Fix parsing of date/time query parameter values with an offset ahead of UTC

[papiomytoglou]

According to the documentation on request matching, Wiremock should be able to handle offsets in date/time query parameter values in all of the following three cases:

/resource?date=2021-06-24T13:40:27+01:00
/resource?date=2021-06-24T13:40:27Z
/resource?date=2021-06-24T13:40:27-01:00

In other words, it should be able to parse a date/time query parameter value with an offset ahead of UTC (+HH:mm), an offset of zero (Z) and an offset behind UTC (-HH:mm).

Right now only the last two work. Offsets ahead of UTC found in query parameters cannot be matched due to the + also having semantics in URL encoding. That is, in URL encoded strings + represents a space and as a result 2021-06-24T13:40:27+01:00 is decoded to 2021-06-24T13:40:27 01:00 which results in a DateTimeParseException.

To avoid that, this PR adds a check to see whether the parameter's value is an ISO-8601 formatted date/time value and, if so, returns it without decoding it first. That way 2021-06-24T13:40:27+01:00 remains as is while hello+world is still decoded to hello world. In other words, the fix only applies to strings that can successfully be parsed by ISO_OFFSET_DATE_TIME, everything else is treated the same as before.

A helpful discussion of the problem above is available in the note found here. The context of the note is Apple technologies, not Java, but this problem is independent of the technologies used.

A unit test which breaks with the current implementation has also been added.

References

Wiremock documentation where the expected behaviour is described: https://wiremock.org/docs/request-matching/#local-vs-zoned

Submitter checklist

• Recommended: Join WireMock Slack to get any help in #help-contributing or a project-specific channel like #wiremock-java
• The PR request is well described and justified, including the body and the references
• The PR title represents the desired changelog entry
• The repository's code style is followed (see the contributing guide)
• Test coverage that demonstrates that the change works as expected
• For new features, there's necessary documentation in this pull request or in a subsequent PR to [wiremock.org](https://github.com/wiremock/wiremock.org)

[dieppa]

Thanks, @papiomytoglou , we are reviewing it 👀

[dieppa]

Thanks @papiomytoglou ,

Reviewed and merged!