public async Task CanAddOrUpdateItems() { var item = new InMemoryBar1(); item.Id = 1; item.Name = "aa"; item.Category = "bb"; await _inMemoryRepository.AddOrUpdateAsync(item, null); var itemAgain = new InMemoryBar1(); itemAgain.Id = 1; itemAgain.Name = "cc"; itemAgain.Category = "dd"; await _inMemoryRepository.AddOrUpdateAsync(itemAgain, null); var updatedItem = await GetById(1); updatedItem.Name.ShouldBe("cc"); updatedItem.Category.ShouldBe("dd"); }