query-effect-bug

Steps to reproduce

1. Define a query using injectQuery() that on init calls some sort of a service for retrieving data
2. In the constructor, creating an effect() that updates something like a component variable if isSuccess() of the above defined query.
3. In a Vitest browser-based test, configure the testing module with a mock for the above mentioned data service.
4. Assert whether the component variable or something similar has been updated.

Vitest config in angular.json:

"test": {
  "builder": "@angular/build:unit-test",
  "options": {
    "browsers": ["chromium"]
  }
}

Expected behavior

I expect the effect() to be called again and seeing isSuccess() of the query being true, but it's not called again.

How often does this bug happen?

Every time

Screenshots or Videos

No response

Platform

• OS: Windows 11
• Browser: Chromium for testing

Tanstack Query adapter

angular-query

TanStack Query version

v5.90.16

TypeScript version

v5.9.2

Additional context

No response

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🔗 Similar Issues

Possible Duplicates

• Reading out query signals in template causes test failure #9910

🔗 Related PRs

#8690 - [WIP] Angular injectQueries fixes [merged]
#9666 - feat(angular-query): integrate with Angular v19+ PendingTasks for whenStable() support [merged]
#9692 - chore: update svelte examples and tests from runes PR [merged]
#9772 - fix(core): observing "promise" needs to implicitly observe "data" [merged]
TanStack/router#5802 - test(router, start): query navigation transitions [merged]

👤 Suggested Assignees

• JPtenBerge
• crutchcorn
• arnoud-dv
• lachlancollins
• TkDodo

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[TkDodo]

@arnoud-dv FYI

[JPtenBerge]

Any updates by any chance?