65272: Existing test fixes

src/app/+item-page/edit-item-page/abstract-item-update/abstract-item-update.component.ts

@@ -57,7 +57,7 @@ export abstract class AbstractItemUpdateComponent implements OnInit {
    */
   ngOnInit(): void {
     observableCombineLatest(this.route.data, this.route.parent.data).pipe(
-      map(([data, parentData]) => Object.assign(data, parentData)),
+      map(([data, parentData]) => Object.assign({}, data, parentData)),
       map((data) => data.item),
       first(),
       map((data: RemoteData<Item>) => data.payload)

src/app/+item-page/edit-item-page/item-metadata/item-metadata.component.spec.ts

@@ -123,6 +123,7 @@ describe('ItemMetadataComponent', () => {
         commitUpdates: {}
       });
       routeStub = {
+        data: observableOf({}),
         parent: {
           data: observableOf({ item: createSuccessfulRemoteDataObject(item) })
         }

src/app/+item-page/edit-item-page/item-relationships/item-relationships.component.spec.ts

@@ -122,6 +122,7 @@ describe('ItemRelationshipsComponent', () => {
       findById: observableOf(new RemoteData(false, false, true, undefined, item))
     });
     routeStub = {
+      data: observableOf({}),
       parent: {
         data: observableOf({ item: new RemoteData(false, false, true, null, item) })
       }