cleanup and added unit tests

hartmann-foto-documentation-frontend/test/controller/login_controller_test.dart

@@ -0,0 +1,80 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:fotodocumentation/controller/login_controller.dart';
+import 'package:fotodocumentation/utils/di_container.dart';
+import 'package:fotodocumentation/utils/http_client_utils.dart';
+import 'package:fotodocumentation/utils/jwt_token_storage.dart';
+import 'package:http/http.dart' as http;
+import 'package:mockito/mockito.dart';
+
+import '../testing/test_http_client_utils.dart';
+import '../testing/test_utils.mocks.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+  DiContainer.instance.initState();
+  var jwtTokenStorage = MockJwtTokenStorage();
+  when(jwtTokenStorage.getAccessToken()).thenAnswer((_) async => null);
+  DiContainer.instance.put(JwtTokenStorage, jwtTokenStorage);
+
+  LoginController controller = LoginControllerImpl();
+
+  group('LoginController', () {
+    test('authenticate returns JwtTokenPairDto on successful login', () async {
+      final client = MockClient();
+      DiContainer.instance.put(HttpClientUtils, TestHttpCLientUtilsImpl(client));
+
+      when(jwtTokenStorage.saveTokens(any, any)).thenAnswer((_) async => {});
+      when(client.get(Uri.parse('http://localhost:8080/api/login'), headers: anyNamed('headers')))
+          .thenAnswer((_) async => http.Response(_jwtTokenPairJson, 200));
+
+      var reply = await controller.authenticate("testuser", "testpass");
+      expect(reply.jwtTokenPairDto, isNotNull);
+      expect(reply.jwtTokenPairDto?.accessToken, "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.access");
+      expect(reply.jwtTokenPairDto?.refreshToken, "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.refresh");
+      verify(jwtTokenStorage.saveTokens(any, any)).called(1);
+    });
+
+
+
+    test('authenticate returns null on authentication failure (401)', () async {
+      final client = MockClient();
+      DiContainer.instance.put(HttpClientUtils, TestHttpCLientUtilsImpl(client));
+
+      when(client.get(Uri.parse('http://localhost:8080/api/login'), headers: anyNamed('headers')))
+          .thenAnswer((_) async => http.Response('Unauthorized', 401));
+
+      var reply = await controller.authenticate("wronguser", "wrongpass");
+      expect(reply.jwtTokenPairDto, isNull);
+      verifyNever(jwtTokenStorage.saveTokens(any, any));
+    });
+
+    test('authenticate returns null on server error (500)', () async {
+      final client = MockClient();
+      DiContainer.instance.put(HttpClientUtils, TestHttpCLientUtilsImpl(client));
+
+      when(client.get(Uri.parse('http://localhost:8080/api/login'), headers: anyNamed('headers')))
+          .thenAnswer((_) async => http.Response('Internal Server Error', 500));
+
+      var reply = await controller.authenticate("testuser", "testpass");
+      expect(reply.jwtTokenPairDto, isNull);
+      verifyNever(jwtTokenStorage.saveTokens(any, any));
+    });
+
+    test('authenticate returns null on exception', () async {
+      final client = MockClient();
+      DiContainer.instance.put(HttpClientUtils, TestHttpCLientUtilsImpl(client));
+
+      when(client.get(Uri.parse('http://localhost:8080/api/login'), headers: anyNamed('headers')))
+          .thenThrow(Exception('Network error'));
+
+      var reply = await controller.authenticate("testuser", "testpass");
+      expect(reply.jwtTokenPairDto, isNull);
+      verifyNever(jwtTokenStorage.saveTokens(any, any));
+    });
+  });
+}
+
+String _jwtTokenPairJson = '''{
+  "accessToken": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.access",
+  "refreshToken": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.refresh"
+}''';