Re: Concrete classes considered harmful

From	Ian Collins <ian-news@hotmail.com>
Newsgroups	comp.lang.c++
Subject	Re: Concrete classes considered harmful
Date	2015-07-14 10:35 +1200
Message-ID	<d0isptFflldU5@mid.individual.net> (permalink)
References	<y42dnfPZC9VKGj3InZ2dnUU78Q-dnZ2d@giganews.com> <d0dtm9FegarU8@mid.individual.net> <mo0sfb$hgq$3@news.xmission.com> <d0imfgFflldU3@mid.individual.net> <mo1cig$r93$4@news.xmission.com>

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Richard wrote:
> [Please do not mail me a copy of your followup]
>
> Ian Collins <ian-news@hotmail.com> spake the secret code
> <d0imfgFflldU3@mid.individual.net> thusly:
>
>> Richard wrote:
>>> Ian Collins <ian-news@hotmail.com> spake the secret code
>>> <d0dtm9FegarU8@mid.individual.net> thusly:
>>>
>>>> Given the three options of abstract, concrete without non-trivial inline
>>>> member functions or Pimpl classes all are equally simple to mock.
>>>
>>> I'm guessing you're using a lot of link-time mocking?
>>
>> Yes.  A lot of my work is low level system code and down there I'll be
>> mocking mainly C libraries.
>
> OK, given that confirmation, have you looked at cgreen?  It's a unit
> test framework built specifically around link-time mocking and the use
> of C.

No, I haven't.  I use my own mocking framework that is unit test 
framework neutral (it's been used with CppUnut, CxxTest and Google 
Test).  I prefer to keep the two coupled so I can use my framework with 
whatever unit test setup a client uses.

> All my TDD work has been in C++ where I could use static or
> dynamic polymorphism for mocking out collaborators, so I haven't used
> link-time mocking.  However, I can see it's usefulness.

It's pretty much the only option when you are working with system (or 
object only third party) libraries.

My approach has been to apply the same techniques to pure C++ code and 
mixed C and C++.  This leads to an unconventional approach to pure C++ 
code where it is the individual class member functions that are mocked, 
rather than class instances.  While this may appear odd, I've found most 
test cases revolve around checking passed parameter values and responses 
to returned values.  In these cases, being able to use the code 
generated by the framework rather than having to write mock objects 
saves a lot of work.

-- 
Ian Collins

Thread

Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-11 04:04 +0100
  Re: Concrete classes considered harmful Ian Collins <ian-news@hotmail.com> - 2015-07-11 15:09 +1200
    Re: Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-11 17:49 +0100
      Re: Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-11 18:10 +0100
        Re: Concrete classes considered harmful Martin Shobe <martin.shobe@yahoo.com> - 2015-07-11 13:33 -0500
      Re: Concrete classes considered harmful Ian Collins <ian-news@hotmail.com> - 2015-07-12 09:17 +1200
        Re: Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-12 01:51 +0100
          Re: Concrete classes considered harmful Ian Collins <ian-news@hotmail.com> - 2015-07-12 13:20 +1200
            Re: Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-12 02:32 +0100
              Re: Concrete classes considered harmful Ian Collins <ian-news@hotmail.com> - 2015-07-12 15:48 +1200
                Re: Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-12 13:46 +0100
              Re: Concrete classes considered harmful Ian Collins <ian-news@hotmail.com> - 2015-07-12 16:14 +1200
                Re: Concrete classes considered harmful legalize+jeeves@mail.xmission.com (Richard) - 2015-07-13 17:46 +0000
                Re: Concrete classes considered harmful Ian Collins <ian-news@hotmail.com> - 2015-07-14 08:52 +1200
                Re: Concrete classes considered harmful legalize+jeeves@mail.xmission.com (Richard) - 2015-07-13 22:01 +0000
            Re: Concrete classes considered harmful legalize+jeeves@mail.xmission.com (Richard) - 2015-07-13 17:28 +0000
              Re: Concrete classes considered harmful Ian Collins <ian-news@hotmail.com> - 2015-07-14 08:47 +1200
                Re: Concrete classes considered harmful legalize+jeeves@mail.xmission.com (Richard) - 2015-07-13 22:02 +0000
                Re: Concrete classes considered harmful Ian Collins <ian-news@hotmail.com> - 2015-07-14 10:35 +1200
                Re: Concrete classes considered harmful legalize+jeeves@mail.xmission.com (Richard) - 2015-07-14 04:52 +0000
                Re: Concrete classes considered harmful Ian Collins <ian-news@hotmail.com> - 2015-07-14 19:31 +1200
                Re: Concrete classes considered harmful legalize+jeeves@mail.xmission.com (Richard) - 2015-07-15 16:57 +0000
                Re: Concrete classes considered harmful Ian Collins <ian-news@hotmail.com> - 2015-07-16 09:49 +1200
                Re: Concrete classes considered harmful legalize+jeeves@mail.xmission.com (Richard) - 2015-07-16 15:53 +0000
                Re: Concrete classes considered harmful Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-10-08 13:20 +0000
                Re: Concrete classes considered harmful legalize+jeeves@mail.xmission.com (Richard) - 2015-10-12 20:48 +0000
      Re: Concrete classes considered harmful Juha Nieminen <nospam@thanks.invalid> - 2015-07-12 11:32 +0000
        Re: Concrete classes considered harmful Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2015-07-12 13:46 +0100
          Re: Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-12 13:54 +0100
            Re: Concrete classes considered harmful Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2015-07-12 14:21 +0100
              Re: Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-12 14:40 +0100
                Re: Concrete classes considered harmful Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2015-07-12 14:59 +0100
    Re: Concrete classes considered harmful legalize+jeeves@mail.xmission.com (Richard) - 2015-07-13 17:08 +0000
      Re: Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-13 19:59 +0100
      Re: Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-13 20:06 +0100
  Re: Concrete classes considered harmful "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com> - 2015-07-11 05:11 +0200
    Re: Concrete classes considered harmful legalize+jeeves@mail.xmission.com (Richard) - 2015-07-13 17:10 +0000
  Re: Concrete classes considered harmful "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com> - 2015-07-11 06:07 +0200
    Re: Concrete classes considered harmful woodbrian77@gmail.com - 2015-07-11 14:12 -0700
  Re: Concrete classes considered harmful Paavo Helde <myfirstname@osa.pri.ee> - 2015-07-11 02:06 -0500
    Re: Concrete classes considered harmful JiiPee <no@notvalid.com> - 2015-07-11 08:28 +0100
    Re: Concrete classes considered harmful Reinhardt Behm <rbehm@hushmail.com> - 2015-07-11 15:48 +0800
  Re: Concrete classes considered harmful Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2015-07-12 00:16 +0100
    Re: Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-12 01:52 +0100
  Re: Concrete classes considered harmful David Harmon <source@netcom.com> - 2015-07-12 06:58 -0700
    Re: Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-12 15:45 +0100
  Re: Concrete classes considered harmful Mr Flibble <flibble@i42.co.uk> - 2015-07-12 16:30 +0100
    Re: Concrete classes considered harmful woodbrian77@gmail.com - 2015-07-12 11:23 -0700
      Re: Concrete classes considered harmful "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com> - 2015-07-12 21:37 +0200
        Re: Concrete classes considered harmful woodbrian77@gmail.com - 2015-07-12 14:34 -0700
      Re: Concrete classes considered harmful Luca Risolia <luca.risolia@linux-projects.org> - 2015-07-13 00:38 +0200

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