[racket-dev] RFC: Coding Guidelines

On Thu, Aug 19, 2010 at 9:48 AM, Robby Findler
<robby at eecs.northwestern.edu> wrote:
> On Thu, Aug 19, 2010 at 8:44 AM, Sam Tobin-Hochstadt <samth at ccs.neu.edu> wrote:
>> On Tue, Aug 17, 2010 at 3:57 PM, Jay McCarthy <jay.mccarthy at gmail.com> wrote:
>>> Please comment.
>>
>> I think that this:
>>
>> "Your first task when changing old code is to build an adequate test
>> suite to ensure you do not introduce new mistakes as you attempt to
>> improve it. Thank you for improving the world for future generations!"
>>
>> is too demanding.  There are enormous areas of our code that don't
>> have a test suite.  How comprehensive a test suite do I need before
>> changing slideshow?  Or scribble (which has a test suite for the
>> syntax, but not the language)?
>
> You should make a reasonable effort to put in a test case or two for
> the specific functionality that you're adding/modifying. If there is
> no test suite and you aren't sure how to build one, then ask, see what
> responses you get, and go from there.

So, to make this concrete, I recently made some small changes to the
scriblib/autobib library.  These included changing the regexp to allow
hyphens in last names, as well as allowing multiple citations at once
in a particular special case.  I tested these changes by running a
not-then-published paper that I was working on, and seeing that it did
the right thing.  Then I sent the patch to Matthew, and he said it
looked good.  Then I committed it.

There's two forms of automated test that I could have added.  I could
have just added a file the used the functionality, and checked that it
didn't error when run.  That would have been a minimal test, and
wouldn't even have exercised the bug fix (it was just parsing my name
wrong).   Or I could have written a test framework for Scribble PDF
rendering.  I'm not sure how that would have worked, and it would have
been a big programming investment.  I don't think I had time then (or
now) to do that work.

For Typed Racket, testing is a hard problem, but one that I've put a
bunch of effort into making possible, because it needs testing.  But
there's no way I'd expect someone else to put that effort in.
-- 
sam th
samth at ccs.neu.edu