[Python-Dev] Regexp 2.7

[Terry Reedy]

Jared Grubb wrote:
> I'm not criticizing the current battery of tests, nor am I arguing that 
> we replace them.
> 
> There's a comment in the test_re.py that says that "these tests were 
> carefully modeled to cover most of the code"... That is a very difficult 
> statement to maintain and/or verify, especially if the library gets a 
> major revision (which it appears the original post's patch is).
> 
> PCRE has _thousands_ of detailed regular expression tests, testing 
> everything from matching to parsing to extended regular expression 
> syntax to encoding and locales. (It's been a while since I've looked at 
> the details, but of course there are tests that dont apply to Python's 
> implmentation.)
> 
> So, if there's interest in investigating how much of the PCRE tests can 
> augment the existing tests, I am offering to do so. (I already did a 
> simple translation utility to parse the PCRE test format into something 
> we could use in the PyPy test suite; I could try to do something similar 
> for test_re, if there's interest).

There is a conflict between running a thorough test of everything 
possible and not having the test suite run for hours.  I believe a 
couple of other modules have a regular sanity-check test and an extended 
patch-check test.  Something like that might be appropriate for re.