c# - 如何使用 NSubstitute 模拟 protected 方法

Question

public static void Mock(out IProgram prog, out IJson json)
{    
    prog = Substitute.For<IProgram>();
    IJson = Substitute.For<IJson>();

    prog.SaveProg(1, 1, 1, "Somthing", 1, DateTime.UtcNow,
                 (DateTime.UtcNow + TimeSpan.FromDays(10)), 
                 10, "someemail@email.com", DateTime.UtcNow, 1)
        .Returns(ObjectResult<int?>); 
}

调用 Returns(ObjectResult<int?>) 时出现错误因为ObjectResult是保护类。我该如何解决这个问题，以便能够从实际方法中调用我模拟的方法？

Answer 1

NSubstitute 会在您调用该方法后覆盖替代方法的行为，但它实际上并不关心您是如何调用该方法的。这允许您通过反射调用它。

下面是一个非常详细的例子:

public class SomeRepository
{
    public string ReadData() => ActuallyPerformDataReading();
    protected virtual string ActuallyPerformDataReading() => "some wrong data";
}

public class SomeClass
{
    SomeRepository _someRepository;
    public SomeClass(SomeRepository someRepository)
    {
        _someRepository = someRepository;
    }

    public string ReadSomething() => _someRepository.ReadData();
}


var repositorySub = Substitute.For<SomeRepository>();
repositorySub.GetType().GetMethod("ActuallyPerformDataReading", BindingFlags.NonPublic | BindingFlags.Instance)
    .Invoke(repositorySub, new object[] {}).Returns("some test data");
var sut = new SomeClass(repositorySub);

var result = sut.ReadSomething(); //"some test data"