feature: created the domain layer with test driven development (news …

…details feature)

lib/features/news_details/domain/entities/gpt_result_entity.dart

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+import 'package:equatable/equatable.dart';
+
+class GptResultEntity extends Equatable {
+  final String? id;
+  final String? object;
+  final int? created;
+  final String? model;
+  final List<ChoicesEntity>? choices;
+  final UsageEntity? usage;
+
+  const GptResultEntity(
+      {this.id,
+      this.object,
+      this.created,
+      this.model,
+      this.choices,
+      this.usage});
+
+  @override
+  List<Object?> get props => [id, object, created, model, choices, usage];
+}
+
+class ChoicesEntity extends Equatable {
+  final String? text;
+  final int? index;
+  final String? finishReason;
+
+  const ChoicesEntity({this.text, this.index, this.finishReason});
+
+  @override
+  List<Object?> get props => [text, index, finishReason];
+}
+
+class UsageEntity extends Equatable {
+  final int? promptTokens;
+  final int? completionTokens;
+  final int? totalTokens;
+
+  const UsageEntity(
+      {this.promptTokens, this.completionTokens, this.totalTokens});
+
+  @override
+  List<Object?> get props => [promptTokens, completionTokens, totalTokens];
+}

lib/features/news_details/domain/repositories/gpt_result_repository.dart

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+import 'package:dartz/dartz.dart';
+import 'package:news_app/core/error/failures.dart';
+import 'package:news_app/features/news_details/domain/entities/gpt_result_entity.dart';
+
+abstract class GptResultRepository {
+  Future<Either<Failure, GptResultEntity>> getGptResult(String articleContent);
+}

lib/features/news_details/domain/use_cases/get_gpt_result_for_an_article_content.dart

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+import 'package:dartz/dartz.dart';
+import 'package:news_app/core/error/failures.dart';
+import 'package:news_app/core/use_cases/use_case.dart';
+import 'package:news_app/features/news_details/domain/entities/gpt_result_entity.dart';
+import 'package:news_app/features/news_details/domain/repositories/gpt_result_repository.dart';
+
+class GetGptResultForAnArticleContent
+    implements UseCase<GptResultEntity, Params> {
+  final GptResultRepository repository;
+
+  GetGptResultForAnArticleContent(this.repository);
+
+  @override
+  Future<Either<Failure, GptResultEntity>> call(Params params) {
+    return repository.getGptResult(params.articleContent);
+  }
+}
+
+class Params {
+  final String articleContent;
+
+  const Params({required this.articleContent});
+}

test/features/news_details/domain/use_cases/get_gpt_result_for_an_article_content_test.dart

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+import 'package:dartz/dartz.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mockito/annotations.dart';
+import 'package:mockito/mockito.dart';
+import 'package:news_app/features/news_details/domain/entities/gpt_result_entity.dart';
+import 'package:news_app/features/news_details/domain/repositories/gpt_result_repository.dart';
+import 'package:news_app/features/news_details/domain/use_cases/get_gpt_result_for_an_article_content.dart';
+
+import '../../../../core/fixtures/gpt_api_test_data.dart';
+import 'get_gpt_result_for_an_article_content_test.mocks.dart';
+
+@GenerateNiceMocks([MockSpec<GptResultRepository>()])
+void main() {
+  late MockGptResultRepository mockGptResultRepository;
+  late GetGptResultForAnArticleContent useCase;
+
+  setUp(() {
+    mockGptResultRepository = MockGptResultRepository();
+    useCase = GetGptResultForAnArticleContent(mockGptResultRepository);
+  });
+
+  const testArticleContent = kTestArticleContent;
+  const testGptResultEntity = GptResultEntity(
+    id: "cmpl-844MC2OPs6EFL5kI1FVWcUITzyCJn",
+    object: "text_completion",
+    created: 1695980752,
+    model: "gpt-3.5-turbo-instruct",
+    choices: [
+      ChoicesEntity(
+        text:
+            "\n\nThe PlayStation Store currently has multiple promotional sales offering discounts on over 2,000 PS4",
+        index: 0,
+        finishReason: "length",
+      ),
+    ],
+    usage: UsageEntity(
+      promptTokens: 46,
+      completionTokens: 20,
+      totalTokens: 66,
+    ),
+  );
+
+  test("should get the gpt result for an article content", () async {
+    //arrange
+    when(mockGptResultRepository.getGptResult(any))
+        .thenAnswer((_) async => const Right(testGptResultEntity));
+    //act
+    final result = await useCase.call(
+      const Params(articleContent: testArticleContent),
+    );
+
+    //assert
+
+    // UseCase should simply return whatever was returned from the Repository
+    expect(result, const Right(testGptResultEntity));
+    // Verify that the method has been called on the Repository with the given parameter
+    verify(mockGptResultRepository.getGptResult(testArticleContent));
+    // Only the above method should be called and nothing more.
+    verifyNoMoreInteractions(mockGptResultRepository);
+  });
+}
+
+/*
+  test("should", () {
+    //arrange
+
+    //act
+
+    //assert
+  });
+*/

test/features/news_details/domain/use_cases/get_gpt_result_for_an_article_content_test.mocks.dart

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+// Mocks generated by Mockito 5.4.2 from annotations
+// in news_app/test/features/news_details/domain/use_cases/get_gpt_result_for_an_article_content_test.dart.
+// Do not manually edit this file.
+
+// ignore_for_file: no_leading_underscores_for_library_prefixes
+import 'dart:async' as _i4;
+
+import 'package:dartz/dartz.dart' as _i2;
+import 'package:mockito/mockito.dart' as _i1;
+import 'package:news_app/core/error/failures.dart' as _i5;
+import 'package:news_app/features/news_details/domain/entities/gpt_result_entity.dart'
+    as _i6;
+import 'package:news_app/features/news_details/domain/repositories/gpt_result_repository.dart'
+    as _i3;
+
+// ignore_for_file: type=lint
+// ignore_for_file: avoid_redundant_argument_values
+// ignore_for_file: avoid_setters_without_getters
+// ignore_for_file: comment_references
+// ignore_for_file: implementation_imports
+// ignore_for_file: invalid_use_of_visible_for_testing_member
+// ignore_for_file: prefer_const_constructors
+// ignore_for_file: unnecessary_parenthesis
+// ignore_for_file: camel_case_types
+// ignore_for_file: subtype_of_sealed_class
+
+class _FakeEither_0<L, R> extends _i1.SmartFake implements _i2.Either<L, R> {
+  _FakeEither_0(
+    Object parent,
+    Invocation parentInvocation,
+  ) : super(
+          parent,
+          parentInvocation,
+        );
+}
+
+/// A class which mocks [GptResultRepository].
+///
+/// See the documentation for Mockito's code generation for more information.
+class MockGptResultRepository extends _i1.Mock
+    implements _i3.GptResultRepository {
+  @override
+  _i4.Future<_i2.Either<_i5.Failure, _i6.GptResultEntity>> getGptResult(
+          String? articleContent) =>
+      (super.noSuchMethod(
+        Invocation.method(
+          #getGptResult,
+          [articleContent],
+        ),
+        returnValue:
+            _i4.Future<_i2.Either<_i5.Failure, _i6.GptResultEntity>>.value(
+                _FakeEither_0<_i5.Failure, _i6.GptResultEntity>(
+          this,
+          Invocation.method(
+            #getGptResult,
+            [articleContent],
+          ),
+        )),
+        returnValueForMissingStub:
+            _i4.Future<_i2.Either<_i5.Failure, _i6.GptResultEntity>>.value(
+                _FakeEither_0<_i5.Failure, _i6.GptResultEntity>(
+          this,
+          Invocation.method(
+            #getGptResult,
+            [articleContent],
+          ),
+        )),
+      ) as _i4.Future<_i2.Either<_i5.Failure, _i6.GptResultEntity>>);
+}