Re: [boost] Regression testing unobservable behavior?

Subject: Re: [boost] Regression testing unobservable behavior?
From: Nat Goodspeed (nat_at_[hidden])
Date: 2014-08-08 11:20:46

On Fri, Aug 8, 2014 at 10:39 AM, Beman Dawes <bdawes_at_[hidden]> wrote:

> On Fri, Aug 8, 2014 at 9:53 AM, Peter Dimov <lists_at_[hidden]> wrote:

>> Beman Dawes wrote:

>>>  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"?
>
> That involves some mutually agreed upon way for the handler to inform the
> test framework that it has been invoked, and possibly the other information
> available. Is there a packaged way to handle that communication, or at
> least a pattern for such back channel communication? Or do I have to figure
> it out from scratch every time the need arises?

I can't help thinking that coroutines might be helpful for this
back-channel communication.

Minimally, one could launch the test case on an asymmetric coroutine,
establishing a BOOST_ASSERT handler that passes control back to the
main test logic.

For bullet 3, it would be great to be able to intercept control at the
API level, pass control back to the main test logic and allow it the
opportunity to inject errors (or data) to be verified. That might
require a pair of symmetric coroutines. But to me, the harder part is
the dependency injection.