C#-AutoFixture：如何使用ISpecimenBuilder创建多态对象

我对如何更好地编写代码有些不知所措.使用反射来获得Create< T>.在标本的上下文是可怕的.遗憾的是,不赞成使用CreateAnonymous …所以我想不出更好的方法.

IX是一个接口,标本构建器正在创建用于实施IX的具体类的随机实例以进行测试.

/// <summary>
/// A specimen builder that creates random X messages.
/// </summary>
public class XMessageBuilder : ISpecimenBuilder
{
    // for brevity assume this has types implementing IX
    private readonly Type[] types;
    private readonly Random random = new Random();

    // THERE MUST BE A BETTER WAY TO DO THIS?
    // CreateAnonymous is deprecated :-(
    public IX CreateSampleMessage(ISpecimenContext context)
    {
        var rm = this.types.ElementAt(this.random.Next(0, this.types.Length));
        var method = typeof(SpecimenFactory).GetMethod("Create", new[] { typeof(ISpecimenContext) });
        var generic = method.MakeGenericMethod(rm);
        var instance = generic.Invoke(null, new object[] { context });
        return (IX)instance;
    }

    public object Create(object request, ISpecimenContext context)
    {
        var parameter = request as ParameterInfo;
        if (parameter == null)
            return new NoSpecimen();

        if (parameter.ParameterType == typeof(IX))
            return this.CreateSampleMessage(context);

        if (parameter.ParameterType == typeof(IX[]))
        {
            var array = new IX[10];
            for (int index = 0; index < array.Length; index++)
                array[index] = this.CreateSampleMessage(context);
            return array;
        }

        return new NoSpecimen();
    }

解决方法:

这样的事情应该起作用：

public IX CreateSampleMessage(ISpecimenContext context)
{
    var rm = this.types.ElementAt(this.random.Next(0, this.types.Length));
    return (IX)context.Resolve(rm);
}

(不过,我没有尝试编译和运行repro,所以我可能在某个地方出错了.)

标签：autofixture,c
来源： https://codeday.me/bug/20191027/1947780.html