Upgrade to Scala 3.4.2.

And apply changes due to
scala/scala3#19761

Author: sjrd

build.sbt

@@ -3,7 +3,7 @@ import sbt.internal.util.ManagedLogger
 
 import org.scalajs.jsenv.nodejs.NodeJSEnv
 
-val usedScalaCompiler = "3.4.0"
+val usedScalaCompiler = "3.4.2"
 val usedTastyRelease = usedScalaCompiler
 val scala2Version = "2.13.14"
 

tasty-query/shared/src/test/scala/tastyquery/PrintersTest.scala

@@ -211,7 +211,11 @@ class PrintersTest extends UnrestrictedUnpicklingSuite:
     )
 
     val MatchTypeClass = ctx.findTopLevelClass("simple_trees.MatchType")
-    testShowBasicMember(MatchTypeClass, typeName("MT"), "type MT[X] = X match { case Int => String }")
+    testShowBasicMember(
+      MatchTypeClass,
+      typeName("MT"),
+      "type MT[X] <: scala.Predef.String = X match { case Int => String }"
+    )
     testShowBasicMember(
       MatchTypeClass,
       typeName("MTWithBound"),
@@ -220,9 +224,14 @@ class PrintersTest extends UnrestrictedUnpicklingSuite:
     testShowBasicMember(
       MatchTypeClass,
       typeName("MTWithWildcard"),
-      "type MTWithWildcard[X] = X match { case _ => Int }"
+      "type MTWithWildcard[X] <: scala.Int = X match { case _ => Int }"
+    )
+    // The `<: t` is completely wrong. See https://github.com/scala/scala3/issues/21256
+    testShowBasicMember(
+      MatchTypeClass,
+      typeName("MTWithBind"),
+      "type MTWithBind[X] <: t = X match { case List[t] => t }"
     )
-    testShowBasicMember(MatchTypeClass, typeName("MTWithBind"), "type MTWithBind[X] = X match { case List[t] => t }")
   }
 
   testWithContext("multiline tree printers") {
@@ -286,7 +295,7 @@ class PrintersTest extends UnrestrictedUnpicklingSuite:
     testShowMultilineMember(
       MatchTypeClass,
       typeName("MT"),
-      """type MT[X] = X match {
+      """type MT[X] <: scala.Predef.String = X match {
         |  case Int => String
         |}""".stripMargin
     )
@@ -300,14 +309,15 @@ class PrintersTest extends UnrestrictedUnpicklingSuite:
     testShowMultilineMember(
       MatchTypeClass,
       typeName("MTWithWildcard"),
-      """type MTWithWildcard[X] = X match {
+      """type MTWithWildcard[X] <: scala.Int = X match {
         |  case _ => Int
         |}""".stripMargin
     )
+    // The `<: t` is completely wrong. See https://github.com/scala/scala3/issues/21256
     testShowMultilineMember(
       MatchTypeClass,
       typeName("MTWithBind"),
-      """type MTWithBind[X] = X match {
+      """type MTWithBind[X] <: t = X match {
         |  case List[t] => t
         |}""".stripMargin
     )

tasty-query/shared/src/test/scala/tastyquery/ReadTreeSuite.scala

@@ -1904,8 +1904,8 @@ class ReadTreeSuite extends RestrictedUnpicklingSuite {
               List(TypeParam(SimpleTypeName("X"), NothingAnyTypeBoundsTree(), _)),
               TypeAliasDefinitionTree(
                 MatchTypeTree(
-                  // No bound on the match result
-                  TypeWrapper(TypeRefInternal(ScalaPackageRef(), tpnme.Any)),
+                  // No bound on the match result -- inferred to be String since 3.4.2
+                  TypeWrapper(TypeRefInternal(_, tpnme.String)),
                   TypeIdent(SimpleTypeName("X")),
                   List(TypeCaseDef(TypeIdent(SimpleTypeName("Int")), TypeIdent(SimpleTypeName("String"))))
                 )
@@ -1946,8 +1946,8 @@ class ReadTreeSuite extends RestrictedUnpicklingSuite {
               List(TypeParam(SimpleTypeName("X"), NothingAnyTypeBoundsTree(), _)),
               TypeAliasDefinitionTree(
                 MatchTypeTree(
-                  // No bound on the match result
-                  TypeWrapper(TypeRefInternal(ScalaPackageRef(), tpnme.Any)),
+                  // No bound on the match result -- inferred since 3.4.2
+                  TypeWrapper(_),
                   TypeIdent(SimpleTypeName("X")),
                   List(TypeCaseDef(TypeIdent(tpnme.Wildcard), TypeIdent(SimpleTypeName("Int"))))
                 )
@@ -1965,8 +1965,8 @@ class ReadTreeSuite extends RestrictedUnpicklingSuite {
               List(TypeParam(SimpleTypeName("X"), NothingAnyTypeBoundsTree(), _)),
               TypeAliasDefinitionTree(
                 MatchTypeTree(
-                  // No bound on the match result
-                  TypeWrapper(TypeRefInternal(ScalaPackageRef(), tpnme.Any)),
+                  // No bound on the match result -- inferred since 3.4.2
+                  TypeWrapper(_),
                   TypeIdent(SimpleTypeName("X")),
                   List(
                     TypeCaseDef(
@@ -1995,7 +1995,8 @@ class ReadTreeSuite extends RestrictedUnpicklingSuite {
                 Select(rhs, SignedName(SimpleName("$asInstanceOf$"), _, _)),
                 TypeWrapper(
                   ty.MatchType(
-                    TypeRefInternal(ScalaPackageRef(), SimpleTypeName("Any")),
+                    // No bound on the match result -- inferred since 3.4.2
+                    _,
                     TypeRefInternal(_, xRef),
                     List(
                       ty.MatchTypeCase(
@@ -2026,7 +2027,8 @@ class ReadTreeSuite extends RestrictedUnpicklingSuite {
                 Select(rhs, SignedName(SimpleName("$asInstanceOf$"), _, _)),
                 TypeWrapper(
                   ty.MatchType(
-                    TypeRefInternal(ScalaPackageRef(), SimpleTypeName("Any")),
+                    // No bound on the match result -- inferred since 3.4.2
+                    _,
                     TypeRefInternal(_, xRef),
                     List(
                       ty.MatchTypeCase(

tasty-query/shared/src/test/scala/tastyquery/SignatureSuite.scala

@@ -408,7 +408,8 @@ class SignatureSuite extends UnrestrictedUnpicklingSuite:
     val MatchType = ctx.findTopLevelClass("simple_trees.MatchType")
 
     val unboundUnreducibleSig = MatchType.findNonOverloadedDecl(termName("unboundUnreducibleSig"))
-    assertSigned(unboundUnreducibleSig, "(1,java.lang.Object):java.lang.Object")
+    // Was "(1,java.lang.Object):java.lang.Object" < 3.4.2
+    assertSigned(unboundUnreducibleSig, "(1,java.lang.Object):java.lang.String")
 
     val unboundReducibleSig = MatchType.findNonOverloadedDecl(termName("unboundReducibleSig"))
     assertSigned(unboundReducibleSig, "(1,scala.Int):java.lang.String")
@@ -421,7 +422,8 @@ class SignatureSuite extends UnrestrictedUnpicklingSuite:
 
     // this one is suspicious, but it is what dotc does (I expected `Object` instead of `Object[]`)
     val arrayOfUnboundUnreducibleSig = MatchType.findNonOverloadedDecl(termName("arrayOfUnboundUnreducibleSig"))
-    assertSigned(arrayOfUnboundUnreducibleSig, "(1,java.lang.Object):java.lang.Object[]")
+    // Was "(1,java.lang.Object):java.lang.Object[]" < 3.4.2
+    assertSigned(arrayOfUnboundUnreducibleSig, "(1,java.lang.Object):java.lang.String[]")
 
     val arrayOfUnboundReducibleSig = MatchType.findNonOverloadedDecl(termName("arrayOfUnboundReducibleSig"))
     assertSigned(arrayOfUnboundReducibleSig, "(1,scala.Int):java.lang.String[]")

test-sources/src/main/scala/simple_trees/AccessModifiers.scala

@@ -2,7 +2,7 @@ package simple_trees
 
 import scala.annotation.nowarn
 
-@nowarn("msg=The \\[this\\] qualifier will be deprecated")
+@nowarn("msg=Ignoring \\[this\\] qualifier")
 class AccessModifiers(
   localParam: Int,
   private[this] val privateThisParam: Int,