public async Task GetArticlesGroupsByDateAsync_ReturnCountOfArticlesGroupedByDate_WhenGetData() { // Arrange m_MockArticlesSourceService.Setup(service => service.GetDataAsync(SECTION)).ReturnsAsync(ARTICLE_SOURCES.ToList()); var articlesService = new ArticlesService(m_MockArticlesSourceService.Object); var expectedArticleGroups = ARTICLE_SOURCES.GroupBy(sourceArticle => sourceArticle.UpdatedDate.Date) .Select(group => (group.Key.ToString(DATE_FORMAT), group.Count())).ToList(); // Act var articleGroups = await articlesService.GetArticlesGroupsByDateAsync(SECTION, DATE_FORMAT); // Assert m_MockArticlesSourceService.Verify(service => service.GetDataAsync(SECTION), Times.Once); Assert.Equal(expectedArticleGroups, articleGroups); }