Add StringLengthConstantExpression

tests/compiler/dart2js/constant_expression_test.dart

 // Copyright (c) 2015, 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 constant_expression_test;
 
 import 'dart:async';
 import 'package:async_helper/async_helper.dart';
 import 'package:expect/expect.dart';
 import 'package:compiler/src/constants/expressions.dart';
@@ skipping 34 matching lines @@
 const List<TestData> DATA = const [
   const TestData('', const [
     const ConstantData('null', ConstantExpressionKind.NULL),
     const ConstantData('false', ConstantExpressionKind.BOOL),
     const ConstantData('true', ConstantExpressionKind.BOOL),
     const ConstantData('0', ConstantExpressionKind.INT),
     const ConstantData('0.0', ConstantExpressionKind.DOUBLE),
     const ConstantData('"foo"', ConstantExpressionKind.STRING),
     const ConstantData('1 + 2', ConstantExpressionKind.BINARY),
     const ConstantData('-(1)', ConstantExpressionKind.UNARY, text: '-1'),
+    const ConstantData('"foo".length', ConstantExpressionKind.STRING_LENGTH),
     const ConstantData('identical(0, 1)', ConstantExpressionKind.IDENTICAL),
     const ConstantData('"a" "b"', ConstantExpressionKind.CONCATENATE,
                        text: '"ab"'),
     const ConstantData('identical', ConstantExpressionKind.FUNCTION),
     const ConstantData('true ? 0 : 1', ConstantExpressionKind.CONDITIONAL),
     const ConstantData('proxy', ConstantExpressionKind.VARIABLE),
     const ConstantData('Object', ConstantExpressionKind.TYPE),
     const ConstantData('#name', ConstantExpressionKind.SYMBOL),
     const ConstantData('const [0, 1]', ConstantExpressionKind.LIST),
     const ConstantData('const <int>[0, 1]', ConstantExpressionKind.LIST),
@@ skipping 76 matching lines @@
   ]),
   const TestData('''
 class A<T> implements B {
   final field1;
   const A({this.field1:42});
 }
 class B<S> implements C {
   const factory B({field1}) = A<B<S>>;
   // TODO(johnniwinther): Enable this when the constructor evaluator doesn't 
   // crash:
-  /*const factory B.named() = A<S>;*/
+  const factory B.named() = A<S>;
 }
 class C<U> {
   const factory C({field1}) = A<B<double>>;
 }
 ''', const [
     const ConstantData('const A()', ConstantExpressionKind.CONSTRUCTED,
         type: 'A<dynamic>',
         fields: const {'field(A#field1)': '42'}),
     const ConstantData('const A<int>(field1: 87)',
         ConstantExpressionKind.CONSTRUCTED,
@@ skipping 14 matching lines @@
         type: 'A<B<int>>',
         fields: const {
           'field(A#field1)': '87',
         }),
     const ConstantData('const C<int>(field1: 87)',
         ConstantExpressionKind.CONSTRUCTED,
         type: 'A<B<double>>',
         fields: const {
           'field(A#field1)': '87',
         }),
-    // TODO(johnniwinther): Enable this when the constructor evaluator doesn't
-    // crash:
-    /*const ConstantData('const B<int>.named()',
+    const ConstantData('const B<int>.named()',
         ConstantExpressionKind.CONSTRUCTED,
         type: 'A<int>',
         fields: const {
           'field(A#field1)': '42',
-        }),*/
+        }),
   ]),
 ];
 
 main() {
   asyncTest(() => Future.forEach(DATA, testData));
 }
 
 Future testData(TestData data) {
   StringBuffer sb = new StringBuffer();
   sb.write('${data.declarations}\n');
@@ skipping 34 matching lines @@
           String expression = instanceFields[field].getText();
           String expected = data.fields[name];
           Expect.equals(expected, expression,
               "Unexpected field expression ${expression} for field '$name' in "
               "contant `${constant.getText()}`, expected '${expected}'.");
         });
       }
     });
   });
 }