add test cases for #3455 #3469

Author: liufengyun

compiler/src/dotty/tools/dotc/transform/patmat/Space.scala

@@ -584,10 +584,9 @@ class SpaceEngine(implicit ctx: Context) extends SpaceLogic {
     // precondition: `tp1` should have the shape `path.Child`, thus `ThisType` is always covariant
     val thisTypeMap = new TypeMap {
       def apply(t: Type): Type = t match {
-        case tp @ ThisType(tref) if !tref.symbol.isStaticOwner && !tref.symbol.is(Module)  =>
-          // TODO: stackoverflow here
-          // newTypeVar(TypeBounds.upper(mapOver(tp.underlying)))
-          newTypeVar(TypeBounds.upper(mapOver(tref & tref.classSymbol.asClass.givenSelfType)))
+        case tp @ ThisType(tref) if !tref.symbol.isStaticOwner  =>
+          if (tref.symbol.is(Module)) mapOver(tref)
+          else newTypeVar(TypeBounds.upper(tp.underlying))
         case _ =>
           mapOver(t)
       }
@@ -633,7 +632,7 @@ class SpaceEngine(implicit ctx: Context) extends SpaceLogic {
     else {
       val protoTp2 = typeParamMap(tp2)
       if (protoTp1 <:< protoTp2) {
-        isFullyDefined(protoTp1 & protoTp2, force)
+        isFullyDefined(AndType(protoTp1, protoTp2), force)
         instUndetMap(protoTp1)
       }
       else {

tests/patmat/3455.check

@@ -0,0 +1 @@
+11: Pattern Match Exhaustivity: Decimal

tests/patmat/3455.scala

@@ -0,0 +1,14 @@
+trait AxisCompanion {
+   sealed trait Format
+   object Format {
+      case object Decimal extends Format
+      case object Integer extends Format
+   }
+}
+object Axis extends AxisCompanion
+class Axis {
+   import Axis._
+   def test( f: Format ) = f match {
+      case Format.Integer => "Int"
+   }
+}

tests/patmat/3469.scala

@@ -0,0 +1,9 @@
+object O {
+  sealed trait Trait[+A] { type T }
+  case class CaseClass[+A](a: A) extends Trait[A] { type T = Nothing }
+
+  def id[TT, A](v: Trait[A] { type T = TT }): Trait[A] { type T = TT } =
+    v match {
+      case CaseClass(a) => CaseClass(a)
+    }
+}