Add test for complex in expressions in polymer_expressions

pkg/polymer_expressions/test/eval_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library eval_test;
 
 import 'dart:async';
 
 // Import mirrors to cause all mirrors to be retained by dart2js.
 // The tests reflect on LinkedHashMap.length and String.length.
@@ skipping 198 matching lines @@
       expectEval('a || b', false, null, {'a': false, 'b': null});
       expectEval('a || b', false, null, {'a': null, 'b': null});
     });
 
     test('should evaluate an "in" expression', () {
       var scope = new Scope(variables: {'items': [1, 2, 3]});
       var comprehension = eval(parse('item in items'), scope);
       expect(comprehension.iterable, orderedEquals([1, 2, 3]));
     });
 
+    test('should evaluate complex "in" expressions', () {
+      var holder = new ListHolder([1, 2, 3]);
+      var scope = new Scope(variables: {'holder': holder});
+      var comprehension = eval(parse('item in holder.items'), scope);
+      expect(comprehension.iterable, orderedEquals([1, 2, 3]));
+    });
+
     test('should handle null iterators in "in" expressions', () {
       var scope = new Scope(variables: {'items': null});
       var comprehension = eval(parse('item in items'), scope);
       expect(comprehension, isNotNull);
       expect(comprehension.iterable, []);
     });
 
   });
 
   group('assign', () {
@@ skipping 125 matching lines @@
 
   int age;
   Foo child;
   List<int> items;
 
   Foo({name, this.age, this.child, this.items}) : _name = name;
 
   int x() => age * age;
 }
 
+@reflectable
+class ListHolder {
+  List items;
+  ListHolder(this.items);
+}
+
 parseInt([int radix = 10]) => new IntToString(radix: radix);
 
 class IntToString extends Transformer<int, String> {
   final int radix;
   IntToString({this.radix: 10});
   int forward(String s) => int.parse(s, radix: radix);
   String reverse(int i) => '$i';
 }
 
 add(int i) => new Add(i);
@@ skipping 36 matching lines @@
   return Future.wait([future, new Future(() {
     expect(passed, true, reason: "Didn't receive a change notification on $s");
   })]);
 }
 
 // Regression test from https://code.google.com/p/dart/issues/detail?id=13459
 class WordElement extends Observable {
   @observable List chars1 = 'abcdefg'.split('');
   @reflectable List filteredList(List original) => [original[0], original[1]];
 }