Add a test to interrogate the expanded tree.

 - checks that only one function is synthesized
 - checks the set of vars created (TODO minimize these)
 - use x$1 rather than x1 for the freshened names for lifted vars.
 - make execContext a val, not a var.

1 files changed, 38 insertions, 0 deletions

diff --git a/src/test/scala/scala/async/TreeInterrogation.scala b/src/test/scala/scala/async/TreeInterrogation.scala
new file mode 100644
index 0000000..7c277b1
--- /dev/null
+++ b/src/test/scala/scala/async/TreeInterrogation.scala
@@ -0,0 +1,38 @@
+package scala.async
+
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+import org.junit.Test
+import AsyncId._
+
+@RunWith(classOf[JUnit4])
+class TreeInterrogation {
+  @Test
+  def `a minimal set of vals are lifted to vars`() {
+    val cm = reflect.runtime.currentMirror
+    val tb = mkToolbox()
+    val tree = mkToolbox().parse(
+      """| import _root_.scala.async.AsyncId._
+        | async {
+        |   val x = await(1)
+        |   val y = x * 2
+        |   val z = await(x * 3)
+        |   z
+        | }""".stripMargin)
+    val tree1 = tb.typeCheck(tree)
+
+    // println(cm.universe.showRaw(tree1))
+
+    import tb.mirror.universe._
+    val functions = tree1.collect {
+      case f: Function => f
+    }
+    functions.size mustBe 1
+
+    val varDefs = tree1.collect {
+      case ValDef(mods, name, _, _) if mods.hasFlag(Flag.MUTABLE) => name
+    }
+    // TODO no need to lift `y` as it is only accessed from a single state.
+    varDefs.map(_.decoded).toSet mustBe(Set("state$async", "onCompleteHandler$async", "x$1", "z$1", "y$1"))
+  }
+}