fix: selection race condition (#1194)

* fix: guard debounced desktop selection update

Avoid dereferencing a cleared selection from the delayed
macOS metrics callback and add a regression test that
covers the stale-timer path.

* chore: clean up analyzer warnings

Remove redundant default arguments in tests and apply the
missing trailing comma required by the current lint rules.

lib/src/editor/editor_component/service/selection/desktop_selection_service.dart

@@ -81,7 +81,13 @@ class _DesktopSelectionServiceWidgetState
       Debounce.debounce(
         'didChangeMetrics - update selection ',
         const Duration(milliseconds: 100),
-        () => updateSelection(currentSelection.value!),
+        () {
+          final selection = currentSelection.value;
+          if (!mounted || selection == null) {
+            return;
+          }
+          updateSelection(selection);
+        },
       );
     }
   }

test/editor/editor_component/service/auto_scroller_test.dart

@@ -54,7 +54,6 @@ void main() {
 
         scroller.startAutoScroll(
           offset,
-          edgeOffset: edgeOffset,
           direction: AxisDirection.up,
         );
 
@@ -96,7 +95,6 @@ void main() {
 
         scroller.startAutoScroll(
           offset,
-          edgeOffset: edgeOffset,
           direction: AxisDirection.down,
         );
 

test/editor/editor_component/service/desktop_selection_service_test.dart

@@ -0,0 +1,42 @@
+import 'dart:ui';
+
+import 'package:appflowy_editor/appflowy_editor.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import '../../../test_helper.dart';
+
+void main() {
+  group('DesktopSelectionServiceWidget', () {
+    testWidgets(
+      'does not crash when selection is cleared before metric debounce fires',
+      (tester) async {
+        final editorState = EditorState(document: Document.blank());
+
+        addTearDown(tester.view.resetPhysicalSize);
+        addTearDown(tester.view.resetDevicePixelRatio);
+
+        tester.view.devicePixelRatio = 1.0;
+
+        await tester.buildAndPump(
+          AppFlowyEditor(
+            editorState: editorState,
+          ),
+        );
+
+        editorState.selectionService.updateSelection(
+          Selection.collapsed(Position(path: [0])),
+        );
+        await tester.pump();
+
+        tester.view.physicalSize = const Size(1600, 1200);
+        await tester.pump();
+
+        editorState.selection = null;
+        await tester.pump(const Duration(milliseconds: 101));
+
+        expect(tester.takeException(), isNull);
+        expect(editorState.selectionService.currentSelection.value, isNull);
+      },
+    );
+  });
+}

test/legacy/undo_manager_test.dart

@@ -427,7 +427,6 @@ void main() async {
       transaction,
       options: const ApplyOptions(
         recordUndo: false,
-        recordRedo: false,
         source: TransactionSource.none,
       ),
     );

test/new/service/shortcuts/command_shortcut_events/undo_redo_command_test.dart

@@ -203,7 +203,7 @@ void main() async {
 
       // Place cursor at [0] offset 0
       await editor.updateSelection(
-        Selection.collapsed(Position(path: [0], offset: 0)),
+        Selection.collapsed(Position(path: [0])),
       );
 
       // Type 4 characters with pumpAndSettle between each