Perl and Emacs: Developing tests for progmodes

[Harald Jörg]

Hi emacs-devel,

Emacs comes with two modes to edit Perl sources: the rather
lightweight perl-mode, and the not-so-lightweight cperl-mode. Two
weeks ago I wrote a first ERT test for a bug fix in cperl-mode in
test/lisp/progmodes/cperl-mode-tests.el.

This test has been rewritten so that it can be applied to both
cperl-mode and perl-mode, which is nice.

However, there are bugs in cperl-mode which perl-mode doesn't have,
mostly because perl-mode doesn't offer the functions which fail in the
first place.  So, tests for these bugs need to (require 'cperl-mode),
and they make no sense when testing perl-mode.  I expect most of the
upcoming tests to fall into that category.

To solve this, we could:

 - Split the tests into two and manually copy over tests where this
   makes sense or:

 - Split the tests into a "common" set plus two sets for the specific
   modes (how would the files be named in that case?) or:

 - Keep all tests in one file and tag the individual tests.

Are there any similar cases in the set of Emacs packages, or
conventions how to do it?
-- 
Cheers,
haj