Re: [Mockpp-devel] Virtual function

[Ewald A. <ew...@ew...>]

Hello,

unfortunately I have no perfect solution. You always need some way to switch 
between production and test. That's probably what you have to pay for 
testability in C++. From my experience you have quite a lot of "unneeded" 
virtuals in the end. Everything else tends to become a bit tricky and more 
verbose.

What is you actual problem? Performance is usually none and security in the 
meaning of preventing to override the method is not safe.

Another solution I can offer is to turn B into a template. Instantiate one for 
production using A and one for testing using mock_A. 

There might as well be some other way of redirection. For example create a 
wrapper template for A/mock_A which helps you to select the correct one:

template <class A_type>
class A_wrapper
{
   A_type *a;
 
  A_wrapper (A_type *an_a)
    :  a(an_a)
    {}

   void test()
   {
     a->A_type::test();
   }
};

Maybe a compiler switch is acceptable which includes a "virtual" while 
compiling debug code:

#ifdef DEBUG
#define DEBUG_VIRTUAL virtual
#else
#define DEBUG_VIRTUAL 
#endif

hope that helps a bit :-)

> Hi,
>
> I have the following code :
>
> class A {
>     public:
>       void test()
>      {
>             // do some stuff
>       }
> }
>
> class A_mock :  public A,  public MOCKPP_NS::MockObject
> {
>    public:
>         A_mock() : ex("counter", 0){};
>
>         void test(
>               ec.inc();
>         );
>
>        ExpectationCounter ex;
> }
>
> class B
> {
>    public :
>         A*     m_A;
>         void f1()
>        {
>                 m_A->test();
>         }
> }
>
> int main ()
> {
>           A_mock*   mock = new A_mock();
>           mock->ex.setExpected(1);
>
>
>           B varB;
>           varB.m_A = mock;
>
>           mock->verify();
> }
>
>
>
> Since the test function in the base class A is NOT virtual, polymorphism
> don't work.  To work, I have to declarw A::test virtual.       My problem,
> is that in my design that function (A::test) should not be a virtual one.
> I find it akward to declare it virtual only for testing.   Any hint on
> doing that kind of test with mockpp?  I don't want to modify the B class.
>
> Thank you and great work on mockpp
>
> Patrick

-- 
Ewald Arnold, Germany
mailto:ewald at ewald-arnold dot de
icq:227435282