Add tests that show #409

core/src/test/scala/scala/pickling/pickler/DoublePicklerUnpicklerGeneration.scala

@@ -0,0 +1,34 @@
+package scala.pickling.pickler
+
+import org.scalatest.FunSuite
+import scala.pickling._, Defaults._, static._, json._
+
+class DoublePicklerUnpicklerGeneration extends FunSuite {
+
+  case class Foo[T](value: T)
+
+  import scala.pickling.internal.currentRuntime
+
+  test("generation of pickler should return an already generated pickler") {
+
+    // This should get the already generated pickler
+    // which is already stored in the mapPickler
+    val pickler = implicitly[Pickler[Foo[List[String]]]]
+    val key = pickler.tag.key
+    val alreadyGenPickler = currentRuntime.picklers.lookupPickler(key)
+
+    assert(alreadyGenPickler.get === pickler)
+
+  }
+
+  test("generation of unpickler should return an already generated unpickler") {
+
+    val unpickler = implicitly[Unpickler[Foo[List[String]]]]
+    val key = unpickler.tag.key
+    val alreadyGenUnpickler = currentRuntime.picklers.lookupUnpickler(key)
+
+    assert(alreadyGenUnpickler.get === unpickler)
+
+  }
+
+}