package xyz.driver.sbt
import com.lucidchart.sbt.scalafmt.ScalafmtCorePlugin.autoImport.{scalafmtConfig, _}
import com.lucidchart.sbt.scalafmt.ScalafmtPlugin
import org.scalastyle.sbt.ScalastylePlugin
import org.scalastyle.sbt.ScalastylePlugin.autoImport.{scalastyle, scalastyleConfig}
import sbt.Keys._
import sbt._
import scala.collection.JavaConverters._
/** Enforces common formatting and catches compiler warnings. */
object Linting extends AutoPlugin {
override def requires = ScalafmtPlugin && ScalastylePlugin
override def trigger = allRequirements
lazy val formatSettings: Seq[Def.Setting[_]] = Seq(
scalafmtConfig := {
val packaged = getClass.getClassLoader.getResourceAsStream("scalafmt.conf")
val out = file(".scalafmt.conf")
IO.write(out, IO.readBytes(packaged))
out
},
scalafmtTestOnCompile in Test := true
)
lazy val scalastyleSettings: Seq[Def.Setting[_]] = Seq(
scalastyleConfig := {
val stream = getClass.getClassLoader.getResourceAsStream("scalastyle-config.xml")
val out = file(".scalastyle-config.xml")
IO.write(out, IO.readBytes(stream))
out
},
test in Test := (test in Test).dependsOn((scalastyle in Test).toTask("")).value
)
lazy val scalacSettings: Seq[Def.Setting[_]] = Seq(
scalacOptions in Compile ++= Seq(
"-language:higherKinds",
"-language:implicitConversions",
"-language:postfixOps",
"-language:reflectiveCalls", // TODO this should be discouraged
"-unchecked",
"-deprecation",
"-feature",
"-encoding",
"utf8",
"-Xlint:_,-unused,-missing-interpolator",
"-Ywarn-numeric-widen",
"-Ywarn-dead-code",
"-Ywarn-unused:_,-explicits,-implicits"
),
// Currently, scalac does not provide a way to fine-tune the treating of
// warnings as errors. Either all are considered errors
// (with -Xfatal-warnings), or none are. This hack analyzes the compiler's
// output and treats all warnings as errors, except for deprecations.
compile in Compile := {
val log = streams.value.log
val compiled = (compile in Compile).value
val problems = compiled.readSourceInfos().getAllSourceInfos.asScala.flatMap {
case (_, info) => info.getReportedProblems
}
var deprecationsOnly = true
problems.foreach { problem =>
if (!problem.message().contains("is deprecated")) {
deprecationsOnly = false
log.error(s"[fatal warning] ${problem.message()}")
}
}
if (!deprecationsOnly)
throw new FatalWarningsException("Fatal warnings: some warnings other than deprecations were found.")
compiled
}
)
lazy val lintSettings = formatSettings ++ scalastyleSettings ++ scalacSettings
override def projectSettings: Seq[Def.Setting[_]] = inConfig(Compile)(lintSettings) ++ inConfig(Test)(lintSettings)
}
case class FatalWarningsException(message: String) extends Exception(message)