From 6c243fba5c8982f3cf355f5c53226ab69e9f50be Mon Sep 17 00:00:00 2001
From: Kai <450507+neko-kai@users.noreply.github.com>
Date: Tue, 30 May 2023 01:11:01 +0100
Subject: [PATCH] Fix #391, fix regression with variance on Scala 3.3.0. Use
 fixes from https://github.com/lampepfl/dotty/pull/17568

---
 .../reflect/dottyreflection/Inspector.scala   |  7 +++++--
 .../dottyreflection/ReflectionUtil.scala      | 21 +++++++++++++------
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/izumi-reflect/izumi-reflect/src/main/scala-3/izumi/reflect/dottyreflection/Inspector.scala b/izumi-reflect/izumi-reflect/src/main/scala-3/izumi/reflect/dottyreflection/Inspector.scala
index 37b86d53..d100adac 100644
--- a/izumi-reflect/izumi-reflect/src/main/scala-3/izumi/reflect/dottyreflection/Inspector.scala
+++ b/izumi-reflect/izumi-reflect/src/main/scala-3/izumi/reflect/dottyreflection/Inspector.scala
@@ -74,13 +74,16 @@ abstract class Inspector(protected val shift: Int, val context: Queue[Inspector.
           case Nil =>
             makeNameReferenceFromType(appliedType.tycon)
           case _ =>
-            val symbolVariances = appliedType.tycon.typeSymbol.typeMembers.map(extractVariance)
+            val symbolVariances = appliedType.tycon.typeSymbol.typeMembers.collect {
+              case s if s.isTypeParam =>
+                extractVariance(s)
+            }
             val variances = if (symbolVariances.sizeCompare(appliedType.args) < 0) {
               appliedType.tycon match {
                 case typeParamRef: ParamRef =>
                   typeParamRef._underlying match {
                     case TypeBounds(_, hi) =>
-                      hi._declaredVariancesIfHKTypeLambda.fold(Nil)(_.map(extractVariance))
+                      hi._paramVariancesIfHKTypeLambda.fold(Nil)(_.map(extractVariance))
                     case _ =>
                       Nil
                   }
diff --git a/izumi-reflect/izumi-reflect/src/main/scala-3/izumi/reflect/dottyreflection/ReflectionUtil.scala b/izumi-reflect/izumi-reflect/src/main/scala-3/izumi/reflect/dottyreflection/ReflectionUtil.scala
index 1ab34d77..c8ff6671 100644
--- a/izumi-reflect/izumi-reflect/src/main/scala-3/izumi/reflect/dottyreflection/ReflectionUtil.scala
+++ b/izumi-reflect/izumi-reflect/src/main/scala-3/izumi/reflect/dottyreflection/ReflectionUtil.scala
@@ -84,6 +84,7 @@ private[dottyreflection] trait ReflectionUtil { this: InspectorBase =>
   }
 
   import ReflectionUtil.reflectiveUncheckedNonOverloadedSelectable
+  import InternalContext.InternalContext
 
   extension (typeRef: TypeRef | ParamRef) {
     protected final def _underlying: TypeRepr = {
@@ -102,14 +103,16 @@ private[dottyreflection] trait ReflectionUtil { this: InspectorBase =>
 //        )
 //      underlying.asInstanceOf[TypeRepr]
 
-      typeRef.asInstanceOf[InternalTypeRefOrParamRef].underlying(using qctx._ctx)
+      typeRef.asInstanceOf[InternalTypeRefOrParamRef].underlying(qctx._ctx)
     }
   }
 
   extension (typeRepr: TypeRepr) {
-    protected final def _declaredVariancesIfHKTypeLambda: Option[List[Flags]] = {
+    protected final def _paramVariancesIfHKTypeLambda: Option[List[Flags]] = {
       try {
-        Some(typeRepr.asInstanceOf[InternalHKTypeLambda].declaredVariances)
+        val params = typeRepr.asInstanceOf[InternalHKTypeLambda].typeParams
+        val flags = params.map(_.paramVariance(qctx._ctx))
+        Some(flags)
       } catch {
         case _: NoSuchMethodException => None
       }
@@ -208,14 +211,20 @@ private[dottyreflection] trait ReflectionUtil { this: InspectorBase =>
   }
 
   type InternalTypeRefOrParamRef = {
-    def underlying(using InternalContext): TypeRepr
+    def underlying(ctx: InternalContext): TypeRepr
   }
 
   type InternalHKTypeLambda = {
-    def declaredVariances: List[Flags]
+    val typeParams: List[InternalLambdaParam]
   }
 
-  opaque type InternalContext = Any
+  type InternalLambdaParam = {
+    def paramVariance(ctx: InternalContext): Flags
+  }
+
+  object InternalContext {
+    opaque type InternalContext = Any
+  }
 
 }