fix: repository methods

Author: iamc1oud

lib/core/error/exception.dart

@@ -0,0 +1,3 @@
+class ServerException implements Exception {}
+
+class CacheException implements Exception {}

lib/core/error/failures.dart

@@ -3,3 +3,15 @@ import 'package:equatable/equatable.dart';
 abstract class Failure extends Equatable {
   Failure([List properites = const <dynamic>[]]) : super();
 }
+
+class ServerFailure extends Failure {
+  @override
+  // TODO: implement props
+  List<Object> get props => throw UnimplementedError();
+}
+
+class CacheFailure extends Failure {
+  @override
+  // TODO: implement props
+  List<Object> get props => throw UnimplementedError();
+}

lib/core/platform/network_info.dart

@@ -0,0 +1,3 @@
+abstract class NetworkInfo {
+  Future<bool> get isConnected;
+}

lib/features/number_trivia/data/datasources/number_trivia_local_data_source.dart

@@ -0,0 +1,11 @@
+import 'package:tdd_number_trivia/features/number_trivia/data/models/number_trivia_model.dart';
+
+abstract class NumberTriviaLocalDataSource {
+  /// Gets the cached [NumberTriviaModel] which was gotten the last time
+  /// the user had an internet connection.
+  ///
+  /// Throws [NoLocalDataException] if no cached data is present.
+  Future<NumberTriviaModel> etLastNumberTrivia();
+
+  Future<void> cacheNumberTrivia(NumberTriviaModel triviaToCache);
+}

lib/features/number_trivia/data/datasources/number_trivia_remote_data_source.dart

@@ -0,0 +1,13 @@
+import 'package:tdd_number_trivia/features/number_trivia/data/models/number_trivia_model.dart';
+
+abstract class NumberTriviaRemoteDataSource {
+  /// Calls the http://numbersapi.com/{number} endpoint.
+  ///
+  /// Throws a [ServerException] for all error codes.
+  Future<NumberTriviaModel> getConcreteNumberTrivia(int number);
+
+  /// Calls the http://numbersapi.com/random endpoint.
+  ///
+  /// Throws a [ServerException] for all error codes.
+  Future<NumberTriviaModel> getRandomNumberTrivia();
+}

lib/features/number_trivia/data/repositories/number_tirivia_repository_impl.dart

@@ -0,0 +1,30 @@
+import 'package:flutter/foundation.dart';
+import 'package:tdd_number_trivia/core/platform/network_info.dart';
+import 'package:tdd_number_trivia/features/number_trivia/data/datasources/number_trivia_local_data_source.dart';
+import 'package:tdd_number_trivia/features/number_trivia/data/datasources/number_trivia_remote_data_source.dart';
+import 'package:tdd_number_trivia/features/number_trivia/domain/entities/number_trivia.dart';
+import 'package:tdd_number_trivia/core/error/failures.dart';
+import 'package:dartz/dartz.dart';
+import 'package:tdd_number_trivia/features/number_trivia/domain/repositories/number_trivia_repository.dart';
+
+class NumberTriviaRepositoryImpl implements NumberTriviaRepository {
+  final NumberTriviaRemoteDataSource remoteDataSource;
+  final NumberTriviaLocalDataSource localDataSource;
+  final NetworkInfo networkInfo;
+
+  NumberTriviaRepositoryImpl(
+      {@required this.remoteDataSource,
+      @required this.localDataSource,
+      @required this.networkInfo});
+
+  @override
+  Future<Either<Failure, NumberTrivia>> getConcreteNumberTrivia({int number}) {
+    networkInfo.isConnected;
+    return null;
+  }
+
+  @override
+  Future<Either<Failure, NumberTrivia>> getRandomNumberTrivia() {
+    return null;
+  }
+}

test/features/number_trivia/data/repository/number_trivia_repository_impl_test.dart

@@ -0,0 +1,65 @@
+import 'package:mockito/mockito.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:tdd_number_trivia/core/platform/network_info.dart';
+import 'package:tdd_number_trivia/features/number_trivia/data/datasources/number_trivia_local_data_source.dart';
+import 'package:tdd_number_trivia/features/number_trivia/data/datasources/number_trivia_remote_data_source.dart';
+import 'package:tdd_number_trivia/features/number_trivia/data/models/number_trivia_model.dart';
+import 'package:tdd_number_trivia/features/number_trivia/data/repositories/number_tirivia_repository_impl.dart';
+
+class MockRemoteDataSource extends Mock
+    implements NumberTriviaRemoteDataSource {}
+
+class MockLocalDataSource extends Mock implements NumberTriviaLocalDataSource {}
+
+class MockNetworkInfo extends Mock implements NetworkInfo {}
+
+void main() {
+  NumberTriviaRepositoryImpl numberTriviaRepositoryImpl;
+  MockRemoteDataSource mockRemoteDataSource;
+  MockLocalDataSource mockLocalDataSource;
+  MockNetworkInfo mockNetworkInfo;
+
+  setUp(() {
+    mockLocalDataSource = MockLocalDataSource();
+    mockRemoteDataSource = MockRemoteDataSource();
+    mockNetworkInfo = MockNetworkInfo();
+    numberTriviaRepositoryImpl = NumberTriviaRepositoryImpl(
+        remoteDataSource: mockRemoteDataSource,
+        localDataSource: mockLocalDataSource,
+        networkInfo: mockNetworkInfo);
+  });
+
+  group("getConcreteNumberTrivia", () {
+    final tNumber = 1;
+    final tNumberTriviaModel =
+        NumberTriviaModel(number: tNumber, text: "Hello");
+    test("should check if device is online", () async {
+      when(mockNetworkInfo.isConnected).thenAnswer((_) async => true);
+
+      numberTriviaRepositoryImpl.getConcreteNumberTrivia(number: tNumber);
+
+      verify(mockNetworkInfo.isConnected);
+    });
+
+    group("device is online", () {
+      setUp(() {
+        when(mockNetworkInfo.isConnected)
+            .thenAnswer((realInvocation) async => true);
+      });
+
+      test(
+          "should return remote data when the call to remote data source is successful",
+          () async {
+        when(mockRemoteDataSource.getConcreteNumberTrivia(any))
+            .thenAnswer((realInvocation) async => tNumberTriviaModel);
+      });
+    });
+
+    group("device is offline", () {
+      setUp(() {
+        when(mockNetworkInfo.isConnected)
+            .thenAnswer((realInvocation) async => false);
+      });
+    });
+  });
+}