fix: the link name should be a required field

frontend/appflowy_flutter/integration_test/desktop/document/document_toolbar_test.dart

@@ -366,5 +366,88 @@ void main() {
       expect(getLinkFromNode(node), link);
       expect(getNodeText(node), afterText);
     });
+
+    testWidgets('insert link and clear link name', (tester) async {
+      const text = 'edit link', link = 'https://test.appflowy.cloud';
+      await prepareForToolbar(tester, text);
+
+      /// tap link button to show CreateLinkMenu
+      final linkButton = find.byFlowySvg(FlowySvgs.toolbar_link_m);
+      await tester.tapButton(linkButton);
+
+      /// search for page and select it
+      final textField = find.descendant(
+        of: find.byType(LinkCreateMenu),
+        matching: find.byType(TextFormField),
+      );
+      await tester.enterText(textField, link);
+      await tester.pumpAndSettle();
+      await tester.simulateKeyEvent(LogicalKeyboardKey.enter);
+      Node node = tester.editor.getNodeAtPath([0]);
+      expect(getLinkFromNode(node), link);
+      await tester.simulateKeyEvent(LogicalKeyboardKey.escape);
+
+      /// hover link
+      await tester.hoverOnWidget(find.byType(LinkHoverTrigger));
+
+      /// click edit button to show LinkEditMenu
+      final editButton = find.byFlowySvg(FlowySvgs.toolbar_link_edit_m);
+      await tester.tapButton(editButton);
+      final linkEditMenu = find.byType(LinkEditMenu);
+      expect(linkEditMenu, findsOneWidget);
+
+      /// clear the link name
+      final titleField = find.descendant(
+        of: linkEditMenu,
+        matching: find.byType(TextFormField),
+      );
+      await tester.enterText(titleField, '');
+      await tester.pumpAndSettle();
+      await tester.simulateKeyEvent(LogicalKeyboardKey.enter);
+      node = tester.editor.getNodeAtPath([0]);
+      expect(getNodeText(node), link);
+    });
+
+    testWidgets('insert link and clear link name and remove link', (tester) async {
+      const text = 'edit link', link = 'https://test.appflowy.cloud';
+      await prepareForToolbar(tester, text);
+
+      /// tap link button to show CreateLinkMenu
+      final linkButton = find.byFlowySvg(FlowySvgs.toolbar_link_m);
+      await tester.tapButton(linkButton);
+
+      /// search for page and select it
+      final textField = find.descendant(
+        of: find.byType(LinkCreateMenu),
+        matching: find.byType(TextFormField),
+      );
+      await tester.enterText(textField, link);
+      await tester.pumpAndSettle();
+      await tester.simulateKeyEvent(LogicalKeyboardKey.enter);
+      Node node = tester.editor.getNodeAtPath([0]);
+      expect(getLinkFromNode(node), link);
+      await tester.simulateKeyEvent(LogicalKeyboardKey.escape);
+
+      /// hover link
+      await tester.hoverOnWidget(find.byType(LinkHoverTrigger));
+
+      /// click edit button to show LinkEditMenu
+      final editButton = find.byFlowySvg(FlowySvgs.toolbar_link_edit_m);
+      await tester.tapButton(editButton);
+      final linkEditMenu = find.byType(LinkEditMenu);
+      expect(linkEditMenu, findsOneWidget);
+
+      /// clear the link name
+      final titleField = find.descendant(
+        of: linkEditMenu,
+        matching: find.byType(TextFormField),
+      );
+      await tester.enterText(titleField, '');
+      await tester.pumpAndSettle();
+      await tester.tapButton(find.byFlowySvg(FlowySvgs.toolbar_link_unlink_m));
+      node = tester.editor.getNodeAtPath([0]);
+      expect(getNodeText(node), link);
+      expect(getLinkFromNode(node), null);
+    });
   });
 }

frontend/appflowy_flutter/lib/plugins/document/presentation/editor_plugins/desktop_toolbar/link/link_extension.dart

@@ -27,11 +27,12 @@ extension LinkExtension on EditorState {
     final node = getNodeAtPath(selection.start.path);
     if (node == null) return;
     final transaction = this.transaction;
+    final linkName = info.name.isEmpty ? info.link : info.name;
     transaction.replaceText(
       node,
       selection.startIndex,
       selection.length,
-      info.name,
+      linkName,
       attributes: info.toAttribute(),
     );
     apply(transaction);

frontend/appflowy_flutter/lib/plugins/document/presentation/editor_plugins/desktop_toolbar/link/link_hover_menu.dart

@@ -186,8 +186,11 @@ class _LinkHoverTriggerState extends State<LinkHoverTrigger> {
         linkInfo: LinkInfo(name: title, link: href, isPage: isPage),
         onDismiss: () => editMenuController.close(),
         onApply: (info) => editorState.applyLink(selection, info),
-        onRemoveLink: (linkinfo) =>
-            onRemoveAndReplaceLink(editorState, selection, linkinfo.name),
+        onRemoveLink: (linkinfo) {
+          final replaceText =
+              linkinfo.name.isEmpty ? linkinfo.link : linkinfo.name;
+          onRemoveAndReplaceLink(editorState, selection, replaceText);
+        },
       ),
       child: child,
     );