Fix #511 use declaredTypes instead of typeMembers to extract variance…

… of type parameters

izumi-reflect/izumi-reflect/src/main/scala-3/izumi/reflect/dottyreflection/Inspector.scala

@@ -70,16 +70,17 @@ abstract class Inspector(protected val shift: Int, val context: Queue[Inspector.
         inspectTypeRepr(a.underlying)
 
       case appliedType: AppliedType =>
-        appliedType.args match {
+        val tycon: TypeRepr = appliedType.tycon._dealiasSimplifiedFull
+        val args0: List[TypeRepr] = appliedType.args
+        args0 match {
           case Nil =>
-            makeNameReferenceFromType(appliedType.tycon)
+            makeNameReferenceFromType(tycon)
           case _ =>
-            val symbolVariances = appliedType.tycon.typeSymbol.typeMembers.collect {
-              case s if s.isTypeParam =>
-                extractVariance(s)
+            val symbolVariances: List[Variance] = tycon.typeSymbol.declaredTypes.collect {
+              case s if s.isTypeParam => extractVariance(s)
             }
-            val variances = if (symbolVariances.sizeCompare(appliedType.args) < 0) {
-              appliedType.tycon match {
+            val variances: List[Variance] = if (symbolVariances.sizeCompare(appliedType.args) < 0) {
+              tycon match {
                 case typeParamRef: ParamRef =>
                   typeParamRef._underlying match {
                     case TypeBounds(_, hi) =>
@@ -93,9 +94,9 @@ abstract class Inspector(protected val shift: Int, val context: Queue[Inspector.
             } else {
               symbolVariances
             }
-            val nameRef = makeNameReferenceFromType(appliedType.tycon)
-            val args = appliedType
-              .args.iterator
+            val nameRef = makeNameReferenceFromType(tycon)
+            val args = args0
+              .iterator
               .zipAll(variances, null.asInstanceOf[TypeRepr], Variance.Invariant)
               .takeWhile(_._1 != null)
               .map(next().inspectTypeParam(_, _)).toList

izumi-reflect/izumi-reflect/src/main/scala-3/izumi/reflect/dottyreflection/ReflectionUtil.scala

@@ -86,6 +86,12 @@ private[dottyreflection] trait ReflectionUtil { this: InspectorBase =>
   import ReflectionUtil.reflectiveUncheckedNonOverloadedSelectable
   import InternalContext.InternalContext
 
+  extension (symbol: Symbol) {
+    protected final def _info: TypeRepr = {
+      symbol.asInstanceOf[InternalSymbol].denot(qctx._ctx).info(qctx._ctx)
+    }
+  }
+
   extension (typeRef: TypeRef | ParamRef) {
     protected final def _underlying: TypeRepr = {
       // This works as a substitution for `TypeRef#underlying` call,
@@ -122,7 +128,8 @@ private[dottyreflection] trait ReflectionUtil { this: InspectorBase =>
     protected final def _dealiasSimplifiedFull: TypeRepr = {
 //      val res = typeRepr.dealias.simplified
       // simplified does everything below functions do, with exception of `_removeTautologicalUnions` for some reason
-      // All of these would be more useful, if not for forced type simplification on implicit macro - https://github.com/lampepfl/dotty/issues/17544
+      // All of these would be more useful, if not for forced type simplification on implicit macro
+      // - https://github.com/lampepfl/dotty/issues/17544
       val res = typeRepr.dealias._removeTautologicalIntersections._removeTautologicalUnions._simplifyMatchCase
       if (res.asInstanceOf[AnyRef] eq typeRepr.asInstanceOf[AnyRef]) {
         res
@@ -222,6 +229,14 @@ private[dottyreflection] trait ReflectionUtil { this: InspectorBase =>
     def paramVariance(ctx: InternalContext): Flags
   }
 
+  type InternalSymbol = {
+    def denot(ctx: InternalContext): InternalDenot
+  }
+
+  type InternalDenot = {
+    def info(ctx: InternalContext): TypeRepr
+  }
+
   object InternalContext {
     opaque type InternalContext = Any
   }

izumi-reflect/izumi-reflect/src/test/scala/izumi/reflect/test/SharedLightTypeTagTest.scala

@@ -1,6 +1,6 @@
 package izumi.reflect.test
 
-import izumi.reflect.macrortti.LightTypeTagRef.{AbstractReference, AppliedNamedReference, Boundaries, FullReference, NameReference, TypeParam}
+import izumi.reflect.macrortti.LightTypeTagRef.{AbstractReference, AppliedNamedReference, Boundaries, FullReference, NameReference, TypeParam, Variance}
 import izumi.reflect.macrortti._
 
 import scala.collection.immutable.ListSet
@@ -488,7 +488,7 @@ abstract class SharedLightTypeTagTest extends TagAssertions {
       object A extends Base
       object B extends Base
 
-      assertDifferent(LTT[A.Nested.Member],  LTT[B.Nested.Member])
+      assertDifferent(LTT[A.Nested.Member], LTT[B.Nested.Member])
     }
 
     "properly dealias and assign prefixes to existential types and wildcards" in {
@@ -784,6 +784,38 @@ abstract class SharedLightTypeTagTest extends TagAssertions {
       assertRepr(`LTT[_]`[S[Unit, *]], "λ %0 → Either[+0,+Unit]")
     }
 
+    "regression test for https://github.com/zio/izumi-reflect/issues/511" in {
+      class Foo5[-A, B, -C, +DXX, +E]
+      class Foo10[F[_], +G[_], -H[-_, +_], I, +J[+_, +_], B, -A, -C, +E, +DXX] extends Foo5[A, B, C, DXX, E]
+
+      val tag1 = LTT[Foo5[Int, String, Double, Float, Long]]
+
+      assert(tag1.ref.isInstanceOf[FullReference])
+      assert(
+        tag1.ref.asInstanceOf[FullReference].parameters.map(_.variance)
+        == List(Variance.Contravariant, Variance.Invariant, Variance.Contravariant, Variance.Covariant, Variance.Covariant)
+      )
+
+      val tag2 = LTT[Foo10[Option, List, Function1, Boolean, Either, Int, String, Double, Float, Long]]
+
+      assert(tag2.ref.isInstanceOf[FullReference])
+      assert(
+        tag2.ref.asInstanceOf[FullReference].parameters.map(_.variance)
+        == List(
+          Variance.Invariant,
+          Variance.Covariant,
+          Variance.Contravariant,
+          Variance.Invariant,
+          Variance.Covariant,
+          Variance.Invariant,
+          Variance.Contravariant,
+          Variance.Contravariant,
+          Variance.Covariant,
+          Variance.Covariant
+        )
+      )
+    }
+
   }
 
 }