chore(auth): Unit tests for fetchCurrentDevice API

packages/auth/amplify_auth_cognito_dart/lib/src/auth_plugin_impl.dart

@@ -31,6 +31,7 @@ import 'package:amplify_auth_cognito_dart/src/sdk/cognito_identity_provider.dart
         ForgotPasswordRequest,
         GetUserAttributeVerificationCodeRequest,
         GetUserRequest,
+        GetDeviceRequest,
         ListDevicesRequest,
         ResendConfirmationCodeRequest,
         UserContextDataType,
@@ -39,6 +40,7 @@ import 'package:amplify_auth_cognito_dart/src/sdk/cognito_identity_provider.dart
         VerifyUserAttributeRequest;
 import 'package:amplify_auth_cognito_dart/src/sdk/sdk_bridge.dart';
 import 'package:amplify_auth_cognito_dart/src/sdk/src/cognito_identity_provider/model/analytics_metadata_type.dart';
+import 'package:amplify_auth_cognito_dart/src/sdk/src/cognito_identity_provider/model/get_device_response.dart';
 import 'package:amplify_auth_cognito_dart/src/state/cognito_state_machine.dart';
 import 'package:amplify_auth_cognito_dart/src/state/state.dart';
 import 'package:amplify_auth_cognito_dart/src/util/cognito_iam_auth_provider.dart';
@@ -97,6 +99,7 @@ class AmplifyAuthCognitoDart extends AuthPluginInterface
   late CognitoAuthStateMachine _stateMachine = CognitoAuthStateMachine(
     dependencyManager: dependencies,
   );
+
   StreamSubscription<AuthState>? _stateMachineSubscription;
 
   /// The underlying state machine, for use in subclasses.
@@ -993,6 +996,46 @@ class AmplifyAuthCognitoDart extends AuthPluginInterface
         .result;
   }
 
+  @override
+  Future<CognitoDevice> fetchCurrentDevice() async {
+    final tokens = await stateMachine.getUserPoolTokens();
+    final deviceSecrets = await _deviceRepo.get(tokens.username);
+    final deviceKey = deviceSecrets?.deviceKey;
+    if (deviceSecrets == null || deviceKey == null) {
+      throw const DeviceNotTrackedException();
+    }
+
+    late GetDeviceResponse response;
+
+    try {
+      response = await _cognitoIdp
+          .getDevice(
+            cognito.GetDeviceRequest(
+              deviceKey: deviceKey,
+              accessToken: tokens.accessToken.raw,
+            ),
+          )
+          .result;
+    } on Exception catch (error) {
+      throw AuthException.fromException(error);
+    }
+
+    final device = response.device;
+    final attributes =
+        device.deviceAttributes ?? const <cognito.AttributeType>[];
+
+    return CognitoDevice(
+      id: deviceKey,
+      attributes: {
+        for (final attribute in attributes)
+          attribute.name: attribute.value ?? '',
+      },
+      createdDate: device.deviceCreateDate,
+      lastAuthenticatedDate: device.deviceLastAuthenticatedDate,
+      lastModifiedDate: device.deviceLastModifiedDate,
+    );
+  }
+
   @override
   Future<List<CognitoDevice>> fetchDevices() async {
     final allDevices = <CognitoDevice>[];

packages/auth/amplify_auth_cognito_test/test/plugin/fetch_current_device_test.dart

@@ -0,0 +1,99 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import 'package:amplify_auth_cognito_dart/amplify_auth_cognito_dart.dart';
+import 'package:amplify_auth_cognito_dart/src/credentials/cognito_keys.dart';
+import 'package:amplify_auth_cognito_dart/src/credentials/device_metadata_repository.dart';
+import 'package:amplify_auth_cognito_dart/src/sdk/cognito_identity_provider.dart';
+import 'package:amplify_auth_cognito_test/common/mock_clients.dart';
+import 'package:amplify_auth_cognito_test/common/mock_config.dart';
+import 'package:amplify_auth_cognito_test/common/mock_secure_storage.dart';
+import 'package:amplify_core/amplify_core.dart';
+import 'package:test/test.dart';
+
+void main() {
+  AmplifyLogger().logLevel = LogLevel.verbose;
+
+  final userPoolKeys = CognitoUserPoolKeys(userPoolConfig);
+  final identityPoolKeys = CognitoIdentityPoolKeys(identityPoolConfig);
+  final testAuthRepo = AmplifyAuthProviderRepository();
+  final mockDevice = DeviceType(deviceKey: deviceKey);
+  final mockDeviceResponse = GetDeviceResponse(device: mockDevice);
+
+  late DeviceMetadataRepository repo;
+  late AmplifyAuthCognitoDart plugin;
+
+  group('fetchCurrentDevice', () {
+    setUp(() async {
+      final secureStorage = MockSecureStorage();
+      seedStorage(
+        secureStorage,
+        userPoolKeys: userPoolKeys,
+        identityPoolKeys: identityPoolKeys,
+        deviceKeys: CognitoDeviceKeys(userPoolConfig, username),
+      );
+      plugin = AmplifyAuthCognitoDart(
+        secureStorageFactory: (_) => secureStorage,
+      );
+      await plugin.configure(
+        config: mockConfig,
+        authProviderRepo: testAuthRepo,
+      );
+      repo = plugin.stateMachine.getOrCreate<DeviceMetadataRepository>();
+    });
+
+    group('Cognito GetDevice returns successfully.', () {
+      setUp(() async {
+        final mockIdp = MockCognitoIdentityProviderClient(
+          getDevice: () async => mockDeviceResponse,
+          forgetDevice: () async {},
+        );
+        plugin.stateMachine.addInstance<CognitoIdentityProviderClient>(mockIdp);
+      });
+
+      test(
+          'This test should get the current device, where the current device id is equal to the local device id',
+          () async {
+        final secrets = await repo.get(username);
+        final currentDeviceKey = secrets?.deviceKey;
+        expect(currentDeviceKey, isNotNull);
+        final currentDevice = await plugin.fetchCurrentDevice();
+        expect(currentDeviceKey, currentDevice.id);
+      });
+
+      test(
+          'This test should throw a DeviceNotTrackedException when current device key is null',
+          () async {
+        await plugin.forgetDevice();
+        await expectLater(
+          plugin.fetchCurrentDevice,
+          throwsA(isA<DeviceNotTrackedException>()),
+        );
+      });
+    });
+
+    group('This test should have Cognito GetDevice throw a AWSHttpException',
+        () {
+      setUp(() async {
+        final mockIdp = MockCognitoIdentityProviderClient(
+          getDevice: () async => throw AWSHttpException(
+            AWSHttpRequest.get(Uri.parse('https://aws.amazon.com/cognito/')),
+          ),
+        );
+        plugin.stateMachine.addInstance<CognitoIdentityProviderClient>(mockIdp);
+      });
+
+      test('This test should have Cognito GetDevice throw a NetworkException',
+          () async {
+        await expectLater(
+          plugin.fetchCurrentDevice,
+          throwsA(isA<NetworkException>()),
+        );
+      });
+    });
+
+    tearDown(() async {
+      await plugin.close();
+    });
+  });
+}