Handle for-in loops

test/checker/inferred_type_test.dart

Index: test/checker/inferred_type_test.dart
diff --git a/test/checker/inferred_type_test.dart b/test/checker/inferred_type_test.dart
index 12bcec6028d79c5ff19198a95a279fee9020fee4..757204e8a28a4862c93b922247622945e93713ef 100644
--- a/test/checker/inferred_type_test.dart
+++ b/test/checker/inferred_type_test.dart
@@ -587,9 +587,37 @@ void main() {
       }
 
       test() {
-        var l = List<Foo>();
+        var list = <Foo>[];
         for (var x in list) {
-          String y = /*info:DynamicCast should be severe:StaticTypeError*/x;
+          String y = /*severe:StaticTypeError*/x;
+        }
+
+        for (dynamic x in list) {
+          String y = /*info:DynamicCast*/x;
+        }
+
+        for (String x in /*severe:StaticTypeError*/list) {
+          String y = x;
+        }
+
+        var z;
+        for(z in list) {
+          String y = /*info:DynamicCast*/z;
+        }
+
+        Iterable iter = list;
+        for (Foo x in /*warning:DownCastComposite*/iter) {
+          var y = x;
+        }
+
+        dynamic iter2 = list;
+        for (Foo x in /*warning:DownCastComposite*/iter2) {
+          var y = x;
+        }
+
+        var map = <String, Foo>{};
+        for (var x in /*severe:StaticTypeError*/map) {

[Siggi Cherem (dart-lang), 2015/03/30 23:42:12]

is this an error because the type is not iterable? could you add a little
comment to clarify?

[vsm, 2015/03/31 00:24:47]

Yes, a cast is needed and will fail here.  Note, I added another test case -
that one is unfortunately off.  Somehow, we're not computing that map.keys is an
Iterable<String> - at least not computing that soon enough.

+          String y = /*info:DynamicCast*/x;
         }
       }
       '''