Re: Passing Pointers -- where to delete them
On 4 mar, 19:02, Ian Collins <ian-n...@hotmail.com> wrote:
James Kanze wrote:
On Mar 4, 10:45 am, Ian Collins <ian-n...@hotmail.com> wrote:
James Kanze wrote:
[...]
I guess we bent the rules for our singleton objects to enable
then to be created and destroyed in tests. The single
instance is enforced through a base class template with a
static member pointer.
The problem with this is that you're no longer testing the code
you actually use.
No, the code is the code we actually use.
But the context it's tested in isn't. Especially if you're
"resetting" a singleton. (I suppose that if you're actually
destructing the object, and renew'ing it, the difference is
minor. But I can still imagine cases where it might make a
difference.)
Don't forget that everything I or my team writes is written
test first, so the only thing is actual production code.
Except, of course, that it's running in a different environment.
That's partially unavoidable, of course, but in code that I
expect to be run before main(), I do ensure that it's tested
running before main(). (One problem I've seen in the past is
using std::cout or std::cerr before they've been constructed.
Regretfully, even ensuring that you're testing the code before
main doesn't ensure that you're verifying that it takes the
necessary steps to avoid this---it's quite possible that just by
chance, the objects were constructed first anyway.)
I use cppUnit, creating and deleting singletons in the setUp()
and trearDown() methods.
Doesn't cppUnit support tests using separate processes? If
not, that sounds seriously limiting.
It might, but I've never had cause to look...
I suspect it does. It's got a pretty good reputation. But
designing a test harness to test things like correctly defending
against order of initialization problems is very difficult. For
the same reason that you have the problems to begin with: you
can't ensure externally that A is constructed before B, and you
can't ensure externally that it isn't, so you can't test your
defensive measures.
--
James Kanze (GABI Software) email:james.kanze@gmail.com
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