Silently handle handle eval exceptions in PolymerExpressions

pkg/polymer_expressions/test/syntax_test.dart

Index: pkg/polymer_expressions/test/syntax_test.dart
diff --git a/pkg/polymer_expressions/test/syntax_test.dart b/pkg/polymer_expressions/test/syntax_test.dart
index 8e5b322326487c0bd2b4d1d37b27198b429e0bf6..6415740b010950dcc9f0a51ced35dccf1cd4b7ff 100644
--- a/pkg/polymer_expressions/test/syntax_test.dart
+++ b/pkg/polymer_expressions/test/syntax_test.dart
@@ -5,11 +5,12 @@
 import 'dart:async';
 import 'dart:html';
 
+import 'package:mdv/mdv.dart' as mdv;
+import 'package:logging/logging.dart';
+import 'package:observe/observe.dart';
 import 'package:polymer_expressions/polymer_expressions.dart';
-import 'package:unittest/unittest.dart';
 import 'package:unittest/html_enhanced_config.dart';
-import 'package:observe/observe.dart';
-import 'package:mdv/mdv.dart' as mdv;
+import 'package:unittest/unittest.dart';
 
 main() {
   mdv.initialize();
@@ -62,6 +63,23 @@ main() {
       expect(testDiv.nodes.length, 1);
       expect(testDiv.nodes[0].id, 'test');
     });
+
+    test('should silently handle bad variable names', () {
+      var logFuture = Logger.root.onRecord.toList();

[Jennifer Messerly, 2013/09/18 18:52:27]

hmmm, I think this should be scoped to polymer_expressions logger. Otherwise if
someone else (probably me :) ) adds logging to another level of the system, it
can break this test.

+      testDiv.nodes.add(new Element.html('''
+          <template id="test" bind>{{ foo }}</template>'''));
+      query('#test')
+        ..bindingDelegate = new PolymerExpressions()
+        ..model = null;

[Jennifer Messerly, 2013/09/18 18:52:27]

fyi -- I don't think setting model to null is required. setting the binding
delegate should be enough. See:

https://github.com/dart-lang/bleeding_edge/blob/bed46364329287aa4fc5da95f8593...

maybe fix the other tests too?

[justinfagnani, 2013/09/18 21:56:29]

Done.

+      return new Future(() => null).then((_) {

[Jennifer Messerly, 2013/09/18 18:52:27]

confused by `new Future(() => null).then((_) {` ... did you mean `new Future(()
{`

[justinfagnani, 2013/09/18 21:56:29]

Done.

+        Logger.root.clearListeners();
+        return logFuture.then((records) {
+          expect(records.length, 1);
+          expect(records.first.message, contains('Error evaluating expression'));

[Jennifer Messerly, 2013/09/18 18:52:27]

long line. records[0].message? :)

[justinfagnani, 2013/09/18 21:56:29]

Done.

+          expect(records.first.message, contains('foo'));
+        });
+      });
+    });
   });
 }