优化 demo

apps/im_app/lib/features/chat/presentation/chat_db_test_state.dart

@@ -0,0 +1,39 @@
+// 数据库测试页状态（Demo，正式开发后随页面一并删除）
+
+/// 单条测试结果记录
+class TestResult {
+  final String title;
+  final String subtitle;
+  final String duration;
+
+  TestResult({
+    required this.title,
+    required this.subtitle,
+    required this.duration,
+  });
+}
+
+class ChatDbTestState {
+  final bool testStarted;
+  final List<TestResult> testResults;
+  final String currentState;
+
+  const ChatDbTestState({
+    this.testStarted = false,
+    this.testResults = const [],
+    this.currentState = '',
+  });
+
+  /// 按钮文案（Widget 直接读，不在 View 层做判断）
+  String get buttonLabel => testStarted ? '结束' : '开始';
+
+  ChatDbTestState copyWith({
+    bool? testStarted,
+    List<TestResult>? testResults,
+    String? currentState,
+  }) => ChatDbTestState(
+    testStarted: testStarted ?? this.testStarted,
+    testResults: testResults ?? this.testResults,
+    currentState: currentState ?? this.currentState,
+  );
+}

apps/im_app/lib/features/chat/presentation/chat_db_test_view_model.dart

@@ -6,42 +6,12 @@ import 'package:im_app/app/di/db_provider.dart';
 import 'package:im_app/data/local/drift/app_database.dart';
 import 'package:riverpod_annotation/riverpod_annotation.dart';
 
+import 'chat_db_test_state.dart';
+
+export 'chat_db_test_state.dart';
+
 part 'chat_db_test_view_model.g.dart';
 
-class TestResult {
-  final String title;
-  final String subtitle;
-  final String duration;
-
-  TestResult({
-    required this.title,
-    required this.subtitle,
-    required this.duration,
-  });
-}
-
-class ChatDbTestState {
-  final bool testStarted;
-  final List<TestResult> testResults;
-  final String currentState;
-
-  const ChatDbTestState({
-    this.testStarted = false,
-    this.testResults = const [],
-    this.currentState = '',
-  });
-
-  ChatDbTestState copyWith({
-    bool? testStarted,
-    List<TestResult>? testResults,
-    String? currentState,
-  }) => ChatDbTestState(
-    testStarted: testStarted ?? this.testStarted,
-    testResults: testResults ?? this.testResults,
-    currentState: currentState ?? this.currentState,
-  );
-}
-
 @riverpod
 class ChatDbTestViewModel extends _$ChatDbTestViewModel {
   @override

apps/im_app/lib/features/chat/view/chat_db_test_page.dart

@@ -30,7 +30,7 @@ class ChatDbTestPage extends ConsumerWidget {
               mainAxisAlignment: MainAxisAlignment.spaceBetween,
               children: [
                 AppButton.inverse(
-                  label: state.testStarted ? '结束' : '开始',
+                  label: state.buttonLabel,
                   onPressed: () => vm.toggleDBTest(),
                 ),
                 SizedBox(width: 8),