Memoize getEntityRecords to prevent infinite re-renders

packages/core-data/src/selectors.js

@@ -18,6 +18,17 @@ import { getQueriedItems } from './queried-data';
 import { DEFAULT_ENTITY_KEY } from './entities';
 import { getNormalizedCommaSeparable } from './utils';
 
+/**
+ * Shared reference to an empty array for cases where it is important to avoid
+ * returning a new array reference on every invocation, as in a connected or
+ * other pure component which performs `shouldComponentUpdate` check on props.
+ * This should be used as a last resort, since the normalized data should be
+ * maintained by the reducer result in state.
+ *
+ * @type {Array}
+ */
+const EMPTY_ARRAY = [];
+
 /**
  * Returns true if a request is in progress for embed preview data, or false
  * otherwise.
@@ -238,7 +249,7 @@ export function getEntityRecords( state, kind, name, query ) {
 		'queriedData',
 	] );
 	if ( ! queriedState ) {
-		return [];
+		return EMPTY_ARRAY;
 	}
 	return getQueriedItems( queriedState, query );
 }

packages/core-data/src/test/selectors.js

@@ -247,6 +247,42 @@ describe( 'getEntityRecords', () => {
 			{ slug: 'page' },
 		] );
 	} );
+
+	it( 'should return the same instance with the same arguments', () => {
+		let state = deepFreeze( {
+			entities: {
+				data: {},
+			},
+		} );
+
+		const postTypeFirstRecords = getEntityRecords(
+			state,
+			'root',
+			'postType'
+		);
+		const wpBlockFirstRecords = getEntityRecords(
+			state,
+			'postType',
+			'wp_block'
+		);
+
+		// Simulate update states
+		state = { ...state };
+
+		const postTypeSecondRecords = getEntityRecords(
+			state,
+			'root',
+			'postType'
+		);
+		const wpBlockSecondRecords = getEntityRecords(
+			state,
+			'postType',
+			'wp_block'
+		);
+
+		expect( postTypeFirstRecords ).toBe( postTypeSecondRecords );
+		expect( wpBlockFirstRecords ).toBe( wpBlockSecondRecords );
+	} );
 } );
 
 describe( '__experimentalGetDirtyEntityRecords', () => {

packages/edit-widgets/src/components/widget-areas-block-editor-provider/index.js

@@ -46,7 +46,8 @@ export default function WidgetAreasBlockEditorProvider( {
 				'postType',
 				'wp_block'
 			),
-		} )
+		} ),
+		[]
 	);
 	const { setIsInserterOpened } = useDispatch( 'core/edit-widgets' );