Ensure there is always a Navigation available in the browse mode side…

…bar via fallback algorithm (#50321)

* Normalize menu used in sidebar with fallback algorithm

* Make fallback retrieval invalidate query cache for Navigation entities

* Conditionally trigger fallback creation if no menus are found

* Make code self documenting

packages/core-data/src/resolvers.js

@@ -585,10 +585,14 @@ export const getNavigationFallbackId =
 		dispatch.receiveNavigationFallbackId( fallback?.id );
 
 		if ( record ) {
+			const invalidateNavigationQueries = true;
+
 			dispatch.receiveEntityRecords(
 				'postType',
 				'wp_navigation',
-				record
+				record,
+				undefined,
+				invalidateNavigationQueries
 			);
 
 			// Resolve to avoid further network requests.

packages/edit-site/src/components/sidebar-navigation-screen-navigation-menus/index.js

@@ -2,7 +2,8 @@
  * WordPress dependencies
  */
 import { __, sprintf } from '@wordpress/i18n';
-import { useEntityRecords } from '@wordpress/core-data';
+import { useEntityRecords, store as coreStore } from '@wordpress/core-data';
+import { useSelect } from '@wordpress/data';
 
 import { decodeEntities } from '@wordpress/html-entities';
 import {
@@ -41,15 +42,35 @@ function buildMenuLabel( title, id, status ) {
 }
 
 export default function SidebarNavigationScreenNavigationMenus() {
-	const { records: navigationMenus, isResolving: isLoading } =
-		useEntityRecords(
-			'postType',
-			`wp_navigation`,
-			PRELOADED_NAVIGATION_MENUS_QUERY
-		);
+	const {
+		records: navigationMenus,
+		isResolving: isResolvingNavigationMenus,
+		hasResolved: hasResolvedNavigationMenus,
+	} = useEntityRecords(
+		'postType',
+		`wp_navigation`,
+		PRELOADED_NAVIGATION_MENUS_QUERY
+	);
+
+	const isLoading =
+		isResolvingNavigationMenus && ! hasResolvedNavigationMenus;
+
+	const getNavigationFallbackId = useSelect(
+		( select ) => select( coreStore ).getNavigationFallbackId
+	);
 
 	const firstNavigationMenu = navigationMenus?.[ 0 ];
 
+	// If there is no navigation menu found
+	// then trigger fallback algorithm to create one.
+	if (
+		! firstNavigationMenu &&
+		! isResolvingNavigationMenus &&
+		hasResolvedNavigationMenus
+	) {
+		getNavigationFallbackId();
+	}
+
 	const { handleSave, handleDelete, handleDuplicate } =
 		useNavigationMenuHandlers();