Re: [Boost-users] [Boost.Test] C++ Unit Tests with Boost.Test, Part 1

Subject: Re: [Boost-users] [Boost.Test] C++ Unit Tests with Boost.Test, Part 1
From: Johan Nilsson (r.johan.nilsson_at_[hidden])
Date: 2009-07-07 05:08:09

Gennadiy Rozental wrote:
> Johan Nilsson <r.johan.nilsson <at> gmail.com> writes:
>
>>
>> [This is actually mainly comments to Part 2]
>>
>> Richard wrote:
>>> [Please do not mail me a copy of your followup]
>>>
>>>
> <http://legalizeadulthood.wordpress.com/2009/07/04/c-unit-tests-with-boost-test-part-1/>
>>>
>>> In this post, I will describe how to start making unit tests in C++
>>> with Boost.Test.
>>
>> I've only glanced through the parts, so I might have missed
>> something. Also please note that my comments are very much from a
>> TDD point of view.
>>
>> In Part 2, you recommend using the CHECK macros by default. Being a
>> long-time Boost.Test user (as well as a long-time TDD:er) I strongly
>> believe that by default one should always use the REQUIRE variety of
>> the Boost.Test macros, for a couple of reasons:
>
> This only effectively implements single assertion per test case
> policy, which is what you as hardcore TDDer probably doing anyway.
> For all us other folks CHECK should be default level. REQUIRE should
> be used if you actually require one assertion to pass before you
> proceed to next one.

Hmm, I wouldn't describe myself as "hard-core" TDD:er but, yes, having a 
single assertion per test case is definitely something I aim for. Multiple 
assertions are ok when verifying different aspects of the same logical 
state, but even then such a thing can be split into multiple test cases (or 
fixed by adding a custom assert).

As for REQUIRE vs CHECK there's another point of view IMHO; either the SUT 
works or it does not. Why (in automated testing) bother checking whether 
something "half-works"? If you are into "manually" verifying stuff by 
looking at and interpreting large amounts of output on the screen IMHO 
you're not really doing automated unit/developer testing.

(Ok, so maybe I'm a "medium-core" TDD:er then :)

I still can appreciate that Boost.Test can be used in many testing scenarios 
and strategies, of which one TDD is only one application. The series of blog 
posts though seems to be mainly written as an introduction on how to do 
test-first development with Boost.Test, even though the title starts out 
with "C++ Unit Tests ..." - which could mean many different things. Hence my 
original comments.

Regards,
Johan