No completions on package symbols

Author: rochala

compiler/src/dotty/tools/dotc/interactive/Completion.scala

@@ -245,9 +245,7 @@ object Completion:
       case tpd.Select(qual @ tpd.This(_), _) :: _ if qual.span.isSynthetic      => completer.scopeCompletions.names
       case StringContextApplication(qual) =>
         completer.scopeCompletions.names ++ completer.selectionCompletions(qual)
-      case tpd.Select(qual, _) :: _               if qual.typeOpt.hasSimpleKind =>
-        completer.selectionCompletions(qual)
-      case tpd.Select(qual, _) :: _                                             => Map.empty
+      case tpd.Select(qual, _) :: _                                             => completer.selectionCompletions(qual)
       case (tree: tpd.ImportOrExport) :: _                                      => completer.directMemberCompletions(tree.expr)
       case _                                                                    => completer.scopeCompletions.names
 
@@ -478,17 +476,16 @@ object Completion:
     def selectionCompletions(qual: tpd.Tree)(using Context): CompletionMap =
       val adjustedQual = widenQualifier(qual)
 
-      val implicitConversionMembers = implicitConversionMemberCompletions(adjustedQual)
-      val extensionMembers = extensionCompletions(adjustedQual)
-      val directMembers = directMemberCompletions(adjustedQual)
-      val namedTupleMembers = namedTupleCompletions(adjustedQual)
-
-      List(
-        implicitConversionMembers,
-        extensionMembers,
-        directMembers,
-        namedTupleMembers
-      ).reduce(_ ++ _)
+      if qual.symbol.is(Package) then
+        directMemberCompletions(adjustedQual)
+      else if qual.typeOpt.hasSimpleKind then
+        implicitConversionMemberCompletions(adjustedQual) ++
+        extensionCompletions(adjustedQual) ++
+        directMemberCompletions(adjustedQual) ++
+        namedTupleCompletions(adjustedQual)
+      else
+        Map.empty
+
 
     /** Completions for members of `qual`'s type.
      *  These include inherited definitions but not members added by extensions or implicit conversions

presentation-compiler/test/dotty/tools/pc/tests/completion/CompletionSuite.scala

@@ -2257,3 +2257,21 @@ class CompletionSuite extends BaseCompletionSuite:
         |""".stripMargin,
       ""
     )
+
+  @Test def `no-extension-completion-on-packages` =
+    check(
+      """object M:
+        |  scala.runt@@
+        |""".stripMargin,
+      """runtime scala
+        |PartialFunction scala""".stripMargin // those are the actual members of scala
+    )
+
+  @Test def `no-extension-completions-on-package-objects` =
+    check(
+      """package object magic { def test: Int = ??? }
+        |object M:
+        |  magic.@@
+        |""".stripMargin,
+      "test: Int"
+    )