Add test cases for macro wunused

Author: szymon-rd

tests/neg-custom-args/fatal-warnings/i16876/Macro.scala

@@ -0,0 +1,23 @@
+import scala.quoted.*
+
+def findMethodSymbol(using q: Quotes)(s: quotes.reflect.Symbol): quotes.reflect.Symbol =
+  if s.isDefDef then
+    s
+  else
+    findMethodSymbol(using q)(s.owner)
+end findMethodSymbol
+
+
+inline def adder: Int = ${
+  adderImpl
+}
+
+def adderImpl(using q: Quotes): Expr[Int] =
+  import quotes.reflect.*
+
+  val inputs = findMethodSymbol(using q)(q.reflect.Symbol.spliceOwner).tree match
+    case DefDef(_, params, _, _) =>
+      params.last match
+        case TermParamClause(valDefs) =>
+          valDefs.map(vd => Ref(vd.symbol).asExprOf[Int])
+  inputs.reduce((exp1, exp2) => '{ $exp1 + $exp2 })

tests/neg-custom-args/fatal-warnings/i16876/Test.scala

@@ -0,0 +1,11 @@
+// scalac: -Wunused:all
+
+object Foo {
+  private def myMethod(a: Int, b: Int, c: Int) = adder // ok
+  myMethod(1, 2, 3)
+
+  private def myMethodFailing(a: Int, b: Int, c: Int) = a + 0 // error // error
+  myMethodFailing(1, 2, 3)
+}
+
+