Unit tests and verifying pre/post-conditions and invariants

[Jonathan M Davis]

On Monday, August 16, 2010 14:36:13 Steven Schveighoffer wrote:
> On Sat, 14 Aug 2010 23:49:18 -0400, Jonathan M Davis
> 
> <jmdavisprog at gmail.com> wrote:
> > and I wanted to test to make sure that func() couldn't be called with
> > any int
> > greater or equal to 8, what would I do? The best that I can think of is
> > to catch
> > an AssertError and ignore it. e.g.
> > 
> > unittest
> > {
> > 
> >     try
> >     {
> >     
> >         func(8);
> >         assert(0);
> >     
> >     }
> >     catch(AssertionError ae)
> >     {}
> > 
> > }
> 
> BTW, I just realized, this code doesn't test anything.  You want something
> like this:
> 
> unittest
> {
>     bool caughtAssert = false;
>     try
>     {
>        func(8);
>     }
>     catch(AssertionError ae)
>     {
>        caughtAssert = true;
>     }
>     assert(caughtAssert);
> }
> 
> -Steve

Ah, that would be true, since assert throws an AssertException. Whoops. It does 
work for normal exceptions though (assuming that you changed the type in the 
catch to the appropriate exception type).

- Jonathan M Davis