[lexical-selection]: Fix applying styles for empty table cells

packages/lexical-selection/src/lexical-node.ts

@@ -333,6 +333,26 @@ export function $patchStyleText(
   $forEachSelectedTextNode((textNode) => {
     $patchStyle(textNode, patch);
   });
+
+  const nodes = selection.getNodes();
+  if (nodes.length > 0) {
+    const patchedElementKeys = new Set<NodeKey>();
+    for (const node of nodes) {
+      if (
+        !$isElementNode(node) ||
+        !node.canBeEmpty() ||
+        node.getChildrenSize() !== 0
+      ) {
+        continue;
+      }
+      const key = node.getKey();
+      if (patchedElementKeys.has(key)) {
+        continue;
+      }
+      patchedElementKeys.add(key);
+      $patchStyle(node, patch);
+    }
+  }
 }
 
 export function $forEachSelectedTextNode(

packages/lexical-table/src/__tests__/unit/LexicalTableSelection.test.tsx

@@ -24,6 +24,8 @@ import {
   $createTextNode,
   $getRoot,
   $getSelection,
+  $isParagraphNode,
+  $isTextNode,
   $setSelection,
 } from 'lexical';
 import {initializeUnitTest} from 'lexical/src/__tests__/utils';
@@ -87,6 +89,39 @@ describe('table selection', () => {
           {discrete: true},
         );
       });
+
+      test('$patchStyleText applies styles to empty table cells', () => {
+        testEnv.editor.update(
+          () => {
+            const selection = $getSelection();
+            expect($isTableSelection(selection)).toBe(true);
+
+            const emptyCell = tableMap.at(0)!.at(0)!.cell;
+            const emptyParagraph = emptyCell.getFirstChild();
+            if (!$isParagraphNode(emptyParagraph)) {
+              throw new Error('Expected paragraph node in empty cell');
+            }
+            emptyParagraph.clear();
+            expect(emptyParagraph.getChildrenSize()).toBe(0);
+
+            $patchStyleText(selection!, {color: 'blue'});
+
+            const filledCell = tableMap.at(0)!.at(1)!.cell;
+            const filledParagraph = filledCell.getFirstChild();
+            if (!$isParagraphNode(filledParagraph)) {
+              throw new Error('Expected paragraph node in filled cell');
+            }
+            const textNode = filledParagraph.getFirstChild();
+            if (!$isTextNode(textNode)) {
+              throw new Error('Expected text node inside filled cell');
+            }
+
+            expect(textNode.getStyle()).toBe('color: blue;');
+            expect(emptyParagraph.getTextStyle()).toBe('color: blue;');
+          },
+          {discrete: true},
+        );
+      });
     });
 
     describe('regression #7140', () => {