WIP - set hint message in relatedInformation parameter in diagnostic

modules/build/src/main/scala/scala/build/ConsoleBloopBuildClient.scala

@@ -85,7 +85,7 @@ class ConsoleBloopBuildClient(
         .getOrElse((Right(path), diag))
       if (keepDiagnostics)
         diagnostics0 += updatedPath -> updatedDiag
-      ConsoleBloopBuildClient.printFileDiagnostic(logger, updatedPath, updatedDiag)
+      ConsoleBloopBuildClient.printFileDiagnostic(logger, updatedPath, updatedDiag, None)
     }
   }
 
@@ -151,19 +151,27 @@ object ConsoleBloopBuildClient {
   private val red    = Console.RED
   private val yellow = Console.YELLOW
 
-  def diagnosticPrefix(isError: Boolean): String =
-    if (isError) s"[${red}error$reset] "
-    else s"[${yellow}warn$reset] "
+  def diagnosticPrefix(severity: bsp4j.DiagnosticSeverity): String =
+    severity match {
+      case bsp4j.DiagnosticSeverity.ERROR   => s"[${red}error$reset] "
+      case bsp4j.DiagnosticSeverity.WARNING => s"[${yellow}warn$reset] "
+      case bsp4j.DiagnosticSeverity.HINT    => s"[${yellow}hint$reset] "
+    }
+
+  def diagnosticPrefix(severity: Severity): String = diagnosticPrefix(severity.toBsp4j)
 
   def printFileDiagnostic(
     logger: Logger,
     path: Either[String, os.Path],
-    diag: bsp4j.Diagnostic
+    diag: bsp4j.Diagnostic,
+    hint: Option[String]
   ): Unit = {
-    val isWarningOrError = diag.getSeverity == bsp4j.DiagnosticSeverity.ERROR ||
-      diag.getSeverity == bsp4j.DiagnosticSeverity.WARNING
-    if (isWarningOrError) {
-      val prefix = diagnosticPrefix(diag.getSeverity == bsp4j.DiagnosticSeverity.ERROR)
+    val isHint = diag.getSeverity == bsp4j.DiagnosticSeverity.HINT
+    val isWarningOrErrorOrHint = diag.getSeverity == bsp4j.DiagnosticSeverity.ERROR ||
+      diag.getSeverity == bsp4j.DiagnosticSeverity.WARNING ||
+      isHint
+    if (isWarningOrErrorOrHint) {
+      val prefix = diagnosticPrefix(diag.getSeverity)
 
       val line  = (diag.getRange.getStart.getLine + 1).toString + ":"
       val col   = (diag.getRange.getStart.getCharacter + 1).toString + ":"
@@ -199,9 +207,14 @@ object ConsoleBloopBuildClient {
       if (canPrintUnderline) {
         val len =
           math.max(1, diag.getRange.getEnd.getCharacter - diag.getRange.getStart.getCharacter)
-        logger.message(
-          prefix + " " * diag.getRange.getStart.getCharacter + "^" * len
-        )
+        if (isHint)
+          logger.message(
+            prefix + " " * (diag.getRange.getStart.getCharacter - 4) + hint.get
+          )
+        else
+          logger.message(
+            prefix + " " * diag.getRange.getStart.getCharacter + "^" * len
+          )
       }
     }
   }
@@ -215,7 +228,7 @@ object ConsoleBloopBuildClient {
     val isWarningOrError = true
     if (isWarningOrError) {
       val msgIt  = message.linesIterator
-      val prefix = diagnosticPrefix(severity == Severity.Error)
+      val prefix = diagnosticPrefix(severity)
       logger.message(prefix + (if (msgIt.hasNext) " " + msgIt.next() else ""))
       msgIt.foreach(line => logger.message(prefix + line))
 

modules/build/src/main/scala/scala/build/bsp/BspClient.scala

@@ -7,6 +7,8 @@ import java.net.URI
 import java.nio.file.Paths
 import java.util.concurrent.{ConcurrentHashMap, ExecutorService}
 
+import ch.epfl.scala.bsp4j.Location
+
 import scala.build.Position.File
 import scala.build.errors.{BuildException, CompositeBuildException, Diagnostic, Severity}
 import scala.build.postprocessing.LineConversion
@@ -187,18 +189,22 @@ class BspClient(
   )(diag: Diagnostic): Seq[os.Path] =
     diag.positions.flatMap {
       case File(Right(path), (startLine, startC), (endL, endC)) =>
-        val id = new b.TextDocumentIdentifier(path.toNIO.toUri.toASCIIString)
-        val bDiag = {
-          val startPos = new b.Position(startLine, startC)
-          val endPos   = new b.Position(endL, endC)
-          val range    = new b.Range(startPos, endPos)
+        val id       = new b.TextDocumentIdentifier(path.toNIO.toUri.toASCIIString)
+        val startPos = new b.Position(startLine, startC)
+        val endPos   = new b.Position(endL, endC)
+        val range    = new b.Range(startPos, endPos)
+        val bDiag =
           new b.Diagnostic(range, diag.message)
+
+        bDiag.setSource("scala-cli")
+        bDiag.setSeverity(diag.severity.toBsp4j)
+
+        diag.hint.foreach { hintMsg =>
+          val location = new Location(path.toNIO.toUri.toASCIIString, range)
+          val related  = new b.DiagnosticRelatedInformation(location, hintMsg)
+          bDiag.setRelatedInformation(related)
         }
-        val severity = diag.severity match {
-          case Severity.Error   => b.DiagnosticSeverity.ERROR
-          case Severity.Warning => b.DiagnosticSeverity.WARNING
-        }
-        bDiag.setSeverity(severity)
+
         val params = new b.PublishDiagnosticsParams(
           id,
           targetId,

modules/build/src/test/scala/scala/build/tests/DirectiveTests.scala

@@ -16,7 +16,7 @@ class DirectiveTests extends munit.FunSuite {
   def bloopConfigOpt = Some(BloopServer.bloopConfig)
 
   val extraRepoTmpDir = os.temp.dir(prefix = "scala-cli-tests-extra-repo-")
-  val directories = Directories.under(extraRepoTmpDir)
+  val directories     = Directories.under(extraRepoTmpDir)
 
   override def afterAll(): Unit = {
     TestInputs.tryRemoveAll(extraRepoTmpDir)
@@ -38,21 +38,21 @@ class DirectiveTests extends munit.FunSuite {
     )
     testInputs.withBuild(baseOptions, buildThreads, bloopConfigOpt) {
       (_, _, maybeBuild) =>
-        val build       = maybeBuild.orThrow
-        val dep         = build.options.classPathOptions.extraDependencies.toSeq.headOption
+        val build = maybeBuild.orThrow
+        val dep   = build.options.classPathOptions.extraDependencies.toSeq.headOption
         assert(dep.nonEmpty)
 
         val position = dep.get.positions.headOption
         assert(position.nonEmpty)
 
         val (startPos, endPos) = position.get match {
           case Position.File(_, startPos, endPos) => (startPos, endPos)
-          case _ => sys.error("cannot happen")
+          case _                                  => sys.error("cannot happen")
         }
 
-        expect(startPos == (0,15))
-        expect(endPos == (0,40))
+        expect(startPos == (0, 15))
+        expect(endPos == (0, 40))
     }
   }
 
-}
+}

modules/cli/src/main/scala/scala/cli/commands/DependencyUpdate.scala

@@ -83,12 +83,12 @@ object DependencyUpdate extends ScalaCommand[DependencyUpdateOptions] {
         val appliedDiagnostics = updateDependencies(file, sortedByLine)
         os.write.over(file, appliedDiagnostics)
         diagnostics.foreach(diagnostic =>
-          logger.message(s"Updated dependency to: ${diagnostic._2.to}")
+          logger.message(s"Updated dependency to: ${diagnostic._2.hint}")
         )
       case (Left(file), diagnostics) =>
         diagnostics.foreach {
           diagnostic =>
-            logger.message(s"Warning: Scala CLI can't update ${diagnostic._2.to} in $file")
+            logger.message(s"Warning: Scala CLI can't update ${diagnostic._2.hint} in $file")
         }
     }
   }
@@ -106,7 +106,7 @@ object DependencyUpdate extends ScalaCommand[DependencyUpdateOptions] {
         val startIndex     = startIndicies(line) + column
         val endIndex       = startIndex + diagnostic.oldDependency.render.length()
 
-        val newDependency = diagnostic.to
+        val newDependency = diagnostic.hint
         s"${fileContent.slice(0, startIndex)}$newDependency${fileContent.drop(endIndex)}"
     }
   }

modules/cli/src/main/scala/scala/cli/internal/CliLogger.scala

@@ -1,6 +1,7 @@
 package scala.cli.internal
 
 import ch.epfl.scala.{bsp4j => b}
+import ch.epfl.scala.bsp4j.Location
 import coursier.cache.CacheLogger
 import coursier.cache.loggers.{FallbackRefreshDisplay, RefreshLogger}
 import org.scalajs.logging.{Level => ScalaJsLevel, Logger => ScalaJsLogger, ScalaConsoleLogger}
@@ -28,7 +29,8 @@ class CliLogger(
         d.positions,
         d.severity,
         d.message,
-        hashMap
+        hashMap,
+        d.hint
       )
     }
   }
@@ -54,11 +56,12 @@ class CliLogger(
     positions: Seq[Position],
     severity: Severity,
     message: String,
-    contentCache: mutable.Map[os.Path, Seq[String]]
+    contentCache: mutable.Map[os.Path, Seq[String]],
+    hint: Option[String]
   ) =
     if (positions.isEmpty)
       out.println(
-        s"${ConsoleBloopBuildClient.diagnosticPrefix(Severity.Error == severity)} $message"
+        s"${ConsoleBloopBuildClient.diagnosticPrefix(severity)} $message"
       )
     else {
       val positions0 = positions.distinct
@@ -75,10 +78,17 @@ class CliLogger(
         val endPos   = new b.Position(f.endPos._1, f.endPos._2)
         val range    = new b.Range(startPos, endPos)
         val diag     = new b.Diagnostic(range, message)
-        diag.setSeverity(severity match {
-          case Severity.Error   => b.DiagnosticSeverity.ERROR
-          case Severity.Warning => b.DiagnosticSeverity.WARNING
-        })
+        diag.setSeverity(severity.toBsp4j)
+        diag.setSource("scala-cli")
+
+        for {
+          filePath <- f.path
+          hintMsg  <- hint
+        } {
+          val location = new Location(filePath.toNIO.toUri.toASCIIString, range)
+          val related  = new b.DiagnosticRelatedInformation(location, hintMsg)
+          diag.setRelatedInformation(related)
+        }
 
         for (file <- f.path) {
           val lines = contentCache.getOrElseUpdate(file, os.read(file).linesIterator.toVector)
@@ -88,7 +98,8 @@ class CliLogger(
         ConsoleBloopBuildClient.printFileDiagnostic(
           this,
           f.path,
-          diag
+          diag,
+          hint
         )
       }
 
@@ -112,7 +123,7 @@ class CliLogger(
         for (ex <- c.exceptions)
           printEx(ex, contentCache)
       case _ =>
-        printDiagnostic(ex.positions, Severity.Error, ex.getMessage(), contentCache)
+        printDiagnostic(ex.positions, Severity.Error, ex.getMessage(), contentCache, None)
     }
 
   def log(ex: BuildException): Unit =

modules/core/src/main/scala/scala/build/errors/Diagnostic.scala

@@ -6,6 +6,7 @@ trait Diagnostic {
   def message: String
   def severity: Severity
   def positions: Seq[Position]
+  def hint: Option[String] = None
 }
 
 object Diagnostic {
@@ -17,12 +18,14 @@ object Diagnostic {
   private case class ADiagnostic(
     message: String,
     severity: Severity,
-    positions: Seq[Position]
+    positions: Seq[Position],
+    override val hint: Option[String]
   ) extends Diagnostic
 
   def apply(
     message: String,
     severity: Severity,
-    positions: Seq[Position] = Nil
-  ): Diagnostic = ADiagnostic(message, severity, positions)
+    positions: Seq[Position] = Nil,
+    hint: Option[String] = None
+  ): Diagnostic = ADiagnostic(message, severity, positions, hint)
 }

modules/core/src/main/scala/scala/build/errors/Severity.scala

@@ -1,8 +1,19 @@
 package scala.build.errors
 
-sealed abstract class Severity extends Product with Serializable
+import ch.epfl.scala.bsp4j as b
+import ch.epfl.scala.bsp4j.DiagnosticSeverity
+sealed abstract class Severity extends Product with Serializable {
+  def toBsp4j: b.DiagnosticSeverity
+}
 
 object Severity {
-  case object Error   extends Severity
-  case object Warning extends Severity
+  case object Error extends Severity {
+    override def toBsp4j: DiagnosticSeverity = b.DiagnosticSeverity.ERROR
+  }
+  case object Warning extends Severity {
+    override def toBsp4j: DiagnosticSeverity = b.DiagnosticSeverity.WARNING
+  }
+  case object Hint extends Severity {
+    override def toBsp4j: DiagnosticSeverity = b.DiagnosticSeverity.HINT
+  }
 }

modules/options/src/main/scala/scala/build/actionable/ActionableDiagnostic.scala

@@ -13,14 +13,15 @@ abstract class ActionableDiagnostic {
 
   /** Provide the new content which will be replaced by actionable diagnostic
     */
-  def to: String
+  def hint: String
+
   def positions: Seq[Position]
 
   final def toDiagnostic: Diagnostic = Diagnostic(
-    message = s"""|$message
-                  |       To: $to""".stripMargin,
-    severity = Severity.Warning,
-    positions = positions
+    message = message,
+    severity = Severity.Hint,
+    positions = positions,
+    hint = Some(hint)
   )
 }
 
@@ -32,7 +33,7 @@ object ActionableDiagnostic {
     oldDependency: AnyDependency,
     newVersion: String
   ) extends ActionableDiagnostic {
-    override def to: String = oldDependency.copy(version = newVersion).render
+    override def hint: String = oldDependency.copy(version = newVersion).render
   }
 
 }