如何创建省略各种类型的自动属性的自定义？

Question

我正在尝试创建一个自定义,允许我指定不应填充不在某个名称空间中的类型的属性.

基本上,我试图改变这个:

fixture.Customize<Window>(c => c.OmitAutoProperties());
fixture.Customize<ContentControl>(c => c.OmitAutoProperties());
fixture.Customize<TextBlock>(c => c.OmitAutoProperties());
// Many many more...

对此:

fixture.Customize(t => !t.Namespace.StartsWith("MyProject"),
                  c => c.OmitAutoProperties());

怎么做到这一点？

我实际上只关心结果,而不是这里显示的虚构API,所以实现我自己ISpecimenBuilder或ICustomization不是问题.

Answer 1

最简单的方法可能是通过自定义样本生成器：

public class OmitPropertyForTypeInNamespace : ISpecimenBuilder
{
    private readonly string ns;

    public OmitPropertyForTypeInNamespace(string ns)
    {
        this.ns = ns;
    }

    public object Create(object request, ISpecimenContext context)
    {
        if (IsProperty(request) &&
            IsDeclaringTypeInNamespace((PropertyInfo)request))
        {
            return new OmitSpecimen();
        }

        return new NoSpecimen(request);
    }

    private bool IsProperty(object request)
    {
        return request is PropertyInfo;
    }

    private bool IsDeclaringTypeInNamespace(PropertyInfo property)
    {
        var declaringType = property.DeclaringType;
        return declaringType.Namespace.Equals(
            this.ns,
            StringComparison.OrdinalIgnoreCase);
    }
}

像往常一样，提供匹配的自定义也是一个很好的约定：

public class OmitAutoPropertiesForTypesInNamespace : ICustomization
{
    private readonly string ns;

    public OmitAutoPropertiesForTypesInNamespace(string ns)
    {
        this.ns = ns;
    }

    public void Customize(IFixture fixture)
    {
        fixture.Customizations.Add(new OmitPropertyForTypeInNamespace(this.ns));
    } 
}

这最终会让你说：

var fixture = new Fixture();
fixture.Customize(new OmitAutoPropertiesForTypesInNamespace("MyProject"));