public void ReturnAllArticles() { // Arrange var dbContextMock = new Mock <ApplicationDbContext>(); var article = new Article(); var articles = new List <Article>() { article }; var articlesSetMock = new Mock <DbSet <Article> >(); articlesSetMock.SetupData(articles); dbContextMock.Setup(m => m.Articles).Returns(articlesSetMock.Object); var service = new ArticleServices(dbContextMock.Object); // Act var result = service.ListAllArticles().ToList(); // Assert CollectionAssert.AreEqual(articles, result); }