Handle JSON serialized Dates from JavaScript in LocalDateDeserializer

[sandermak]

I've been at this before (#28), however, during the review phase of the PR I accidentally borked my own use-case. Unfortunately I only found out after we switched from our internally patched version to the current 2.7 release.

It's now possible to parse a date and time ("2016-01-18T15:41:32.232") as LocalDate. However, what I needed was to be able to parse this, coming from JavaScript:

new Date().toJSON()
"2016-01-18T14:09:30.163Z"

(notice the trailing Z, which is currently not accepted)

JavaScript generates an ISO instant string when serialising a JavaScript Date [1]. It seems I am not the only one running into this issue [2]. I think it would be great to revise my original PR to allow for this. That way, it works for many people doing Java/JS interop without having to override the pattern on each usage of a LocalDate field. The check for custom formatter (https://github.com/FasterXML/jackson-datatype-jsr310/issues/37) is obviously still in place. I also made the check for the presence of the time component a bit more robust.

Thanks for considering this PR. My CLA is already in place, so that should not be an issue.

[1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toJSON & https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toISOString
[2] http://stackoverflow.com/questions/26233882/javascript-date-to-java-time-localdate & http://stackoverflow.com/questions/5591967/how-to-deserialize-js-date-using-jackson

[cowtowncoder]

Thank you for following up on this. This will be in 2.7.1 then.

[sandermak]

Awesome, thanks for being so responsive and running this great project!

[cowtowncoder]

@sandermak No problem; good to have active contributors to catch remaining issues!

[cbornet]

I think using a formatter

ISO_DATE_OPTIONAL_TIME = new DateTimeFormatterBuilder()
            .append(DateTimeFormatter.ISO_LOCAL_DATE)
            .optionalStart()
            .appendLiteral('T')
            .append(DateTimeFormatter.ISO_TIME)
            .toFormatter();

would be cleaner

[cowtowncoder]

@cbornet we are always open for further improvement PRs!