Preserve copyright years

[retronym]

Rather than just writing the new header into files, it would be better to "merge" the old and new headers, taking the current year and overall format from the configured header, and the copyright year ranges from the old.

[retronym]

WIP retronym#1

[hseeberger]

I haven't looked into your code yet, but one feature I want to keep is overwriting existing headers in order to enforce a single header thought the whole project. Of course an option to allow for file specific dates is fine and maybe another one (not the default) to keep (the format of) existing headers. If you plan for the latter, too, please add another issue/PR, i.e. let's keep this focussed on optionally preserving the copyright year(s).

[retronym]

I'm all for consistent headers too. I think we can expose a new boolean setting that one can use to enable the date range merging.

[fommil]

@retronym did you ever get round to finishing this off? Sounds like something I'd be interested in too.

[FelAl]

I can finish it.

[dwijnand]

note for people subscribed here that progress was made here by way of #142.

and sbt-header is now used by the akka and akka-http projects:

• Configure sbt-header and update Lightbend copyright headers akka/akka-http#1738
• Issue 24594: Integration with sbt-headers and initial header population. akka/akka#24715.

[mkurz]

Probably related: #282