Re: [boost] Regression testing unobservable behavior?

Subject: Re: [boost] Regression testing unobservable behavior?
From: Peter Dimov (lists_at_[hidden])
Date: 2014-08-08 10:53:30

Beman Dawes wrote:
On Fri, Aug 8, 2014 at 9:53 AM, Peter Dimov <lists_at_[hidden]> wrote:
>
> > Beman Dawes wrote:
> >
> >>  Certain library function errors are difficult to regression test 
> >> because it is not obvious how to observe their behavior in a test 
> >> framework.
> >> Examples include:
> >>
> >>  ...
> >
> >  2) Verification that BOOST_ASSERT fires when a precondition is 
> > violated.
> >
> > You can do this by enabling a custom assert handler and then test that 
> > it has been invoked.
>
> Yes, but the question in my mind is how to "test that it has been 
> invoked"?

I just do the obvious: increment an "assertion_failed_" global variable in 
the handler, then BOOST_TEST that it has been incremented the correct number 
of times.

It's a bit ad-hoc, but it works.