使用Moq模擬要測試的對象的依賴關系時出現類型錯誤

Question

我有一個驗證類，我正在嘗試測試FluentQuestionAnswerValidator ，但是此類具有依賴項IQuestionAnswerRepository ，必須將其通過構造函數傳遞才能實例化驗證器類。

為了嘗試實例化該類，我使用Moq來模擬存儲庫，然后可以將其傳遞給驗證器。

但是，當我嘗試在實例化實例庫時將模擬的存儲庫傳遞到驗證器時，出現類型錯誤：

Error   CS1503  Argument 2: cannot convert from 
'Moq.Mock<IQuestionAnswerRepository>' to 'IQuestionAnswerRepository'    

如何更改已有的代碼，以使其接受模擬的存儲庫作為其依賴項？

class QuestionAnswerValidationTest
    {
        private QuestionAnswer _qaTest;
        private FluentQuestionAnswerValidator _validator;
        private Mock<IQuestionAnswerRepository> mockRepo;

        [SetUp]
        public void Setup()
        {
            _qaTest = new QuestionAnswer()
            {
                Id = 2,
                Type = "Number",
                Required = true,
                QuestionSection = 1,
            };

            QuestionAnswer qa = new QuestionAnswer()
            {
                Id = 1,
                Type = "String",
                Required = true,
                QuestionSection = 1,
                Answer = "Yes",
                ConditionalQuestionId = null,
                ConditionalQuestionAnswered = null
            };

            Dictionary<int, QuestionAnswer> questionMap = new Dictionary<int, QuestionAnswer>();
            questionMap.Add(qa.Id, qa);

            mockRepo = new Mock<IQuestionAnswerRepository>(MockBehavior.Strict);
            mockRepo.Setup(p => p.QuestionMap).Returns(questionMap);
        }

        [Test]
        public void Validate_AnswerDoesNotMatchQuestionType_ProducesValidationError()
        {
            _qaTest.Answer = "string";

            _validator = new FluentQuestionAnswerValidator(_qaTest, mockRepo);
        }
    }

Answer 1

您的FluentQuestionAnswerValidator顯然希望使用IQuestionAnswerRepository實例，而不是Mock<IQuestionAnswerRepository>實例。 由於這兩者之間沒有隱式轉換，因此會出現錯誤。

因此，您實際上想要提供的不是模擬本身，而是由框架創建的實例 。 所以改用這個：

_validator = new FluentQuestionAnswerValidator(_qaTest, mockRepo.Object);