Fix #6988: add test

library/src/scala/tasty/reflect/TreeOps.scala

@@ -241,12 +241,22 @@ trait TreeOps extends Core {
 
   object Ref {
 
-    /** Create a reference tree */
+    /** Create a reference tree from a symbol
+      *
+      *  If `sym` refers to a class member `foo` in class `C`,
+      *  returns a tree representing `C.this.foo`.
+      *
+      *  If `sym` refers to a local definition `foo`, returns
+      *  a tree representing `foo`.
+      *
+      *  @note In both cases, the constructed tree should only
+      *  be spliced into the places where such accesses make sense.
+      *  For example, it is incorrect to have `C.this.foo` outside
+      *  the class body of `C`, or have `foo` outside the lexical
+      *  scope for the definition of `foo`.
+      */
     def apply(sym: Symbol)(given ctx: Context): Ref =
       internal.Ref_apply(sym)
-
-    // TODO def copy(original: Tree)(name: String)(given ctx: Context): Ref
-
   }
 
   given (given Context): IsInstanceOf[Ident] = internal.isInstanceOfIdent

tests/run-macros/i6988/FirstArg_1.scala

@@ -0,0 +1,32 @@
+package foo
+
+case class FirstArg(value: Any, source: String)
+object FirstArg {
+  inline given create: FirstArg = ${Macros.argsImpl}
+}
+
+object Macros {
+  import scala.quoted._
+
+  def argsImpl(given qctx: QuoteContext): Expr[FirstArg] = {
+    import qctx.tasty.{_, given}
+
+    def enclosingClass(cur: Symbol = rootContext.owner): Symbol =
+      if (cur.isClassDef) cur
+      else enclosingClass(cur.owner)
+
+    def enclosingParamList(owner: Symbol): Seq[Seq[Symbol]] =
+      if owner.isClassDef then
+        owner.tree match
+          case tdef: ClassDef =>
+            tdef.constructor.paramss map { _ map {_.symbol }}
+      else enclosingParamList(owner.owner)
+
+    def literal(value: String): Expr[String] =
+      Literal(Constant(value)).seal.asInstanceOf[Expr[String]]
+    val paramss = enclosingParamList(rootContext.owner)
+    val firstArg = paramss.flatten.head
+    val ref = Select.unique(This(enclosingClass()), firstArg.name)
+    '{ FirstArg(${ref.seal}, ${Expr(firstArg.name)}) }
+  }
+}

tests/run-macros/i6988/Test_2.scala

@@ -0,0 +1,16 @@
+object Test {
+  var firstArgName = ""
+  var firstArgValue: Any = ""
+  def main(args: Array[String]): Unit = {
+    val x = new Foo("something", 2L, false)
+    assert("p1" == firstArgName)
+    assert("something" == firstArgValue)
+  }
+  def debug(given foo.FirstArg): Unit = {
+    firstArgName = summon[foo.FirstArg].source
+    firstArgValue = summon[foo.FirstArg].value
+  }
+  class Foo(p1: String, p2: Long, p3: Boolean) {
+    debug
+  }
+}