Create unit test helper_test.dart

Author: CoderJava

test/core/util/helper_test.dart

@@ -0,0 +1,39 @@
+import 'package:flutter_news_app/core/util/enum/top_headline_news_category.dart';
+import 'package:flutter_news_app/core/util/helper.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  final helper = Helper();
+
+  test(
+    'Should return string of TopHeadlineNewsCategory',
+    () async {
+      // arrange
+      const business = TopHeadlineNewsCategory.business;
+      const entertainment = TopHeadlineNewsCategory.entertainment;
+      const general = TopHeadlineNewsCategory.general;
+      const health = TopHeadlineNewsCategory.health;
+      const science = TopHeadlineNewsCategory.science;
+      const sports = TopHeadlineNewsCategory.sports;
+      const technology = TopHeadlineNewsCategory.technology;
+
+      // act
+      final resultBusiness = helper.getStringTopHeadlineNewsCategory(business);
+      final resultEntertainment = helper.getStringTopHeadlineNewsCategory(entertainment);
+      final resultGeneral = helper.getStringTopHeadlineNewsCategory(general);
+      final resultHealth = helper.getStringTopHeadlineNewsCategory(health);
+      final resultScience = helper.getStringTopHeadlineNewsCategory(science);
+      final resultSports = helper.getStringTopHeadlineNewsCategory(sports);
+      final resultTechnology = helper.getStringTopHeadlineNewsCategory(technology);
+
+      // assert
+      expect(resultBusiness, 'business');
+      expect(resultEntertainment, 'entertainment');
+      expect(resultGeneral, 'general');
+      expect(resultHealth, 'health');
+      expect(resultScience, 'science');
+      expect(resultSports, 'sports');
+      expect(resultTechnology, 'technology');
+    },
+  );
+}