Fix #8460: expose children of sealed trait in Reflection

compiler/src/dotty/tools/dotc/tastyreflect/ReflectionCompilerInterface.scala

@@ -1753,6 +1753,9 @@ class ReflectionCompilerInterface(val rootContext: core.Contexts.Context) extend
       case sym if sym.is(Flags.CaseAccessor) => sym.asTerm
     }
 
+  def Symbol_children(self: Symbol)(using ctx: Context): List[Symbol] =
+    dotty.tools.dotc.transform.SymUtils(self).children
+
   private def isField(sym: Symbol)(using ctx: Context): Boolean = sym.isTerm && !sym.is(Flags.Method)
 
   def Symbol_of(fullName: String)(using ctx: Context): Symbol =

library/src/scala/tasty/Reflection.scala

@@ -2254,6 +2254,10 @@ class Reflection(private[scala] val internal: CompilerInterface) { self =>
     /** Shows the tree as fully typed source code */
     def showWith(syntaxHighlight: SyntaxHighlight)(using ctx: Context): String =
       new SourceCodePrinter[self.type](self)(syntaxHighlight).showSymbol(sym)
+
+    /** Case class or case object children of a sealed trait */
+    def children(using ctx: Context): List[Symbol] =
+      internal.Symbol_children(sym)
   }
 
 

library/src/scala/tasty/reflect/CompilerInterface.scala

@@ -1350,6 +1350,9 @@ trait CompilerInterface {
 
   def Symbol_noSymbol(using ctx: Context): Symbol
 
+  /** Case class or case object children of a sealed trait */
+  def Symbol_children(self: Symbol)(using ctx: Context): List[Symbol]
+
 
   ///////////
   // FLAGS //

tests/run-custom-args/tasty-inspector/i8460.scala

@@ -0,0 +1,48 @@
+import scala.tasty.Reflection
+import scala.tasty.inspector._
+
+// Ambiguous member names
+sealed trait Vehicle
+case class Truck(numberOfWheels: Int) extends Vehicle
+case class Car(numberOfWheels: Int, color: String) extends Vehicle
+case class Plane(numberOfEngines: Int) extends Vehicle
+
+// Case object implementation
+sealed trait Flavor
+case object Vanilla extends Flavor
+case object Chocolate extends Flavor
+case object Bourbon extends Flavor
+
+object Test {
+  def main(args: Array[String]): Unit = {
+
+    // Tasty Scala Class
+    val inspect1 = new TestInspector_Children()
+    inspect1.inspect("", List("Vehicle"))
+    assert(inspect1.kids == List("Truck","Car","Plane"))
+
+    // Java Class
+    val inspect2 = new TestInspector_Children()
+    inspect2.inspect("", List("Flavor"))
+    assert(inspect2.kids == List("Vanilla","Chocolate","Bourbon"))
+  }
+}
+
+class TestInspector_Children() extends TastyInspector:
+
+  var kids: List[String] = Nil
+
+  protected def processCompilationUnit(reflect: Reflection)(root: reflect.Tree): Unit =
+    import reflect._
+    inspectClass(reflect)(root)
+
+  private def inspectClass(reflect: Reflection)(tree: reflect.Tree): Unit =
+    import reflect.{given _, _}
+    tree match {
+      case t: reflect.PackageClause =>
+        t.stats.map( m => inspectClass(reflect)(m) )
+      case t: reflect.ClassDef =>
+        kids = t.symbol.children.map(_.fullName)
+
+      case x =>
+    }