Test!

No code is complete (and some would say it's broken) without a good amount of testing, and CodeTalker provides a simple way to test your rules individually, to ensure the best coverage.

the tests for our CSS grammar are contained in tests/grammar.py. To run them (ensure you have py.test installed, then) py.test tests/grammar.py. Or just ./setup.py test to run all of them.

The codetalker/testing.py currently only has one function, but it will setup valitation tests for rule parsing.

Here it is in action:

import css.grammar as grammar
from codetalker import testing

parse_rule = testing.parse_rule(__name__, grammar.grammar)

parse_rule(grammar.class_, (
    '.one',
    '.green',
    '.GReEn',
    '.div',
    ), (
    'one',
    ))

parse_rule(grammar.simple_selector, ( # should pass
    'div',
    'div#some',
    'div#one.green',
    'div.frown',
    'ul.cheese:first-child',
    'li.one.two.three',
    'a#b.c.d:last-child',
    ), (                              # should fail
    'one',
    'div# and',
    'div. one',
    ))

When you do that, parse_rule sets up a verification test for each string.

To get your very own factory function, call parse_rule = testing.parse_rule(__name__, the_grammar) (it needs your module's __name__ in order to setup the functions in your global namespace, where py.test can recognize and run them.

Then for each rule you want to test, call parse_rule(the_rule, passing_strings, failing_strings.

This method of incremental testing is really a boon while you are initially creating your grammar — this way, you don't have to complete the grammar before you test parts of it out.

Now, in addition to just grammar testing, you should have some testing of your translation as well, but the nature of those tests depends completely on your specific project.