Re: [Boost-users] [Unit-Test] How to test private functions

From: Ed Johnson (ed_at_[hidden])
Date: 2006-05-03 02:32:37

Ed Johnson wrote:
> Gennadiy Rozental wrote:
>>> Is there a way to test the private functions of a class without moving
>>> them into public scope during test?
>>>
>>> What are some strategies for this?
>>>
>>> I was hoping to add "friend class boost::unit_test::test_suite;" to my
>>> class but that didn't work.
>> Putting aside "why would you need that" question, simple answer is: define 
>> test case as a friend to your class. For example if you want to implement 
>> test case as free function:
>>
>> class Foo {
>>   friend void foo_test();
>>
>>   void private_method();
>> };
>>
>> void foo_test()
>> {
>>     Foo f;
>>
>>    f.private_method();
>> }
>>
>> If you need multiple test cases having access to the internals you could 
>> define test class and make it friend of your class. Next all your test cases 
>> will instantiate test class and run test methods.
>>
>> Gennadiy
> 
> In my tests, it does not appear possible to use the auto_unit_test.hpp 
> macros in a test class that is attempting to be a friend of a testee 
> class.  The compiler complains that the test class is trying to access 
> private data.  Does anyone know how to make them work together?
> (Should this be a separate thread, or is it alright to add it to this one?)
> 
> Thanks,
> 
> Ed

Whoops, it appears to work just fine with auto_unit_test.hpp macros. My 
mistake. This is certainly a better way to test the private data than 
the preprocessor definitions strategy I mentioned in my other post.

-Ed

--Foo.hpp--

class Foo
{
   friend void foo_test();

private:
   void private_method();

};

--TestFoo.cpp--

#define BOOST_AUTO_TEST_MAIN

#include "Foo.hpp"

BOOST_AUTO_TEST_SUITE( my_suite );

     BOOST_AUTO_TEST_CASE( foo_test )
     {
         Foo f;
        f.private_method();
     }

BOOST_AUTO_TEST_SUITE_END();