public async void Post_Title_Cannot_Be_Null_Or_Empty(string title, int numberOfErrors, string[] expectedMessages) { // Arrange: a blog post with an invalid title var blogPost = new BlogPost { Title = title, UserId = Actor.AUTHOR_ID }; // Act: validate var result = await _validator.ValidateAsync(blogPost); // Assert: number of errors and messages Assert.Equal(numberOfErrors, result.Errors.Count); Assert.Equal(expectedMessages[0], result.Errors[0].ErrorMessage); if (numberOfErrors > 1) { Assert.Equal(expectedMessages[1], result.Errors[1].ErrorMessage); } }