Performance vs. Testability and semi-virtual method calls

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Published Monday, July 11, 2005 1:58 AM by RoyOsherove
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Comments

Sunday, July 10, 2005 10:33 PM by Yaniv

# re: Performance vs. Testability and semi-virtual method calls

it's a novel idea, and can be very useful, but I'm not sure the "#ifdef(UNIT_TEST) virtual #endif" is always a good idea.
I think testing a different code than your production can bite you in the back sometimes.
for example, what if some code functional;ity or performance changes when the function is made virtual? if this is C++, you can end up changing the behvior of the class (or make it have a VMT where it didn't before), and even in safer languages like C#, I can imagine cases where this would fail . Why not define those virtual to start with, but mark them in some way (e.g. comment which you WILL verify before shipping) to be made non-virtual if that makes sense when the product is done?
Monday, July 11, 2005 4:37 AM by Roy Osherove

# re: Performance vs. Testability and semi-virtual method calls

Yaniv: That's a good point: What if by the fact that you're testing ,you've changed the behavior of the code? That's why I think the first bullet point in this post is the first one I'd choose: have known optimization points, but don't optimize until you need to.
The last point lets a team with strict design rules still have unit tests and thus minimize bug risks and still keep playing by the "rules" of the team. It's a settlement - not an overall solution, and a lot of teams find it "good enough".
Wednesday, July 13, 2005 2:47 AM by Tomer Gabel

# re: Performance vs. Testability and semi-virtual method calls

Just a thought: as long as you're using macros, there's nothing worse than #ifdefs all over the place. Just #define a macro, say TESTVIRTUAL, then:

#ifdef UNIT_TEST
#define TESTVIRTUAL virtual
#endif

Then you can just

public:
TESTVIRTUAL void testpoint()...

Macros are awesome as long as they're using sparingly...
Saturday, November 17, 2007 4:31 PM by Nati Dobkin

# Testable code – is it worth it?

Recently I been refactoring some legasy code and writing a new one. I am using Rhino mocks to run my