Fix precedence of ternary operators in polymer expressions

pkg/polymer_expressions/test/parser_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 parser_test;
 
 import 'package:polymer_expressions/parser.dart';
 import 'package:polymer_expressions/expression.dart';
 import 'package:unittest/unittest.dart';
 
@@ skipping 141 matching lines @@
           index(ident('c'), ident('d'))));
     });
 
     test('should parse ternary operators', () {
       expectParse('a ? b : c', ternary(ident('a'), ident('b'), ident('c')));
       expectParse('a.a ? b.a : c.a', ternary(getter(ident('a'), 'a'),
           getter(ident('b'), 'a'), getter(ident('c'), 'a')));
       expect(() => parse('a + 1 ? b + 1 :: c.d + 3'), throws);
     });
 
+    test('ternary operators have lowest associativity', () {
+      expectParse('a == b ? c + d : e - f', ternary(
+            binary(ident('a'), '==', ident('b')),
+            binary(ident('c'), '+', ident('d')),
+            binary(ident('e'), '-', ident('f'))));
+
+      expectParse('a.x == b.y ? c + d : e - f', ternary(
+            binary(getter(ident('a'), 'x'), '==', getter(ident('b'), 'y')),
+            binary(ident('c'), '+', ident('d')),
+            binary(ident('e'), '-', ident('f'))));
+
+      expectParse('a.x == b.y ? c + d : e - f', ternary(
+            binary(getter(ident('a'), 'x'), '==', getter(ident('b'), 'y')),
+            binary(ident('c'), '+', ident('d')),
+            binary(ident('e'), '-', ident('f'))));
+    });
+
     test('should parse a filter chain', () {
       expectParse('a | b | c', binary(binary(ident('a'), '|', ident('b')),
           '|', ident('c')));
     });
 
     test('should parse comprehension', () {
       expectParse('a in b', inExpr(ident('a'), ident('b')));
       expectParse('a in b.c',
           inExpr(ident('a'), getter(ident('b'), 'c')));
       expectParse('a in b + c',
@@ skipping 32 matching lines @@
 
     test('should parse list literals', () {
       expectParse('[1, "a", b]',
           listLiteral([literal(1), literal('a'), ident('b')]));
       expectParse('[[1, 2], [3, 4]]',
           listLiteral([listLiteral([literal(1), literal(2)]),
                        listLiteral([literal(3), literal(4)])]));
     });
   });
 }