Avoid spurious "illegal await" error in IDE with nesting

The presentation compiler runs with `-Ymacro-expand:discard`, which
retains the macro expandee in the typechecked trees, rather than
substituting in the expansion. This mode was motivated as a means
to keep IDE functionality working (e.g. completion, navigation,
refactoring) inside macro applications.

However, if one has nested async macro applications, as reported in
the IDE ticket:

  https://www.assembla.com/spaces/scala-ide/tickets/1002561

... the expansion of the outer async application was reporting
await calls enclosed by the inner async application.

This change tweaks the traversers used for this analysis to
stop whenever it sees an async.

1 files changed, 20 insertions, 0 deletions

diff --git a/src/test/scala/scala/async/run/WarningsSpec.scala b/src/test/scala/scala/async/run/WarningsSpec.scala
index 00c6466..c80bf9e 100644
--- a/src/test/scala/scala/async/run/WarningsSpec.scala
+++ b/src/test/scala/scala/async/run/WarningsSpec.scala
@@ -74,4 +74,24 @@ class WarningsSpec {
     run.compileSources(sourceFile :: Nil)
     assert(!global.reporter.hasErrors, global.reporter.asInstanceOf[StoreReporter].infos)
   }
+
+  @Test
+  def ignoreNestedAwaitsInIDE_t1002561() {
+    // https://www.assembla.com/spaces/scala-ide/tickets/1002561
+    val global = mkGlobal("-cp ${toolboxClasspath} -Yrangepos -Ystop-after:typer ")
+    val source = """
+        | class Test {
+        |  def test = {
+        |    import scala.async.Async._, scala.concurrent._, ExecutionContext.Implicits.global
+        |    async {
+        |      1 + await({def foo = (async(await(async(2)))); foo})
+        |    }
+        |  }
+        |}
+      """.stripMargin
+    val run = new global.Run
+    val sourceFile = global.newSourceFile(source)
+    run.compileSources(sourceFile :: Nil)
+    assert(!global.reporter.hasErrors, global.reporter.asInstanceOf[StoreReporter].infos)
+  }
 }