C＃-Moq-System.Text.Json自定义JsonConverter-如何模拟一个接受引用结构参数的方法？

如何解决C＃-Moq-System.Text.Json自定义JsonConverter-如何模拟一个接受引用结构参数的方法？

我是新手，试图学习使用xUnit和Moq进行测试。

我正在为自定义Json.Text.Json.Serialization.JsonConverter编写测试，并且遇到了绊脚石。

Read的抽象JsonConverter方法接受引用结构Utf8JsonReader。在我的自定义转换器类中将其覆盖。

我的自定义转换器类创建了一个具有accept方法的解析模型（请参见下面的IVisitorElement）。这会将反序列化责任移交给访问者实例（请参见下面的IVisitor），以将json反序列化为解析模型。

自定义转换器类

using System;
using System.Text.Json;
using System.Text.Json.Serialization;

using Microsoft.Extensions.Logging;

using WebApp.Data.Serializers.Converters.Visitors;

namespace WebApp.Data.Serializers.Converters
{
    public sealed class MotionDetectionConverter : JsonConverter<MotionDetection>
    {
        private readonly ILogger _log;
        private readonly IVisitorElement<MotionDetection> _parseModel;
        private IVisitor _visitor;
        
        public MotionDetectionConverter(
            IVisitor visitor,IVisitorElement<MotionDetection> parseModel,ILogger<MotionDetectionConverter> logger)
        {
            _log = logger ?? throw new ArgumentNullException(nameof(logger));
            _visitor = visitor ?? throw new ArgumentNullException(nameof(visitor));
            _parseModel = parseModel ?? throw new ArgumentNullException(nameof(parseModel));
        }

        public override MotionDetection Read(ref Utf8JsonReader reader,Type typetoConvert,JsonSerializerOptions options)
        {
            _parseModel.accept(_visitor,ref reader,options);

            _log.Loginformation("\n{0}\n",_parseModel);

            return _parseModel.ToModel();
        }

        public override void Write(Utf8JsonWriter writer,MotionDetection motionDetection,JsonSerializerOptions options) =>
                throw new NotImplementedException("Serialization of MotionDetection objects is not implemented");
    }
}

VisitorElement界面

    public interface IVisitorElement<ModelType>
    {
        void accept(IVisitor visitor,ref Utf8JsonReader reader,JsonSerializerOptions options);
        ModelType ToModel();
    }

访问者界面

    public interface IVisitor {
        void DeserializeMotionDetection(ParsedMotionDetection target,JsonSerializerOptions options);
        void DeserializeMotionInfo(ParsedMotionInfo target,JsonSerializerOptions options);
        void DeserializeMotionLocation(ParsedLocation target,JsonSerializerOptions options)
    }

到目前为止的测试...

        [Fact(Skip="How to mock a method that accepts a ref struct parameter?")]
        public void MotionDetectionConverter_Deserialize_Unittest()
        {
            MotionDetection expected = CreateMotionDetection();
            Utf8JsonReader reader = CreateUtf8JsonReader();

            var visitorMock = new Mock<IVisitor>();
            var parsedDetectionModelMock = new Mock<IVisitorElement<MotionDetection>>();
            var parsedInfoModelMock = new Mock<IVisitorElement<MotionInfo>>();
           
            var converter = new MotionDetectionConverter(visitorMock.Object,parsedDetectionModelMock.Object,new NullLogger<MotionDetectionConverter>());
            var infoConverter = new MotionInfoConverter(visitorMock.Object,parsedInfoModelMock.Object,new NullLogger<MotionInfoConverter>());
            
            JsonSerializerOptions serializeOptions = new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase };
            serializeOptions.Converters.Add(converter);
            serializeOptions.Converters.Add(infoConverter);

            // The Read method of my custom converter class calls the accept 
            // method of a Visitor class,passing the ref struct Utf8JsonReader 
            // and JsonSerializationoptions.
            // I want to use a mock to check that this call is made to the 
            // accept method of the Visitor class.......
            // but this raise a compile error detailed below.

            parsedDetectionModelMock.Setup(x => x.accept(visitorMock,serializeOptions));
        }

当我尝试模拟对Visitor类的accept方法的调用时：

parsedDetectionModelMock.Setup(x => x.accept(visitorMock,serializeOptions));

我收到以下错误：

Cannot use ref local 'reader' inside an anonymous method,lambda expression or query method csharp CS8175

如何使用Moq来测试接受ref结构作为参数的方法？

看看最近的最低起订量issue，这似乎是已知的限制。

此question回答了如何测试使用ref参数调用的方法。但是，它没有建议解决方案的解决方案。由于Utf8JsonReader是一个引用结构，因此不能用于以下泛型中：

/// fails with cannot use Utf8JsonReader as a type parameter
parsedDetectionModelMock.Setup(x => x.accept(visitorMock.Object,ref It.Ref<Utf8JsonReader>.IsAny,serializeOptions));

开发人员如何测试类似方案？

有没有其他能够管理此功能的模拟框架？