Re: Dos and don'ts in C++ unit testing?

From:
"Daniel T." <daniel_t@earthlink.net>
Newsgroups:
comp.lang.c++.moderated
Date:
Mon, 19 Feb 2007 12:41:19 CST
Message-ID:
<daniel_t-82705B.07362119022007@news.west.earthlink.net>
"Rune Allnor" <allnor@tele.ntnu.no> wrote:

On 18 Feb, 16:00, Gennaro Prota <clcppm-pos...@this.is.invalid> wrote:

On Fri, 16 Feb 2007 07:59:14 CST, Francis Glassborow wrote:

I generally write a member function then test it before I progress to
writing the next one.


Hmm, I had a look at my code base, and there are a lot of places where
that would have not been possible (as I was expecting): very often one
of the member functions require other member functions to work
(sometimes private member function, but even public ones). Would you
consider that a sign of (possibly) bad design or implementation?


...and what about virtual functions? Does it make sense to specify
a test for a method that will not be implemented for a couple of
inheritance steps?


Certainly! If you are defining a pure virtual member-function, then you
are doing so in the process of creating a context for that function to
be called in (if that isn't the case, then I question the design.) You
want to test to make sure the context uses the virtual correctly.

This means deriving a test class from the abstraction that simply
records when and how the abstraction is used, passing an object of the
test abstraction into the context and then reading the results out of
the test abstraction.

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