Handle missing bsp info better

metals/src/main/scala/scala/meta/internal/metals/BuildServerConnection.scala

@@ -94,6 +94,20 @@ class BuildServerConnection private (
 
   def isAmmonite: Boolean = name == Ammonite.name
 
+  def supportsLanguage(id: String): Boolean =
+    Option(capabilities.getCompileProvider())
+      .exists(_.getLanguageIds().contains(id)) ||
+      Option(capabilities.getDebugProvider())
+        .exists(_.getLanguageIds().contains(id)) ||
+      Option(capabilities.getRunProvider())
+        .exists(_.getLanguageIds().contains(id)) ||
+      Option(capabilities.getTestProvider())
+        .exists(_.getLanguageIds().contains(id))
+
+  def supportsScala: Boolean = supportsLanguage("scala")
+
+  def supportsJava: Boolean = supportsLanguage("java")
+
   def isDebuggingProvider: Boolean =
     Option(capabilities.getDebugProvider())
       .exists(_.getLanguageIds().contains("scala"))
@@ -186,13 +200,38 @@ class BuildServerConnection private (
   def mainClasses(
       params: ScalaMainClassesParams
   ): Future[ScalaMainClassesResult] = {
-    register(server => server.buildTargetScalaMainClasses(params)).asScala
+    val resultOnUnsupported = new ScalaMainClassesResult(Collections.emptyList)
+    if (supportsScala) {
+      val onFail = Some(
+        (
+          resultOnUnsupported,
+          "Scala main classes not supported by server",
+        )
+      )
+      register(
+        server => server.buildTargetScalaMainClasses(params),
+        onFail,
+      ).asScala
+    } else Future.successful(resultOnUnsupported)
+
   }
 
   def testClasses(
       params: ScalaTestClassesParams
   ): Future[ScalaTestClassesResult] = {
-    register(server => server.buildTargetScalaTestClasses(params)).asScala
+    val resultOnUnsupported = new ScalaTestClassesResult(Collections.emptyList)
+    if (supportsScala) {
+      val onFail = Some(
+        (
+          resultOnUnsupported,
+          "Scala test classes not supported by server",
+        )
+      )
+      register(
+        server => server.buildTargetScalaTestClasses(params),
+        onFail,
+      ).asScala
+    } else Future.successful(resultOnUnsupported)
   }
 
   def startDebugSession(
@@ -240,13 +279,18 @@ class BuildServerConnection private (
     )
     if (isSbt || isAmmonite) Future.successful(resultOnJavacOptionsUnsupported)
     else {
-      val onFail = Some(
-        (
-          resultOnJavacOptionsUnsupported,
-          "Java targets not supported by server",
+      if (supportsJava) {
+        val onFail = Some(
+          (
+            resultOnJavacOptionsUnsupported,
+            "Java targets not supported by server",
+          )
         )
-      )
-      register(server => server.buildTargetJavacOptions(params), onFail).asScala
+        register(
+          server => server.buildTargetJavacOptions(params),
+          onFail,
+        ).asScala
+      } else Future.successful(resultOnJavacOptionsUnsupported)
     }
   }
 
@@ -256,10 +300,18 @@ class BuildServerConnection private (
     val resultOnScalaOptionsUnsupported = new ScalacOptionsResult(
       List.empty[ScalacOptionsItem].asJava
     )
-    val onFail = Some(
-      (resultOnScalaOptionsUnsupported, "Scala targets not supported by server")
-    )
-    register(server => server.buildTargetScalacOptions(params), onFail).asScala
+    if (supportsScala) {
+      val onFail = Some(
+        (
+          resultOnScalaOptionsUnsupported,
+          "Scala targets not supported by server",
+        )
+      )
+      register(
+        server => server.buildTargetScalacOptions(params),
+        onFail,
+      ).asScala
+    } else Future.successful(resultOnScalaOptionsUnsupported)
   }
 
   def buildTargetSources(params: SourcesParams): Future[SourcesResult] = {

metals/src/main/scala/scala/meta/internal/metals/BuildTargetInfo.scala

@@ -14,7 +14,7 @@ class BuildTargetInfo(buildTargets: BuildTargets) {
 
   def buildTargetDetails(targetName: String, uri: String): String = {
     buildTargets.all
-      .find(_.getDisplayName == targetName)
+      .find(_.getName == targetName)
       .orElse(buildTargets.all.find(_.getId.getUri.toString == uri))
       .map(target => buildTargetDetail(target.getId()))
       .getOrElse(s"Build target $targetName not found")
@@ -32,7 +32,7 @@ class BuildTargetInfo(buildTargets: BuildTargets) {
 
     commonInfo.foreach(info => {
       output += "Target"
-      output += s"  ${info.getDisplayName}"
+      output += s"  ${info.getName}"
 
       if (!info.getTags.isEmpty)
         output ++= getSection("Tags", info.getTags.asScala.toList)
@@ -91,7 +91,10 @@ class BuildTargetInfo(buildTargets: BuildTargets) {
         "Scala Binary Version",
         List(info.scalaBinaryVersion),
       )
-      output ++= getSection("Scala Platform", List(info.scalaPlatform))
+      output ++= getSection(
+        "Scala Platform",
+        List(info.scalaPlatform.toString()),
+      )
       info.jvmVersion.foreach(jvmVersion =>
         output ++= getSection("JVM Version", List(jvmVersion))
       )
@@ -136,18 +139,19 @@ class BuildTargetInfo(buildTargets: BuildTargets) {
 
   private def getSection(
       sectionName: String,
-      sectionText: List[_],
+      sectionText: List[String],
   ): List[String] =
     "" :: sectionName :: {
       if (sectionText.isEmpty) List("  NONE")
-      else sectionText.map(text => s"  $text")
+      else
+        sectionText.map(text => s"  ${if (text.isEmpty) "[BLANK]" else text}")
     }
 
   private def translateCapability(
       capability: String,
       hasCapability: Boolean,
   ): String =
-    if (hasCapability) s"  $capability" else s"  $capability <- NOT SUPPORTED"
+    if (hasCapability) capability else s"$capability <- NOT SUPPORTED"
 
   private def jarHasSource(jarName: String): Boolean = {
     val sourceJarName = jarName.replace(".jar", "-sources.jar")
@@ -194,15 +198,15 @@ class BuildTargetInfo(buildTargets: BuildTargets) {
         )
       )
     } else
-      List("  NONE")
+      List("NONE")
   }
 
   private def getDependencies(target: BuildTarget): List[String] = {
     target.getDependencies.asScala
       .map(f =>
         buildTargets
           .info(f)
-          .map(_.getDisplayName())
+          .map(_.getName())
           .getOrElse("Unknown target")
       )
       .toList
@@ -213,7 +217,7 @@ class BuildTargetInfo(buildTargets: BuildTargets) {
       .filter(dependentTarget =>
         dependentTarget.getDependencies.contains(target.getId())
       )
-      .map(_.getDisplayName())
+      .map(_.getName())
       .toList
   }
 

metals/src/main/scala/scala/meta/internal/metals/JavaTarget.scala

@@ -16,7 +16,7 @@ case class JavaTarget(
     javac: JavacOptionsItem,
     bspConnection: Option[BuildServerConnection],
 ) {
-  def displayName: String = info.getDisplayName()
+  def displayName: String = info.getName
 
   def dataKind: String = info.dataKind
 

metals/src/main/scala/scala/meta/internal/metals/MetalsEnrichments.scala

@@ -88,6 +88,8 @@ object MetalsEnrichments
 
     def isSbtBuild: Boolean = dataKind == "sbt"
 
+    def isScalaBuild: Boolean = dataKind == "scala"
+
     def baseDirectory: String =
       Option(buildTarget.getBaseDirectory()).getOrElse("")
 
@@ -96,7 +98,11 @@ object MetalsEnrichments
     def asScalaBuildTarget: Option[b.ScalaBuildTarget] = {
       asSbtBuildTarget
         .map(_.getScalaBuildTarget)
-        .orElse(decodeJson(buildTarget.getData, classOf[b.ScalaBuildTarget]))
+        .orElse(
+          if (isScalaBuild)
+            decodeJson(buildTarget.getData, classOf[b.ScalaBuildTarget])
+          else None
+        )
     }
 
     def asSbtBuildTarget: Option[b.SbtBuildTarget] = {
@@ -105,6 +111,22 @@ object MetalsEnrichments
       else
         None
     }
+
+    def getName(): String = {
+      if (buildTarget.getDisplayName == null) {
+        val name =
+          if (buildTarget.getBaseDirectory() != null)
+            buildTarget
+              .getId()
+              .getUri()
+              .stripPrefix(buildTarget.getBaseDirectory())
+          else
+            buildTarget.getId().getUri()
+
+        name.replaceAll("[^a-zA-Z0-9]+", "-")
+      } else
+        buildTarget.getDisplayName
+    }
   }
 
   implicit class XtensionTaskStart(task: b.TaskStartParams) {

metals/src/main/scala/scala/meta/internal/metals/ScalaTarget.scala

@@ -52,7 +52,7 @@ case class ScalaTarget(
     }
   }
 
-  def displayName: String = info.getDisplayName()
+  def displayName: String = info.getName
 
   def dataKind: String = info.dataKind
 

metals/src/main/scala/scala/meta/internal/metals/TargetData.scala

@@ -141,8 +141,10 @@ final class TargetData {
   }
 
   def targetClassDirectories(id: BuildTargetIdentifier): List[String] = {
-    val scalacData = scalaTarget(id).map(_.scalac.getClassDirectory).toList
-    val javacData = javaTarget(id).map(_.javac.getClassDirectory).toList
+    val scalacData =
+      scalaTarget(id).map(_.scalac.getClassDirectory).filter(_.nonEmpty).toList
+    val javacData =
+      javaTarget(id).map(_.javac.getClassDirectory).filter(_.nonEmpty).toList
     (scalacData ++ javacData).distinct
   }
 

metals/src/main/scala/scala/meta/internal/metals/doctor/Doctor.scala

@@ -532,7 +532,7 @@ final class Doctor(
       javaTarget.displayName,
       gotoBuildTargetCommand(workspace, javaTarget.displayName),
       javaTarget.dataKind,
-      javaTarget.baseDirectory,
+      Option(javaTarget.baseDirectory),
       "Java",
       compilationStatus,
       diagnosticsStatus,
@@ -612,7 +612,7 @@ final class Doctor(
       scalaTarget.displayName,
       gotoBuildTargetCommand(workspace, scalaTarget.displayName),
       scalaTarget.dataKind,
-      scalaTarget.baseDirectory,
+      Option(scalaTarget.baseDirectory),
       targetType,
       compilationStatus,
       diagnosticsStatus,

metals/src/main/scala/scala/meta/internal/metals/doctor/DoctorResults.scala

@@ -66,7 +66,7 @@ final case class DoctorTargetInfo(
     name: String,
     gotoCommand: String,
     dataKind: String,
-    baseDirectory: String,
+    baseDirectory: Option[String],
     targetType: String,
     compilationStatus: DoctorStatus,
     diagnosticsStatus: DoctorStatus,

metals/src/main/scala/scala/meta/internal/tvp/MetalsTreeViewProvider.scala

@@ -293,7 +293,7 @@ class FolderTreeViewProvider(
     _.getId(),
     _.getUri(),
     uri => new BuildTargetIdentifier(uri),
-    _.getDisplayName(),
+    _.getName(),
     _.baseDirectory,
     { () =>
       buildTargets.all.filter(target =>
@@ -447,7 +447,7 @@ class FolderTreeViewProvider(
     } yield TreeViewNode(
       TreeViewProvider.Compile,
       id.getUri,
-      s"${info.getDisplayName()} - ${compilation.timer.toStringSeconds} (${compilation.progressPercentage}%)",
+      s"${info.getName()} - ${compilation.timer.toStringSeconds} (${compilation.progressPercentage}%)",
       icon = "compile",
     )
   }

tests/unit/src/main/scala/bill/Bill.scala

@@ -140,6 +140,7 @@ object Bill {
       )
       result.setDisplayName("id")
       result.setData(scalaTarget)
+      result.setDataKind("scala")
       result
     }
     val reporter = new StoreReporter

tests/unit/src/main/scala/tests/MetalsTestEnrichments.scala

@@ -108,6 +108,7 @@ object MetalsTestEnrichments {
       val gson = new Gson
       val data = gson.toJsonTree(scalaTarget)
       buildTarget.setData(data)
+      buildTarget.setDataKind("scala")
       val result = new WorkspaceBuildTargetsResult(List(buildTarget).asJava)
       val data0 = new m.internal.metals.TargetData
       data0.addWorkspaceBuildTargets(result)