scalafmt lint

[carlosms]

Partially replaces #74, see #74 (comment).

Adds a new make lint-scala command that uses scalafmt. Travis uses this new command to replace Scalastyle.

[bzz]

Thank you @carlosms for breaking the changes down to smaller PRs!

As expected, CI now fails on lint.

[error] /home/travis/build/src-d/gemini/src/main/scala/tech/sourced/gemini/ReportApp.scala has changes after scalafmt
[error] /home/travis/build/src-d/gemini/src/main/scala/tech/sourced/gemini/QueryApp.scala has changes after scalafmt
[error] /home/travis/build/src-d/gemini/src/main/scala/tech/sourced/gemini/ConnectedComponents.scala has changes after scalafmt
[error] /home/travis/build/src-d/gemini/src/main/scala/tech/sourced/gemini/HashSparkApp.scala has changes after scalafmt
[error] /home/travis/build/src-d/gemini/src/main/scala/tech/sourced/gemini/Gemini.scala has changes after scalafmt
com.lucidchart.sbt.scalafmt.ScalafmtCheckFailure: 5 Scala sources not formatted in gemini:compile

👍 for consistent autoformatting, but as for linting - I never used scalfmt for it before and am not sure yet if it would be a good idea to replace a scalastyle, which produces the meaningful violation descriptions, with something that can only report 5 Scala sources not formatted in gemini:compile.

Let me investigate a bit more and get back to you soon.

[carlosms]

@bzz if we add to build.sbt the following:
scalafmtShowDiff in (ThisBuild, scalafmt) := true

It will show the diffs, like this:

[error] /home/cmartin/code/src-d/gemini/src/main/scala/tech/sourced/gemini/QueryApp.scala has changes after scalafmt:
[error] 60c60
[error] <       val cluster = Cluster.builder()
[error] ___
[error] >       val cluster = Cluster
[error] >         .builder()
[error] 69c70
[error] <       val channel = ManagedChannelBuilder.forAddress(config.feHost, config.fePort).usePlaintext(true).build()
[error] ___
[error] >       val channel =
[error] >         ManagedChannelBuilder.forAddress(config.feHost, config.fePort).usePlaintext(true).build()
[error] /home/cmartin/code/src-d/gemini/src/main/scala/tech/sourced/gemini/Gemini.scala has changes after scalafmt:
[error] 17c17
[error] < import tech.sourced.featurext.generated.service.{Feature, IdentifiersRequest, LiteralsRequest, Uast2seqRequest}
[error] ___
[error] > import tech.sourced.featurext.generated.service.{
[error] >   Feature,
[error] >   IdentifiersRequest,
[error] >   LiteralsRequest,
[error] >   Uast2seqRequest
[error] > }

Let me know if that's a good enough solution and I'll push the change.

[bzz]

Ok, there is a relevant discussion about applying http://docs.scala-lang.org/style/ with scalafmt and seems like people manage to adjust it quite well - please, give me some more time to experiment with it.

Meanwhile +1 for adding a flag to linter that reports violations better.

[carlosms]

Change pushed. You can see the new output here.