fix: cleanup components without id (#419)

Closes #398

projects/testing-library/src/lib/testing-library.ts

@@ -492,7 +492,10 @@ function cleanupAtFixture(fixture: ComponentFixture<any>) {
 
   if (!fixture.nativeElement.getAttribute('ng-version') && fixture.nativeElement.parentNode === document.body) {
     document.body.removeChild(fixture.nativeElement);
+  } else if (!fixture.nativeElement.getAttribute('id') && document.body.children?.[0] === fixture.nativeElement) {
+    document.body.removeChild(fixture.nativeElement);
   }
+
   mountedFixtures.delete(fixture);
 }
 

projects/testing-library/tests/issues/issue-398-component-without-host-id.spec.ts

@@ -0,0 +1,24 @@
+import { Component } from '@angular/core';
+import { render, screen } from '../../src/public_api';
+
+test('should create the app', async () => {
+  await render(FixtureComponent);
+  expect(screen.getByRole('heading')).toBeInTheDocument();
+});
+
+test('should re-create the app', async () => {
+  await render(FixtureComponent);
+  expect(screen.getByRole('heading')).toBeInTheDocument();
+});
+
+@Component({
+  selector: 'atl-fixture',
+  standalone: true,
+  template: '<h1>My title</h1>',
+  // eslint-disable-next-line @angular-eslint/no-host-metadata-property
+  host: {
+    // eslint-disable-next-line @typescript-eslint/naming-convention
+    '[attr.id]': 'null', // this breaks the cleaning up of tests
+  },
+})
+class FixtureComponent {}