Warning configuration DSL

[laughedelic]

Hi! I have defined this little DSL for warnings configuration and thought of sharing it. It's pretty hard to remember all available filters, their short names, which actions have configurable verbosity, etc. and then piece them correctly together into a single string. With a DSL it's much easier to discover what's available via auto-complete, see full names and have a clear, readable configuration definition.

sealed trait WarningAction

case object silent extends WarningAction
case object error extends WarningAction

sealed trait WarningActionWithVerbosity extends WarningAction { action =>

  def summary: WarningAction = new WarningAction {
    override def toString = s"${action}-summary"
  }

  def verbose: WarningAction = new WarningAction {
    override def toString = s"${action}-verbose"
  }

}

case object warning extends WarningActionWithVerbosity
case object info extends WarningActionWithVerbosity

sealed class WarningFilter(val asString: String) {
  override def toString = asString

  def &(that: WarningFilter): WarningFilter = new WarningFilter(
    Seq(this.asString, that.asString).mkString("&")
  )

}

case object any extends WarningFilter("any")
case class cat(cat: String) extends WarningFilter(s"cat=${cat}")
case class msg(regex: String) extends WarningFilter(s"msg=${regex}")
case class src(regex: String) extends WarningFilter(s"src=${regex}")

case class origin(segments: String*)
    extends WarningFilter(s"origin=${segments.mkString(raw"\.")}")

case class WarningConfig(val rules: (WarningFilter, WarningAction)*) {

  override def toString = {
    val conf = rules.toSeq
      .map { case (filter, action) => Seq(filter, action).mkString(":") }
      .mkString(",")
    s"-Wconf:${conf}"
  }

  def asScalacOption =
    ScalacOption(
      option = this.toString,
      isSupported = {
        case ScalaVersion(2, 12, x) => x >= 13
        case ScalaVersion(2, 13, x) => x >= 2
        case _                      => false
      },
    )

}

Example usage:

WarningConfig(
  src("src_managed/.*") -> silent,
  cat("unused-imports") -> warning,
  (cat("deprecation") & origin("scala", ".*")) -> error,
  cat("deprecation") -> warning.verbose,
  cat("unused") -> warning.summary,
  any -> error,
)

is transformed into -Wconf:src=src_managed/.*:silent,cat=unused-imports:warning,cat=deprecation&origin=scala\..*:error,cat=deprecation:warning-verbose,cat=unused:warning-summary,any:error or with line breaks for readability:

-Wconf:
src=src_managed/.*:silent,
cat=unused-imports:warning,
cat=deprecation&origin=scala\..*:error,
cat=deprecation:warning-verbose,
cat=unused:warning-summary,
any:error

---

Would you be open to a pull request adding such DSL here? Details of the design are open for discussion, of course.

[SethTisue]

@lrytz FYI