HippoMocks -在C++中模拟COM接口？

Question

The latest version of Hippo Mocks (在其Git库中)似乎增加了对COM接口的支持。我曾尝试模拟一个ADO connection对象；这需要对Hippo Mocks进行一些调整才能正确构建(似乎COM版本的代码没有针对其余Hippo Mocks中的更改进行更新)。我现在构建了它，但是下面的测试失败了：

MockRepository mocks;
auto pConn = mocks.Mock<ADONS::_Connection>();
mocks.OnCall(pConn, ADONS::_Connection::AddRef).Return(1);

ADONS::_ConnectionPtr conn = pConn;

智能指针做的第一件事就是AddRef接口。我的mock不应该关心引用计数，所以我添加了一个简单返回1的调用期望。但是，一旦调用AddRef，就会抛出HippoMocks::NotImplementedException。

有没有人成功地用Hippo Mocks模拟了COM接口？

Answer 1

我也遇到了同样的问题并解决了它。hippomocks的实际版本现在发布在github上：

https://github.com/dascandy/hippomocks

非常感谢提供的链接，这有助于找到修复的想法。

更新，有关我的实现和添加的COM支持的详细信息。

首先，我让它工作，下面的测试演示了这一点

class ICom 
{
public:
    virtual ~ICom() {}
    virtual long __stdcall A(void) = 0;
    virtual long __stdcall B(int) = 0;
    virtual long __stdcall C(int, int) = 0;
    ...
};


TEST(checkStdCallBase)
{
    MockRepository mocks;

    ICom* ic = mocks.Mock<ICom>();
    mocks.ExpectCall(ic, ICom::A)
        .Return(1);

    long actual = ic->A();
    EQUALS(1, actual);
}

为了让它工作，我不得不在hippomocks.h中打补丁，这是virtual_function_index方法中最重要的。更正可确保接口上调用的地址计算正确。

其次，我为COM对象添加了一些常见的安装助手，为AddRef、Release和QueryInterface提供了标准行为。

测试展示了如何使用它：

MIDL_INTERFACE("4745C05E-23E6-4c6d-B9F2-E483359A8B89")
COMInterface1 : public IUnknown
{
public:
    virtual HRESULT STDMETHODCALLTYPE getTObjectCount( 
        /* [out] */ unsigned long *pCount) = 0;
};

typedef GUID ESTypeID;

MIDL_INTERFACE("356D44D9-980A-4149-A586-C5CB8B191437")
COMInterface2 : public IUnknown
{
public:
    virtual HRESULT STDMETHODCALLTYPE getMappablePackages( 
        /* [out] */ long *pSize,
        /* [size_is][size_is][out] */ ESTypeID **pIdList) = 0;
};

        TEST(CheckThat_AddCommExpectations_Stubs_QueryInterface_AddRef_Release)
{
    MockRepository mocks; 
    COMInterface1* deviceMock = mocks.Mock<COMInterface1>();

    AddComExpectations(mocks, deviceMock);

    {
        CComPtr<IUnknown> pUnk = deviceMock;  
        CComQIPtr<COMInterface1> pDevice = pUnk;

        CHECK(pDevice == pUnk);

        IUnknown* p = NULL;
        pDevice->QueryInterface(__uuidof(IUnknown), (void**)&p);

        CHECK(p == deviceMock);
    }
}

TEST(CheckThat_ConnectComInterfaces_Stubs_QueryInterface_ToEachOther)
{
    MockRepository mocks; 
    COMInterface1* deviceMock = mocks.Mock<COMInterface1>();
    COMInterface2* devMappingMock = mocks.Mock<COMInterface2>();

    ConnectComInterfaces(mocks, deviceMock, devMappingMock);

    {
        //Com objects can reach each other
        CComQIPtr<COMInterface2> pDevMapping = deviceMock;

        CHECK(pDevMapping != NULL);
        CHECK(pDevMapping == devMappingMock);

        CComQIPtr<COMInterface1> pDevNavigate = devMappingMock;

        CHECK(pDevNavigate != NULL);
        CHECK(pDevNavigate == deviceMock);
    }

}

帮助器方法AddComExpectations和ConnectComInterfaces在单独的头文件"comsupport.h“中提供。header是Hippomock的附加组件：

template <typename T>
void AddComExpectations(HM_NS MockRepository& mocks, T* m)
{
    mocks.OnCall(m, T::AddRef)
        .Return(1);
    mocks.OnCall(m, T::Release)
        .Return(1);
    mocks.OnCall(m, T::QueryInterface)
        .With(__uuidof(T), Out((void**)m))
        .Return(S_OK);

    mocks.OnCall(m, T::QueryInterface)
        .With(__uuidof(IUnknown), Out((void**)m))
        .Return(S_OK);

}

template <typename T1, typename T2>
void ConnectComInterfaces(HM_NS MockRepository& mocks, T1* m1, T2* m2)
{
    //from T1 to T2
    mocks.OnCall(m1, T1::QueryInterface)
        .With(__uuidof(T2), Out((void**)m2))
        .Return(S_OK);
    //from T2 to T1
    mocks.OnCall(m2, T2::QueryInterface)
        .With(__uuidof(T1), Out((void**)m1))
        .Return(S_OK);

    AddComExpectations(mocks, m1);
    AddComExpectations(mocks, m2);

    //no support for interface hierarchies
    //no Base IUnknown -> do it yourself if you really need that special case
}