On 2010-11-21 02:34, Jonathan M Davis wrote:
On Saturday 20 November 2010 16:23:32 Jonathan M Davis wrote:
The lazy solution sounds pretty good actually. Can anyone think of any real
downsides to that? So, it would look something like
assertExcThrown(E : Throwable, T)(lazy T, string file = __FILE__, size_t
line = __LINE__);
Wait. No. I didn't think that one through enough. It doesn't work. You You don't
actually get a delegate out of lazy, and what you need for assertExcThrown!() is
a delegate. It would be great to be able to implicitly create a delegate like
that, but lazy does it underneath the hood, so to speak, and when the function
call is made, you still get the result of the function call, and by that point,
it's too late, since to get the result of the function call, you obviously need
to have called it. So, the question remains whether it would be better to pass a
string which gets mixed in or a delegate which gets called.
Ok, now I'm not sure what you mean. If you don't get a delegate what do
you get? And what to you mean by "and by that point, it's too late", do
late for what?
I think that the delegate solution is uglier to use, but that's debatable. It's
less efficient at runtime, but it would be faster to compile and would result in
less code bloat (though how much code bloat matters for unit tests is debatable,
since they shouldn't end up in released binaries). I'm really not sure which is
better. I like the mixin solution, but the delegate solution has its advantages
as well.
Anyone else have an opinion on whether (and why) the string mixin approach or
the delegate approach is better?
- Jonathan M Davis
This works according to the documentation of assertExcThrown:
void foo (int, int)
{
throw new Throwable("");
}
void assertExcThrown (E = Throwable, T) (lazy T dg, string file =
__FILE__, size_t line = __LINE__)
{
bool thrown;
try
dg();
catch (E e)
thrown = true;
if (!thrown)
throw new AssertError(format("assertExcThrown() failed: No %s
was thrown.", E.stringof), file, line);
}
void main ()
{
assertExcThrown(foo(3, 4));
}
--
/Jacob Carlborg
