Version parsing from namespace bug fix

[dlyz]

When some controller namespace contains segment starting with v, and the next segment contains actual version, then VersionByNamespaceConvention skips second segment due to dividing dot capture.

For example version parsing fails with namespace VersioningSample.V1.Controllers.

This fix uses regex lookahead on trailing dot.

[msftclas]

All CLA requirements met.

[commonsensesoftware]

While it seems this pattern works, I'm not sure this is the full solution. This change only switches from a non-capture to a look-ahead captured as a group.

Alternative 1

I believe the fix can simply be done by requiring the status to have a leading _ as in:

(?:^|\.)[vV](\d{4})?_?(\d{2})?_?(\d{2})?_?(\d+)?_?(\d*)(_([a-zA-Z][a-zA-Z0-9]*))?(?:$|\.)

Alternative 2

The pattern can be more flexible to not require the leading _, but things get a lot uglier:

(?:^|\.)[vV]((\d{4})_?(\d{2})_?(\d{2})_?(\d+)_?(\d*)|(\d{4})_?(\d{2})_?(\d{2})|(\d+)_?(\d*))_?([a-zA-Z][a-zA-Z0-9]*)?(?:$|\.)

This would be the most flexible and comprehensive solution. Everything after v must be either date, major, and minor, date, or major and minor. Then, and only then, can it be followed by a status. The existing pattern is wrong because it ends up capturing ersioningSample as a status which isn't even valid by itself.

Conclusion

Either of these options will require some small amount of code changes because the grouping also changes.

[commonsensesoftware]

I've actually gone ahead and fixed the issue separately in #377, but referenced your PR. The final pattern change just needed to be a set rather than a non-capture group. I added your example to the test suite to prevent future regressions. Thanks for not only reporting the issue, but taking the time to try and fix it. It's appreciated.