Mocks and std::unique_ptr

[ghost]

How am I supposed to pass a mock as unique pointer?

For example:

class Object
{
public:
    ~Object() {}
    virtual void DoSomething() = 0;
};

class Handler
{
public:
    explicit Handler(std::unique_ptr<Object> SomeObject)
        : m_Object(std::move(SomeObject))
    {
    }

    void Handle()
    {
        m_Object->DoSomething();
    }

private:
    std::unique_ptr<Object> m_Object;
};

TEST()
{
    Mock<Object> ObjectMock;
    When(Method(ObjectMock, DoSomething)).AlwaysReturn();
    Object* SomeObject = &ObjectMock.get();

    Handler SomeHandler(make_unique(SomeObject));
    SomeHandler.Handle();

    Verify(Method(ObjectMock, DoSomething)).Once();
}

This code crashes on exiting the test because both Mock and Handler take ownership of the Object instance. Could you add some release method to Mock which releases ownership but still holds a weak reference to the object? Or is there another way to handle this?

[eranpeer]

Hi,
I made some changes trying to make Fakeit support your request, though i had to revert them all back since for some reason it does not work on gcc.
Things get tricky since the instance held by the mock is not a real instance (since the mocked class is abstract). It is a faked instance managed by the mock object. Letting the test/user delete the instance fails because the FakeObject's virtual table does not have a destructor.
I will make another effort in the next few days to make it work (by putting a fake destructor in the correct position of the virtual table) I hope I will be able to make it work.

[eranpeer]

Ok, It works! You can mock the dtor now!
The following code will work:

Mock<SomeInterface> mock;
Fake(Dtor(mock)); // Stub the dtor to do nothing!!
SomeInterface * i = &mock.get();
std::unique_ptr<SomeInterface> ptr(i);

You can do much more than that:

void mock_virtual_dtor_with_when() {
  int a = 0;
  Mock<SomeInterface> mock;
  When(Dtor(mock)).Do([&](){a++; });
  SomeInterface * i = &(mock.get());
  delete i; // a++
  delete i; // a++
  ASSERT_EQUAL(2, a);
}

Enjoy!

[ghost]

Thanks for your effort! I will certainly try this out next week.

[ghost]

Hi, it works fine now. I have just a small remark:

At this line GCC 4.8 gives the warning ISO C++ forbids casting between pointer-to-function and pointer-to-object. Is there something we could do to avoid that warning?

[eranpeer]

Sure, I'll fix it this weekend.
On Feb 5, 2015 9:37 AM, "Stijn Van Nieuwenhuyse" notifications@github.com
wrote:

Hi, it works fine now. I have just a small remark:

At this
https://github.com/eranpeer/FakeIt/blob/master/include/mockutils/gcc/VirtualTable.hpp#L80
line GCC 4.8 gives the warning ISO C++ forbids casting between
pointer-to-function and pointer-to-object. Is there something we could do
to avoid that warning?

—
Reply to this email directly or view it on GitHub
#10 (comment).

[eranpeer]

Done! I fixed the gcc warning.

[misery]

I have a similar crash here with Qt's QSharedPointer. Used current master branch!

#0 0x685d62 in fakeit::MethodProxyCreator<void>::methodProxy(unsigned int) [..]/external/fakeit.hpp:5815:20
#1 0x685459 in void fakeit::MethodProxyCreator<void>::methodProxyX<0>() [..]/external/fakeit.hpp:5820:20
#2 0x689a89 in fakeit::VirtualTable<ActivationContext>::dtor(int) [..]/external/fakeit.hpp:5615:13
#3 0x7fc23f73049f in QScopedPointerDeleter<ActivationContext>::cleanup(ActivationContext*) [..]/QtCore/qscopedpointer.h:54:9
#4 0x7fc23f730028 in QScopedPointer<ActivationContext, QScopedPointerDeleter<ActivationContext> >::~QScopedPointer() [..]/QtCore/qscopedpointer.h:101:9

The code:

Mock<ActivationContext> context;
When(Dtor(context));

QSharedPointer<AuthModel> model(new AuthModel(&context.get()));

[jessevdp]

What happens when both the mock and the unique_ptr (that points to the mocked instance) are deleted?

{
Mock<SomeType> mock;
Fake(Dtor(mock));
std::unique_ptr<SomeType> ptr {&mock.get()};
} // <- both are deleted

I'm having some issues and I suspect it has to do with this..