Re^2: Does anybody write tests first?

Before learning Perl I wrote some software in Eiffel, and they had that "Design by Contract" paradigm very early, and I used it extensively.

It helped, but it didn't replaced tests.

Why? Because the code has to be run in order to check these precoditions, postconditions, class invariants etc.

And if a method isn't called during testing, all your assertions are vain.

I ended up rerunning the application all over just to make sure these assertions were executed and checked. But the test suite should have done that, not me manually.

There's nothing wrong with DBC (and I like the fact that Perl 6 will come with it by default), but it's just not enough.

Comment on Re^2: Does anybody write tests first?

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Re^3: Does anybody write tests first? by educated_foo (Vicar) on Feb 22, 2008 at 15:07 UTC
And if the code (or "method" -- I need to get my OOOrthodoxy checked) isn't called when you use the program, it probably doesn't matter. If you're writing code you don't use, you've got a more serious problem.	[reply]
Re^4: Does anybody write tests first? by amarquis (Curate) on Feb 22, 2008 at 16:45 UTC
If code isn't called when you routinely use the program, you won't initially find the bug. When the rare case or corner case occurs, though, it'll be a pain in the rear to track that bug down.	[reply]
Re^4: Does anybody write tests first? by cLive ;-) (Prior) on Feb 22, 2008 at 18:46 UTC
Let's just hope you never have to write a script that does X on weekdays or Y on the weekend, but Z if the date is February 29th ;-)	[reply]