带有参数的构造函数 () 扩展方法调用构造函数

Question

根据FakeItEasy教程此处所述，WithArgumentsForConstructor()扩展方法不会调用类构造函数：

// Specifying arguments for constructor using expression. This is refactoring friendly!
// The constructor seen here is never actually invoked. It is an expression and it's purpose
// is purely to communicate the constructor arguments which will be extracted from it
var foo = A.Fake<FooClass>(x => x.WithArgumentsForConstructor(() => new FooClass("foo", "bar")));

然而，在下面的测试中，我的Person类构造函数中的断点被触发了。为什么会这样？我是否错误地使用了WithArgumentsForConstructor()？

[Test]
public void Constructor_With_Arguments()
{
    var driver = A.Fake<Person>(x => x.WithArgumentsForConstructor(() => new Person("Jane", 42)));
    var age = driver.GetAge();
    Assert.AreEqual(42, age);
}

堆栈跟踪：

MyStuff.Tests.Domain.dll!MyStuff.Tests.Domain.Driver.Person(string name, int age) Line 61   C#
DynamicProxyGenAssembly2!Castle.Proxies.DriverProxy.DriverProxy(Castle.DynamicProxy.IInterceptor[] value, string value, int value)  Unknown
[Native to Managed Transition]  
[Managed to Native Transition]  
mscorlib.dll!System.RuntimeType.CreateInstanceImpl(System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfo culture, object[] activationAttributes, ref System.Threading.StackCrawlMark stackMark)  Unknown
mscorlib.dll!System.Activator.CreateInstance(System.Type type, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfo culture, object[] activationAttributes) Unknown
mscorlib.dll!System.Activator.CreateInstance(System.Type type, object[] args)   Unknown
FakeItEasy.dll!Castle.DynamicProxy.ProxyGenerator.CreateClassProxyInstance(System.Type proxyType, System.Collections.Generic.List<object> proxyArguments, System.Type classToProxy, object[] constructorArguments)  Unknown
FakeItEasy.dll!Castle.DynamicProxy.ProxyGenerator.CreateClassProxy(System.Type classToProxy, System.Type[] additionalInterfacesToProxy, Castle.DynamicProxy.ProxyGenerationOptions options, object[] constructorArguments, Castle.DynamicProxy.IInterceptor[] interceptors) Unknown
FakeItEasy.dll!FakeItEasy.Creation.CastleDynamicProxy.CastleDynamicProxyGenerator.GenerateClassProxy(System.Type typeOfProxy, System.Collections.Generic.IEnumerable<object> argumentsForConstructor, Castle.DynamicProxy.IInterceptor interceptor, System.Collections.Generic.IEnumerable<System.Type> allInterfacesToImplement)   Unknown
FakeItEasy.dll!FakeItEasy.Creation.CastleDynamicProxy.CastleDynamicProxyGenerator.DoGenerateProxy(System.Type typeOfProxy, System.Collections.Generic.IEnumerable<System.Type> additionalInterfacesToImplement, System.Collections.Generic.IEnumerable<object> argumentsForConstructor, Castle.DynamicProxy.IInterceptor interceptor)   Unknown
FakeItEasy.dll!FakeItEasy.Creation.CastleDynamicProxy.CastleDynamicProxyGenerator.CreateProxyGeneratorResult(System.Type typeOfProxy, System.Collections.Generic.IEnumerable<System.Type> additionalInterfacesToImplement, System.Collections.Generic.IEnumerable<object> argumentsForConstructor, FakeItEasy.Core.IFakeCallProcessorProvider fakeCallProcessorProvider)    Unknown
FakeItEasy.dll!FakeItEasy.Creation.CastleDynamicProxy.CastleDynamicProxyGenerator.GenerateProxy(System.Type typeOfProxy, System.Collections.Generic.IEnumerable<System.Type> additionalInterfacesToImplement, System.Collections.Generic.IEnumerable<object> argumentsForConstructor, FakeItEasy.Core.IFakeCallProcessorProvider fakeCallProcessorProvider) Unknown
FakeItEasy.dll!FakeItEasy.Creation.CastleDynamicProxy.CastleDynamicProxyGenerator.GenerateProxy(System.Type typeOfProxy, System.Collections.Generic.IEnumerable<System.Type> additionalInterfacesToImplement, System.Collections.Generic.IEnumerable<object> argumentsForConstructor, System.Collections.Generic.IEnumerable<System.Reflection.Emit.CustomAttributeBuilder> customAttributeBuilders, FakeItEasy.Core.IFakeCallProcessorProvider fakeCallProcessorProvider)  Unknown
FakeItEasy.dll!FakeItEasy.Creation.ProxyGeneratorSelector.GenerateProxy(System.Type typeOfProxy, System.Collections.Generic.IEnumerable<System.Type> additionalInterfacesToImplement, System.Collections.Generic.IEnumerable<object> argumentsForConstructor, System.Collections.Generic.IEnumerable<System.Reflection.Emit.CustomAttributeBuilder> customAttributeBuilders, FakeItEasy.Core.IFakeCallProcessorProvider fakeCallProcessorProvider)  Unknown
FakeItEasy.dll!FakeItEasy.Creation.FakeObjectCreator.GenerateProxy(System.Type typeOfFake, FakeItEasy.Creation.FakeOptions fakeOptions, System.Collections.Generic.IEnumerable<object> argumentsForConstructor) Unknown
FakeItEasy.dll!FakeItEasy.Creation.FakeObjectCreator.CreateFake(System.Type typeOfFake, FakeItEasy.Creation.FakeOptions fakeOptions, FakeItEasy.Creation.IDummyValueCreationSession session, bool throwOnFailure)   Unknown
FakeItEasy.dll!FakeItEasy.Creation.DefaultFakeAndDummyManager.CreateFake(System.Type typeOfFake, FakeItEasy.Creation.FakeOptions options)   Unknown
FakeItEasy.dll!FakeItEasy.Creation.DefaultFakeCreatorFacade.CreateFake<SysSurge.DynMock.Tests.Domain.Driver>(System.Action<FakeItEasy.Creation.IFakeOptionsBuilder<SysSurge.DynMock.Tests.Domain.Driver>> options)  Unknown

...

- user152949

Answer 1

你使用得没问题。

但你的理解有误。

// The constructor seen here is never actually invoked...

这意味着它不会在此处调用构造函数。它将解析此表达式并使用参数在某个地方内部调用构造函数。但是它将调用构造函数。

您可以检查此操作以在表达式内部设置断点。

- MaKCbIMKo