Convert Drupal.t and Drupal.formatPlural regular expressions to extended form.

As I've said in person, this looks so much better. It is way cleaner to understand what is going on here. Do tests cover this already? If that is the case, this looks like just ready to go :)

Superb, looking forward to testing results.

Looks good, test looks pretty comprehensive and passes :) Thanks for your work.

The time increase in what takes PCRE to parse the string compared to parsing the string and throwing away whitespace and comments is barely measurable compared to actually running the PCRE state machine. Edit: I microbenchmarked this and on my machine 10 000 runs adds 0.02s time to the execution of the PCRE so every run we are talking of two microseconds. We can tolerate a 2us slowdown for readability.

+    file_put_contents($filename, $contents);

I don't see any reason to create the file in the test rather than just ship it inside locale/tests - also not 100% but does simpletest even mess with the file directory during test runs or is this something which would have to be cleared up manually (which isn't done by the test if so).

@loganfsmyth: the direct backportable solution IMHO would be to put a locale.test.js or locale_test.js or somesuch in modules/locale/. Not sure what's the pattern, locale.test.js or locale_test.js though. Probably other tests have js test files, for aggregation testing for example to look for naming patterns.

Looks good to me. Also, this should be backported to D7 (should apply direct). It is just about making the JS parser code more understandable and adding a heap of tests to verify.

Committed to 8.x. Moving to 7.x for Angie to consider.

It looks to me like this broke 8.x; most likely there were missing files that didn't get committed.

http://qa.drupal.org/8.x-status

file_get_contents(modules/locale/tests/locale_test.js): failed to open stream: No such file or directory

It is critical if its broke. We also have the file to commit, so RTBC.

I've attached the modules/locale/tests/locale_test.js hunk from the patch in #11 for ease.

All right, @Dries added the file in. The D7 patch is in #11. :)
Edit: commit link at http://drupalcode.org/project/drupal.git/commitdiff/3c536d68db761d7a9e60...

Uploading again to make it clear this patch is for D7. Should be RTBC if tests pass, just like D8.

Should be good to go (not my patch, I just reposted it above :).

Seems like this is no functional change, just makes everything a hell of a lot easier to understand and also adds more tests which is always a good thing. :)

Committed and pushed to 7.x. Thanks!

Superb, thanks, now onwards to #488496: Implement missing msgctx context in JS translation for feature parity with t() :)

Tagging for UI translation.