tests: add chat model tests(cv: 100)

test/dashbot/models/chat_action_model_test.dart

@@ -0,0 +1,45 @@
+import 'package:apidash/dashbot/core/constants/constants.dart';
+import 'package:apidash/dashbot/features/chat/models/chat_action.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('ChatAction serialization & defaults', () {
+    test('fromJson (full) -> correct enum mapping', () {
+      final json = {
+        'action': 'apply_openapi',
+        'target': 'documentation',
+        'field': 'spec',
+        'path': '/components/schemas',
+        'value': {'k': 'v'},
+      };
+      final action = ChatAction.fromJson(json);
+      expect(action.actionType, ChatActionType.applyOpenApi);
+      expect(action.targetType, ChatActionTarget.documentation);
+      expect(action.field, 'spec');
+      expect(action.path, '/components/schemas');
+      expect(action.value, {'k': 'v'});
+    });
+
+    test('fromJson (missing fields) -> uses safe defaults', () {
+      final action = ChatAction.fromJson({});
+      expect(action.actionType, ChatActionType.other);
+      expect(action.targetType, ChatActionTarget.httpRequestModel);
+      expect(action.field, '');
+      expect(action.path, isNull);
+    });
+
+    test('toJson produces expected keys & enum strings', () {
+      const action = ChatAction(
+        action: 'download_doc',
+        target: 'documentation',
+        actionType: ChatActionType.downloadDoc,
+        targetType: ChatActionTarget.documentation,
+      );
+      final json = action.toJson();
+      expect(json, containsPair('action', 'download_doc'));
+      expect(json, containsPair('target', 'documentation'));
+      expect(json, containsPair('action_type', 'download_doc'));
+      expect(json, containsPair('target_type', 'documentation'));
+    });
+  });
+}