90252: Remove old cleanup code

& add tests to confirm that DataService.delete is called

src/app/access-control/group-registry/groups-registry.component.spec.ts

@@ -31,6 +31,7 @@ import { RouterMock } from '../../shared/mocks/router.mock';
 import { PaginationService } from '../../core/pagination/pagination.service';
 import { PaginationServiceStub } from '../../shared/testing/pagination-service.stub';
 import { FeatureID } from '../../core/data/feature-authorization/feature-id';
+import { NoContent } from '../../core/shared/NoContent.model';
 
 describe('GroupRegistryComponent', () => {
   let component: GroupsRegistryComponent;
@@ -145,7 +146,10 @@ describe('GroupRegistryComponent', () => {
           totalPages: 1,
           currentPage: 1
         }), [result]));
-      }
+      },
+      delete(objectId: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+        return createSuccessfulRemoteDataObject$({});
+      },
     };
     dsoDataServiceStub = {
       findByHref(href: string): Observable<RemoteData<DSpaceObject>> {
@@ -301,4 +305,29 @@ describe('GroupRegistryComponent', () => {
       });
     });
   });
+
+  describe('delete', () => {
+    let deleteButton;
+
+    beforeEach(fakeAsync(() => {
+      spyOn(groupsDataServiceStub, 'delete').and.callThrough();
+
+      setIsAuthorized(true, true);
+
+      // force rerender after setup changes
+      component.search({ query: '' });
+      tick();
+      fixture.detectChanges();
+
+      // only mockGroup[0] is deletable, so we should only get one button
+      deleteButton = fixture.debugElement.query(By.css('.btn-delete')).nativeElement;
+    }));
+
+    it('should call GroupDataService.delete', () => {
+      deleteButton.click();
+      fixture.detectChanges();
+
+      expect(groupsDataServiceStub.delete).toHaveBeenCalledWith(mockGroups[0].id);
+    });
+  });
 });