Make Dartium JS interop implementation more robust in the presence of JS paths that touch dart:html…

tests/html/js_typed_interop_test.dart

Index: tests/html/js_typed_interop_test.dart
diff --git a/tests/html/js_typed_interop_test.dart b/tests/html/js_typed_interop_test.dart
index 0e7cd0c301e0095936adeb5787c03fb7657478f9..14d931f0d69ec46d16ee00151d29406804ad76fe 100644
--- a/tests/html/js_typed_interop_test.dart
+++ b/tests/html/js_typed_interop_test.dart
@@ -86,6 +86,11 @@ _injectJs() {
       return this.str.charCodeAt(index);
     }
   };
+  function getCanvasContext() {
+    return document.createElement('canvas').getContext('2d');
+  }
+  window.windowProperty = 42;
+  document.documentProperty = 45;
 """);
 }
 
@@ -176,6 +181,15 @@ class StringWrapper {
 @JS()
 external confuse(obj);
 
+@JS()
+external CanvasRenderingContext2D getCanvasContext();
+
+@JS('window.window.document.documentProperty')
+external num get propertyOnDocument;
+
+@JS('window.self.window.window.windowProperty')
+external num get propertyOnWindow;
+
 main() {
   _injectJs();
 
@@ -374,4 +388,13 @@ main() {
       expect(selection is List, isTrue);
     });
   });
+  group('html', () {
+    test('return html type', () {
+      expect(getCanvasContext() is CanvasRenderingContext2D, isTrue);
+    });
+    test('js path contains html types', () {

[Alan Knight, 2015/11/04 18:44:14]

nit: Not clear to me what this testing.

[Jacob, 2015/11/04 19:01:30]

This case would fail previously 
note the path to propertyOnWindow intentionally bounces back between types that
were auto-proxied with the old dart:js JsObject class.

+      expect(propertyOnWindow, equals(42));
+      expect(propertyOnDocument, equals(45));
+    });
+  });
 }