public async Task GetSellers_Should_Return_List_Of_Sellers() { // Arrange await _dbContext.Database.EnsureDeletedAsync(); var listOfSellers = new List <tblSellers>(); listOfSellers.Add(new tblSellersBuilder().WithId(1).WithName("Amazon").WithUrl("https://www.amazon.co.uk").Build()); listOfSellers.Add(new tblSellersBuilder().WithId(2).WithName("Ebay").WithUrl("https://www.ebay.co.uk").Build()); listOfSellers.Add(new tblSellersBuilder().WithId(3).WithName("Currys PC World").WithUrl("https://www.currys.co.uk").Build()); _dbContext.tblSellers.AddRange(listOfSellers); await _dbContext.SaveChangesAsync(); // Act var task = _userSettingsService.GetSellers(); var result = task.Result; Assert.IsAssignableFrom <IEnumerable <Seller> >(result); Assert.Equal(3, result.Count()); }