catch all exceptions in unpickler

modules/core/src/main/scala/ch/epfl/scala/debugadapter/internal/stacktrace/Scala2Unpickler.scala

@@ -13,7 +13,7 @@ class Scala2Unpickler(
     scalaVersion: ScalaVersion,
     logger: Logger,
     testMode: Boolean
-) extends ScalaUnpickler(scalaVersion) {
+) extends ScalaUnpickler(scalaVersion, testMode) {
   override protected def skipScala(method: jdi.Method): Boolean = {
     if (isLazyInitializer(method)) {
       skipLazyInitializer(method)

modules/core/src/main/scala/ch/epfl/scala/debugadapter/internal/stacktrace/Scala3Unpickler.scala

@@ -10,8 +10,6 @@ import ch.epfl.scala.debugadapter.Java8
 import ch.epfl.scala.debugadapter.Java9OrAbove
 import scala.util.Try
 import java.nio.file.Path
-import scala.util.Success
-import scala.util.Failure
 import java.util.Optional
 import ch.epfl.scala.debugadapter.ScalaVersion
 import scala.jdk.OptionConverters._
@@ -20,8 +18,9 @@ class Scala3UnpicklerBridge(
     scalaVersion: ScalaVersion,
     bridge: Any,
     skipMethod: Method,
-    formatMethod: Method
-) extends ScalaUnpickler(scalaVersion) {
+    formatMethod: Method,
+    testMode: Boolean
+) extends ScalaUnpickler(scalaVersion, testMode) {
   override protected def skipScala(method: jdi.Method): Boolean = {
     try skipMethod.invoke(bridge, method).asInstanceOf[Boolean]
     catch {
@@ -47,7 +46,7 @@ object Scala3UnpicklerBridge {
       logger: Logger,
       testMode: Boolean
   ): Try[Scala3UnpicklerBridge] = {
-    try {
+    Try {
       val className = "ch.epfl.scala.debugadapter.internal.stacktrace.Scala3Unpickler"
       val cls = classLoader.loadClass(className)
       val ctr = cls.getConstructor(classOf[Array[Path]], classOf[Consumer[String]], classOf[Boolean])
@@ -68,9 +67,7 @@ object Scala3UnpicklerBridge {
       val skipMethod = cls.getMethods.find(m => m.getName == "skipMethod").get
       val formatMethod = cls.getMethods.find(m => m.getName == "formatMethod").get
 
-      Success(new Scala3UnpicklerBridge(debuggee.scalaVersion, bridge, skipMethod, formatMethod))
-    } catch {
-      case cause: Throwable => Failure(cause)
+      new Scala3UnpicklerBridge(debuggee.scalaVersion, bridge, skipMethod, formatMethod, testMode)
     }
   }
 }

modules/core/src/main/scala/ch/epfl/scala/debugadapter/internal/stacktrace/ScalaUnpickler.scala

@@ -11,11 +11,16 @@ import com.sun.jdi.Method
 import com.sun.jdi.ReferenceType
 
 import scala.jdk.CollectionConverters.*
+import scala.util.control.NonFatal
 
-abstract class ScalaUnpickler(scalaVersion: ScalaVersion) extends StepFilter {
+abstract class ScalaUnpickler(scalaVersion: ScalaVersion, testMode: Boolean) extends StepFilter {
   protected def skipScala(method: Method): Boolean
   protected def formatScala(method: Method): Option[String] = Some(formatJava(method))
 
+  private def throwOrWarn(exception: Throwable): Unit =
+    if (testMode) throw exception
+    else exception.getMessage
+
   override def shouldSkipOver(method: Method): Boolean = {
     if (method.isBridge) true
     else if (isDynamicClass(method.declaringType)) true
@@ -31,7 +36,11 @@ abstract class ScalaUnpickler(scalaVersion: ScalaVersion) extends StepFilter {
     else if (scalaVersion.isScala2 && isNestedClass(method.declaringType)) false
     else if (isDefaultValue(method)) false
     else if (isTraitInitializer(method)) skipTraitInitializer(method)
-    else skipScala(method)
+    else
+      try skipScala(method)
+      catch {
+        case NonFatal(e) => throwOrWarn(e); false
+      }
   }
 
   def format(method: Method): Option[String] = {
@@ -49,7 +58,11 @@ abstract class ScalaUnpickler(scalaVersion: ScalaVersion) extends StepFilter {
     else if (isLocalClass(method.declaringType)) Some(formatJava(method))
     else if (scalaVersion.isScala2 && isNestedClass(method.declaringType)) Some(formatJava(method))
     else if (isDefaultValue(method)) Some(formatJava(method))
-    else formatScala(method)
+    else
+      try formatScala(method)
+      catch {
+        case NonFatal(e) => throwOrWarn(e); Some(formatJava(method))
+      }
   }
 
   private def formatJava(method: Method): String = {
@@ -150,10 +163,11 @@ object ScalaUnpickler {
             .tryLoad(debuggee, classLoader, logger, testMode)
             .warnFailure(logger, s"Cannot load step filter for Scala ${debuggee.scalaVersion}")
         }
-        .getOrElse(fallback(debuggee.scalaVersion))
+        .getOrElse(fallback(debuggee.scalaVersion, testMode))
   }
 
-  private def fallback(scalaVersion: ScalaVersion): ScalaUnpickler = new ScalaUnpickler(scalaVersion) {
-    override protected def skipScala(method: Method): Boolean = false
-  }
+  private def fallback(scalaVersion: ScalaVersion, testMode: Boolean): ScalaUnpickler =
+    new ScalaUnpickler(scalaVersion, testMode) {
+      override protected def skipScala(method: Method): Boolean = false
+    }
 }

modules/tests/src/main/scala/ch/epfl/scala/debugadapter/testfmk/FakeJdiMethod.scala

@@ -36,11 +36,11 @@ final case class FakeJdiMethod(
 
   override def compareTo(o: Method): Int = ???
 
-  override def returnTypeName(): String = ???
+  override def returnTypeName(): String = returnType.name
 
   override def argumentTypeNames(): ju.List[String] = ???
 
-  override def argumentTypes(): ju.List[Type] = ???
+  override def argumentTypes(): ju.List[Type] = arguments.asScala.map(_.`type`).asJava
 
   override def isAbstract(): Boolean = ???
 

modules/unpickler/src/main/scala/ch/epfl/scala/debugadapter/internal/jdi/Method.scala

@@ -10,22 +10,23 @@ class Method(val obj: Any) extends JavaReflection(obj, "com.sun.jdi.Method"):
     ReferenceType(invokeMethod("declaringType"))
 
   def arguments: Seq[LocalVariable] =
-    invokeMethod[java.util.List[Object]]("arguments").asScala.toSeq
-      .map(LocalVariable.apply(_))
+    invokeMethod[java.util.List[Object]]("arguments").asScala.toSeq.map(LocalVariable.apply(_))
+
+  def argumentTypes: Seq[Type] =
+    invokeMethod[java.util.List[Object]]("argumentTypes").asScala.toSeq.map(Type.apply(_))
 
   def returnType: Option[Type] =
     try Some(Type(invokeMethod("returnType")))
     catch
       case e: InvocationTargetException if e.getCause.getClass.getName == "com.sun.jdi.ClassNotLoadedException" =>
         None
 
-  def isExtensionMethod: Boolean =
-    name.endsWith("$extension")
+  def returnTypeName: String = invokeMethod("returnTypeName")
+
+  def isExtensionMethod: Boolean = name.endsWith("$extension")
 
-  def isTraitInitializer: Boolean =
-    name == "$init$"
+  def isTraitInitializer: Boolean = name == "$init$"
 
-  def isClassInitializer: Boolean =
-    name == "<init>"
+  def isClassInitializer: Boolean = name == "<init>"
 
   override def toString: String = invokeMethod("toString")

modules/unpickler/src/main/scala/ch/epfl/scala/debugadapter/internal/stacktrace/Scala3Unpickler.scala

@@ -41,46 +41,33 @@ class Scala3Unpickler(
     else exception.getMessage
 
   def skipMethod(obj: Any): Boolean =
-    findSymbolImpl(obj) match
-      case Failure(exception) => throwOrWarn(exception); false
-      case Success(Some(symbol)) => skip(symbol)
-      case Success(None) => true
+    findSymbol(obj).forall(skip)
 
   def formatMethod(obj: Any): Optional[String] =
-    val method = jdi.Method(obj)
-    findSymbol(obj).map { t =>
-      val notMethodType = t.declaredType match {
-        case _: MethodType => false
-        case _: PolyType => false
-        case _ => true
-      }
-      val optionalString = if (notMethodType) ": " else ""
-      s"${formatSymbol(t)}${optionalString}${formatType(t.declaredType)}"
-    }.asJava
+    findSymbol(obj) match
+      case None => Optional.empty
+      case Some(symbol) =>
+        val sep = if !symbol.declaredType.isInstanceOf[MethodicType] then ": " else ""
+        Optional.of(s"${formatSymbol(symbol)}$sep${formatType(symbol.declaredType)}")
 
   private[stacktrace] def findSymbol(obj: Any): Option[TermSymbol] =
-    findSymbolImpl(obj).get
-
-  private def findSymbolImpl(obj: Any): Try[Option[TermSymbol]] =
     val method = jdi.Method(obj)
     val fqcn = method.declaringType.name
     findDeclaringType(fqcn, method.isExtensionMethod) match
       case None =>
-        Failure(Exception(s"Cannot find Scala symbol of $fqcn"))
+        throw new Exception(s"Cannot find Scala symbol of $fqcn")
       case Some(declaringType) =>
         val matchingSymbols =
           declaringType.declarations
             .collect { case sym: TermSymbol if sym.isTerm => sym }
             .filter(matchSymbol(method, _))
 
         if matchingSymbols.size > 1 then
-          val builder = new java.lang.StringBuilder
-          builder.append(
-            s"Found ${matchingSymbols.size} matching symbols for $method:"
-          )
-          matchingSymbols.foreach(sym => builder.append(s"\n$sym"))
-          Failure(Exception(builder.toString))
-        else Success(matchingSymbols.headOption)
+          val message =
+            s"Found ${matchingSymbols.size} matching symbols for $method:" +
+              matchingSymbols.mkString("\n")
+          throw new Exception(message)
+        else matchingSymbols.headOption
 
   def formatType(t: Type): String =
     t match