Fix workspace list always render

Signed-off-by: Lin Wang <wonglam@amazon.com>

src/plugins/workspace/public/components/workspace_list/index.tsx

@@ -17,7 +17,7 @@ import {
 import useObservable from 'react-use/lib/useObservable';
 import { of } from 'rxjs';
 import { i18n } from '@osd/i18n';
-import { debounce } from '../../../../../core/public';
+import { debounce, WorkspaceObject } from '../../../../../core/public';
 import { WorkspaceAttribute } from '../../../../../core/public';
 import { useOpenSearchDashboards } from '../../../../../plugins/opensearch_dashboards_react/public';
 import { switchWorkspace, updateWorkspace } from '../utils/workspace';
@@ -34,14 +34,19 @@ const WORKSPACE_LIST_PAGE_DESCRIPTIOIN = i18n.translate('workspace.list.descript
     'Workspace allow you to save and organize library items, such as index patterns, visualizations, dashboards, saved searches, and share them with other OpenSearch Dashboards users. You can control which features are visible in each workspace, and which users and groups have read and write access to the library items in the workspace.',
 });
 
+const emptyWorkspaceList: WorkspaceObject[] = [];
+
 export const WorkspaceList = () => {
   const {
     services: { workspaces, application, http },
   } = useOpenSearchDashboards();
 
   const initialSortField = 'name';
   const initialSortDirection = 'asc';
-  const workspaceList = useObservable(workspaces?.workspaceList$ ?? of([]), []);
+  const workspaceList = useObservable(
+    workspaces?.workspaceList$ ?? of(emptyWorkspaceList),
+    emptyWorkspaceList
+  );
   const [queryInput, setQueryInput] = useState<string>('');
   const [pagination, setPagination] = useState({
     pageIndex: 0,

src/plugins/workspace/public/hooks.ts

@@ -8,8 +8,10 @@ import { useMemo } from 'react';
 import { of } from 'rxjs';
 import { ApplicationStart, PublicAppInfo } from '../../../core/public';
 
+const emptyMap = new Map();
+
 export function useApplications(application?: ApplicationStart) {
-  const applications = useObservable(application?.applications$ ?? of(new Map()), new Map());
+  const applications = useObservable(application?.applications$ ?? of(emptyMap), emptyMap);
   return useMemo(() => {
     const apps: PublicAppInfo[] = [];
     applications.forEach((app) => {