Scala: detect unused imports

[jduan]

AFAICT, "spotlessCheck" doesn't fail if there are unused imports for Scala code. Can this be supported?

[nedtwigg]

I believe ScalaFmt does not support this: scalameta/scalafmt#722

ScalaFix does support removing unused imports, and there is an abandoned PR which adds ScalaFix support for Spotless: #591.

[jduan]

Thank you for your quick response. I'll wait for #591 then. I don't have the chops to add ScalaFix support.