Updated Either implementation

packages/clean_framework/example/test/features/country/external_interface/country_gateway_test.dart

@@ -16,7 +16,7 @@ void main() {
       final gateway = countryGatewayProvider.getGateway(providersContext);
 
       gateway.transport = (request) async {
-        return Right(
+        return Either.right(
           GraphQLSuccessResponse(
             data: {
               'countries': [

packages/clean_framework/example/test/features/country/presentation/country_ui_test.dart

@@ -20,7 +20,7 @@ void main() {
   final gateway = countryGatewayProvider.getGateway(providersContext);
 
   gateway.transport = (request) async {
-    return Right(
+    return Either.right(
       GraphQLSuccessResponse(
         data: {
           'countries': request.continentCode == 'NA'

packages/clean_framework/example/test/features/last_login/domain/last_login_usecase_test.dart

@@ -12,9 +12,7 @@ void main() {
     // Subscription shortcut to mock a successful response from a Gateway
 
     useCase.subscribe<LastLoginDateOutput, LastLoginDateInput>(
-      (_) => Right<FailureInput, LastLoginDateInput>(
-        LastLoginDateInput(currentDate),
-      ),
+      (_) => Either.right(LastLoginDateInput(currentDate)),
     );
 
     var output = useCase.getOutput<LastLoginUIOutput>();
@@ -39,7 +37,7 @@ void main() {
     useCase.subscribe<LastLoginDateOutput, LastLoginDateInput>(
       (output) {
         expect(output, LastLoginDateOutput());
-        return Left<FailureInput, LastLoginDateInput>(FailureInput());
+        return Either.left(FailureInput());
       },
     );
 

packages/clean_framework/example/test/features/last_login/external_interface/last_login_date_gateway_test.dart

@@ -1,10 +1,9 @@
+import 'package:clean_framework/clean_framework.dart';
 import 'package:clean_framework/clean_framework_providers.dart';
-import 'package:clean_framework/src/app_providers_container.dart';
 import 'package:clean_framework_example/features/last_login/domain/last_login_use_case.dart';
 import 'package:clean_framework_example/features/last_login/external_interface/last_login_date_gateway.dart';
 import 'package:clean_framework_firestore/clean_framework_firestore.dart';
 import 'package:clean_framework_test/clean_framework_test.dart';
-import 'package:either_dart/either.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 final context = ProvidersContext();
@@ -16,7 +15,7 @@ void main() {
     var gateway = LastLoginDateGateway(context: context, provider: provider);
 
     gateway.transport = (request) async =>
-        Right(FirebaseSuccessResponse({'date': '2000-01-01'}));
+        Either.right(FirebaseSuccessResponse({'date': '2000-01-01'}));
 
     final testRequest = LastLoginDateRequest();
     expect(testRequest.id, '12345');
@@ -32,7 +31,8 @@ void main() {
     final provider = UseCaseProvider((_) => useCase);
     var gateway = LastLoginDateGateway(context: context, provider: provider);
 
-    gateway.transport = (request) async => Left(UnknownFailureResponse());
+    gateway.transport =
+        (request) async => Either.left(UnknownFailureResponse());
 
     await useCase.doFakeRequest(LastLoginDateOutput());
 

packages/clean_framework/example/test/features/random_cat/domain/random_cat_use_case_test.dart

@@ -19,7 +19,7 @@ void main() {
       final gateway = randomCatGatewayProvider.getGateway(providersContext);
 
       gateway.transport = (request) async {
-        return Right(RestSuccessResponse(
+        return Either.right(RestSuccessResponse(
           data: {
             'id': 420,
             'webpurl':
@@ -54,7 +54,7 @@ void main() {
       final gateway = randomCatGatewayProvider.getGateway(providersContext);
 
       gateway.transport = (request) async {
-        return Left(UnknownFailureResponse());
+        return Either.left(UnknownFailureResponse());
       };
 
       expect(

packages/clean_framework/lib/clean_framework.dart

@@ -10,6 +10,6 @@ export 'package:clean_framework/src/logger.dart';
 export 'package:clean_framework/src/open_feature/open_feature.dart';
 export 'package:clean_framework/src/utilities/clean_framework_observer.dart';
 export 'package:clean_framework/src/utilities/deserializer.dart';
+export 'package:clean_framework/src/utilities/either.dart';
 export 'package:clean_framework/src/utilities/network_logger.dart';
 export 'package:clean_framework/src/widgets/widgets.dart';
-export 'package:either_dart/either.dart';

packages/clean_framework/lib/src/providers/external_interface.dart

@@ -2,7 +2,7 @@ import 'dart:async';
 
 import 'package:clean_framework/src/providers/gateway.dart';
 import 'package:clean_framework/src/utilities/clean_framework_observer.dart';
-import 'package:either_dart/either.dart';
+import 'package:clean_framework/src/utilities/either.dart';
 
 abstract class ExternalInterface<R extends Request, S extends SuccessResponse> {
   ExternalInterface(List<GatewayConnection<Gateway>> gatewayConnections) {
@@ -87,10 +87,10 @@ class _RequestCompleter<R extends Request, S extends SuccessResponse> {
 
   bool get isCompleted => _completer.isCompleted;
 
-  void complete(S success) => _completer.complete(Right(success));
+  void complete(S success) => _completer.complete(Either.right(success));
 
   void completeFailure(FailureResponse failure) {
-    _completer.complete(Left(failure));
+    _completer.complete(Either.left(failure));
   }
 }
 

packages/clean_framework/lib/src/providers/gateway.dart

@@ -1,7 +1,7 @@
 import 'package:clean_framework/clean_framework_providers.dart';
 import 'package:clean_framework/src/app_providers_container.dart';
 import 'package:clean_framework/src/utilities/clean_framework_observer.dart';
-import 'package:either_dart/either.dart';
+import 'package:clean_framework/src/utilities/either.dart';
 import 'package:equatable/equatable.dart';
 import 'package:meta/meta.dart';
 
@@ -34,8 +34,8 @@ abstract class Gateway<O extends Output, R extends Request,
   Future<Either<FailureInput, S>> _processRequest(R request) async {
     final either = await transport(request);
     return either.fold(
-      (failureResponse) => Left(_onFailure(failureResponse)),
-      (response) => Right(onSuccess(response)),
+      (failureResponse) => Either.left(_onFailure(failureResponse)),
+      (response) => Either.right(onSuccess(response)),
     );
   }
 
@@ -55,7 +55,7 @@ abstract class BridgeGateway<SUBSCRIBER_OUTPUT extends Output,
         _publisherUseCase = publisherUseCase {
     _subscriberUseCase.subscribe<SUBSCRIBER_OUTPUT, SUBSCRIBER_INPUT>(
       (output) {
-        return Right<FailureInput, SUBSCRIBER_INPUT>(
+        return Either<FailureInput, SUBSCRIBER_INPUT>.right(
           onResponse(
             _publisherUseCase.getOutput<PUBLISHER_OUTPUT>(),
           ),

packages/clean_framework/lib/src/providers/use_case/helpers/request_subscription_map.dart

@@ -2,7 +2,7 @@ import 'dart:async';
 
 import 'package:clean_framework/src/providers/use_case/helpers/input.dart';
 import 'package:clean_framework/src/providers/use_case/helpers/output.dart';
-import 'package:either_dart/either.dart';
+import 'package:clean_framework/src/utilities/either.dart';
 
 typedef RequestSubscriptionMap<I extends Input>
     = Map<Type, RequestSubscription<I>>;
@@ -27,7 +27,7 @@ extension RequestSubscriptionMapExtension<I extends Input>
     final subscription = this[O];
 
     if (subscription == null) {
-      return Left<NoSubscriptionFailureInput, S>(
+      return Either<NoSubscriptionFailureInput, S>.left(
         NoSubscriptionFailureInput<O>(),
       );
     }

packages/clean_framework/lib/src/utilities/either.dart

@@ -0,0 +1,99 @@
+import 'package:meta/meta.dart';
+
+@Deprecated('Use Either.left')
+typedef Left<L, R> = _Left<L, R>;
+
+@Deprecated('Use Either.right')
+typedef Right<L, R> = _Right<L, R>;
+
+/// Signature for a function that maps
+/// either the left or the right side of this disjunction.
+typedef EitherMapper<T, E> = T Function(E);
+
+@sealed
+@immutable
+
+/// [Either] represents a value of two possible types.
+/// An Either is either an [Either.left] or an [Either.right].
+abstract class Either<L, R> {
+  /// Constructs an [Either].
+  const Either();
+
+  /// The Left version of an [Either].
+  const factory Either.left(L value) = _Left<L, R>;
+
+  /// The Right version of an [Either].
+  const factory Either.right(R value) = _Right<L, R>;
+
+  /// Returns whether this [Either] is an [Either.left].
+  bool get isLeft => this is _Left<L, R>;
+
+  /// Returns whether this [Either] is an [Either.right].
+  bool get isRight => this is _Right<L, R>;
+
+  /// Gets the right value if this is an [Either.left]
+  /// or throws if this is a [Either.right].
+  L get left {
+    return fold<L>((left) => left, _noSuchElementException);
+  }
+
+  /// Gets the right value if this is an [Either.right]
+  /// or throws if this is an [Either.left].
+  R get right {
+    return fold<R>(_noSuchElementException, (right) => right);
+  }
+
+  /// Folds either the left or the right side of this disjunction.
+  T fold<T>(EitherMapper<T, L> leftMapper, EitherMapper<T, R> rightMapper);
+
+  Never _noSuchElementException(value) {
+    throw NoSuchElementException(
+      'You should check ${isLeft ? 'isLeft' : 'isRight'} before calling.',
+    );
+  }
+}
+
+class _Left<L, R> extends Either<L, R> {
+  const _Left(this.value);
+
+  /// The Left value of an [Either].
+  final L value;
+
+  @override
+  T fold<T>(EitherMapper<T, L> leftMapper, EitherMapper<T, R> rightMapper) {
+    return leftMapper(value);
+  }
+
+  @override
+  bool operator ==(Object other) => other is _Left && value == other.value;
+
+  @override
+  int get hashCode => value.hashCode;
+}
+
+class _Right<L, R> extends Either<L, R> {
+  const _Right(this.value);
+
+  /// The Right value of an [Either].
+  final R value;
+
+  @override
+  T fold<T>(EitherMapper<T, L> leftMapper, EitherMapper<T, R> rightMapper) {
+    return rightMapper(value);
+  }
+
+  @override
+  bool operator ==(Object other) => other is _Right && value == other.value;
+
+  @override
+  int get hashCode => value.hashCode;
+}
+
+/// [Exception] that indicates the element being requested does not exist.
+class NoSuchElementException implements Exception {
+  /// Creates a [NoSuchElementException] with an optional error [message].
+  const NoSuchElementException([this.message = '']);
+
+  /// The message describing the exception.
+  final String message;
+}

packages/clean_framework/pubspec.yaml

@@ -9,13 +9,12 @@ environment:
   flutter: '>=3.0.0'
 
 dependencies:
-  either_dart: ^0.2.0
   equatable: ^2.0.5
   flutter:
     sdk: flutter
-  flutter_riverpod: ^2.1.0
+  flutter_riverpod: ^2.1.3
   meta: '>=1.8.0 <1.9.0'
-  riverpod: ^2.1.1
+  riverpod: ^2.1.3
 
 dev_dependencies:
   clean_framework_test: ^0.1.0

packages/clean_framework/test/providers/gateway_integration_test.dart

@@ -1,6 +1,5 @@
+import 'package:clean_framework/clean_framework.dart';
 import 'package:clean_framework/clean_framework_providers.dart';
-import 'package:clean_framework/src/app_providers_container.dart';
-import 'package:either_dart/either.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 final context = ProvidersContext();
@@ -11,9 +10,7 @@ void main() {
       (_) => TestUseCase(TestEntity(foo: 'bar')),
     );
     TestDirectGateway(provider).transport = (request) async {
-      return const Right<FailureResponse, TestResponse>(
-        TestResponse('success'),
-      );
+      return const Either.right(TestResponse('success'));
     };
 
     final useCase = provider.getUseCaseFromContext(context);
@@ -29,7 +26,7 @@ void main() {
       (_) => TestUseCase(TestEntity(foo: 'bar')),
     );
     TestDirectGateway(provider).transport = (request) async {
-      return Left<FailureResponse, TestResponse>(UnknownFailureResponse());
+      return Either.left(UnknownFailureResponse());
     };
 
     final useCase = provider.getUseCaseFromContext(context);
@@ -46,9 +43,7 @@ void main() {
     );
     final gateway = TestYieldGateway(provider)
       ..transport = (request) async {
-        return const Right<FailureResponse, TestResponse>(
-          TestResponse('success'),
-        );
+        return const Either.right(TestResponse('success'));
       };
 
     final useCase = provider.getUseCaseFromContext(context);

packages/clean_framework/test/providers/gateway_unit_test.dart

@@ -1,7 +1,6 @@
+import 'package:clean_framework/clean_framework.dart';
 import 'package:clean_framework/clean_framework_providers.dart';
-import 'package:clean_framework/src/app_providers_container.dart';
 import 'package:clean_framework_test/clean_framework_test.dart';
-import 'package:either_dart/either.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 final context = ProvidersContext();
@@ -11,7 +10,7 @@ void main() {
     final useCase = UseCaseFake();
     final provider = UseCaseProvider((_) => useCase);
     TestDirectGateway(provider).transport = (request) async {
-      return const Right(TestResponse('success'));
+      return const Either.right(TestResponse('success'));
     };
 
     await useCase.doFakeRequest(TestDirectOutput('123'));
@@ -23,7 +22,7 @@ void main() {
     final useCase = UseCaseFake();
     final provider = UseCaseProvider((_) => useCase);
     TestDirectGateway(provider).transport = (request) async {
-      return Left(UnknownFailureResponse());
+      return Either.left(UnknownFailureResponse());
     };
 
     await useCase.doFakeRequest(TestDirectOutput('123'));
@@ -36,7 +35,7 @@ void main() {
     final provider = UseCaseProvider((_) => useCase);
     final gateway = TestYieldGateway(provider)
       ..transport = (request) async {
-        return const Right(TestResponse('success'));
+        return const Either.right(TestResponse('success'));
       };
 
     await useCase.doFakeRequest(TestSubscriptionOutput('123'));
@@ -52,7 +51,7 @@ void main() {
     final useCase = UseCaseFake();
     final provider = UseCaseProvider((_) => useCase);
     TestYieldGateway(provider).transport = (request) async {
-      return Left(UnknownFailureResponse());
+      return Either.left(UnknownFailureResponse());
     };
 
     await useCase.doFakeRequest(TestSubscriptionOutput('123'));

packages/clean_framework/test/providers/use_case_unit_test.dart

@@ -1,5 +1,5 @@
+import 'package:clean_framework/clean_framework.dart';
 import 'package:clean_framework/clean_framework_providers.dart';
-import 'package:either_dart/either.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
@@ -24,12 +24,12 @@ void main() {
     expect(SuccessInput() == successInput, isFalse);
 
     useCase.subscribe<TestDirectOutput, TestSuccessInput>((output) {
-      return Right(successInput);
+      return Either.right(successInput);
     });
 
     expect(
       () => useCase.subscribe<TestDirectOutput, TestSuccessInput>((_) {
-        return Right(successInput);
+        return Either.right(successInput);
       }),
       throwsStateError,
     );
@@ -44,7 +44,7 @@ void main() {
   test('UseCase subscription with delayed response on input filter', () async {
     final useCase = TestUseCase(TestEntity(foo: ''))
       ..subscribe<TestSubscriptionOutput, SuccessInput>(
-        (output) => Right(SuccessInput()),
+        (output) => Either.right(SuccessInput()),
       );
 
     await useCase.fetchDataEventually();