Extension method groupping fix. CRs from PR #10306

Author: pikinier20

scala3doc/src/dotty/dokka/model/api/api.scala

@@ -49,7 +49,7 @@ enum Modifier(val name: String, val prefix: Boolean):
   case Opaque extends Modifier("opaque", true)
   case Open extends Modifier("open", true)
 
-case class ExtensionTarget(name: String, signature: Signature, dri: DRI)
+case class ExtensionTarget(name: String, signature: Signature, dri: DRI, position: Long)
 case class ImplicitConversion(from: DRI, to: DRI)
 trait ImplicitConversionProvider { def conversion: Option[ImplicitConversion] }
 trait Classlike

scala3doc/src/dotty/dokka/tasty/ClassLikeSupport.scala

@@ -109,7 +109,12 @@ trait ClassLikeSupport:
   private def parseMember(s: Tree): Option[Member] = processTreeOpt(s)(s match
       case dd: DefDef if !dd.symbol.isHiddenByVisibility && !dd.symbol.isSyntheticFunc && dd.symbol.isExtensionMethod =>
         dd.symbol.extendedSymbol.map { extSym =>
-          val target = ExtensionTarget(extSym.symbol.normalizedName, extSym.tpt.dokkaType.asSignature, extSym.tpt.symbol.dri)
+          val target = ExtensionTarget(
+            extSym.symbol.normalizedName, 
+            extSym.tpt.dokkaType.asSignature, 
+            extSym.tpt.symbol.dri, 
+            extSym.symbol.pos.start
+          )
           parseMethod(dd.symbol, kind = Kind.Extension(target))
         }
       // TODO check given methods?

scala3doc/src/dotty/dokka/tasty/TastyParser.scala

@@ -168,7 +168,7 @@ case class TastyParser(qctx: QuoteContext, inspector: DokkaBaseTastyInspector, c
 
   private def errorMsg[T](a: Any, m: => String, e: Throwable): Option[T] =
     val msg = try m catch case e: Throwable => a.toString
-    println(s"ERROR: tree is faling: msg")
+    println(s"ERROR: tree is faling: $msg")
     e.printStackTrace()
     throw e
 

scala3doc/src/dotty/dokka/transformers/ImplicitMembersExtensionTransformer.scala

@@ -17,13 +17,13 @@ class ImplicitMembersExtensionTransformer(ctx: DokkaContext) extends Documentabl
 
     def expandMember(outerMembers: Seq[Member])(c: Member): Member =
       val companion = c match
-        case classlike: DClass => ClasslikeExtension.getFrom(classlike).flatMap(_.companion).flatMap(classlikeMap.get)
+        case classlike: DClass => ClasslikeExtension.getFrom(classlike).flatMap(_.companion).map(classlikeMap)
         case _ => None
 
       val allParents = c.parents.flatMap(p => classlikeMap.get(p.dri))
 
       val parentCompanions = allParents.flatMap {
-          case cls: DClasslike => ClasslikeExtension.getFrom(cls).flatMap(_.companion).flatMap(classlikeMap.get)
+          case cls: DClasslike => ClasslikeExtension.getFrom(cls).flatMap(_.companion).map(classlikeMap)
           case _ => None
       }
 
@@ -34,7 +34,7 @@ class ImplicitMembersExtensionTransformer(ctx: DokkaContext) extends Documentabl
 
       val MyDri = c.getDri
       def collectApplicableMembers(source: Member): Seq[Member] = source.allMembers.flatMap {
-        case m @ Member(_, _, _, Kind.Extension(ExtensionTarget(_, _, MyDri)), Origin.DefinedWithin) =>
+        case m @ Member(_, _, _, Kind.Extension(ExtensionTarget(_, _, MyDri, _)), Origin.DefinedWithin) =>
           Seq(m.withOrigin(Origin.ExtensionFrom(source.name, source.dri)).withKind(Kind.Def))
         case m @ Member(_, _, _, conversionProvider: ImplicitConversionProvider, Origin.DefinedWithin) =>
           conversionProvider.conversion match