public async Task Given_A_UserId_Adn_DeckId_Should_Invoke_DeleteDeckByIdAndUserId_Once() { // Arrange const int expected = 1; _deckRepository.Search(Arg.Any <DeckSearchCriteria>()).Returns(new DeckSearchResult()); // Act var userId = Guid.NewGuid().ToString(); const int deckId = 234242; await _sut.DeleteDeckByIdAndUserId(userId, deckId); // Assert await _deckRepository.Received(expected).DeleteDeckByIdAndUserId(userId, deckId); }