Code formatter transform for empty constructor bodys (a la Style guide).

pkg/analyzer_experimental/test/services/formatter_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.
 
 import 'package:unittest/unittest.dart';
 
 import 'package:analyzer_experimental/src/generated/scanner.dart';
 import 'package:analyzer_experimental/src/services/formatter_impl.dart';
 import 'package:analyzer_experimental/src/services/writer.dart';
 
@@ skipping 620 matching lines @@
           '}\n',
           'class X {\n'
           '  var x, y;\n'
           '  X()\n'
           '      : x = 1,\n'
           '        y = 2;\n'
           '}\n'
       );
     });
 
+    test('CU (empty cons bodies)', () {
+      expectCUFormatsTo(
+          'class A {\n'
+          '  A() {\n'
+          '  }\n'
+          '}\n',
+          'class A {\n'
+          '  A();\n'
+          '}\n',
+          transforms: true
+      );
+      expectCUFormatsTo(
+          'class A {\n'
+          '  A() {\n'
+          '  }\n'
+          '}\n',
+          'class A {\n'
+          '  A() {\n'
+          '  }\n'
+          '}\n',
+          transforms: false
+      );
+    });
+
     test('stmt', () {
       expectStmtFormatsTo(
          'if (true){\n'
          'if (true){\n'
          'if (true){\n'
          'return true;\n'
          '} else{\n'
          'return false;\n'
          '}\n'
          '}\n'
@@ skipping 370 matching lines @@
     expect(()=> expectStreamsEqual(tokenize(s1), tokenize(s2)),
     throwsA(new isInstanceOf<FormatterException>()));
 
 expectStreamsEqual(Token t1, Token t2) =>
     new TokenStreamComparator(null, t1, t2).verifyEquals();
 
 expectStreamsNotEqual(Token t1, Token t2) =>
     expect(() => new TokenStreamComparator(null, t1, t2).verifyEquals(),
     throwsA(new isInstanceOf<FormatterException>()));
 
-expectCUFormatsTo(src, expected) =>
-    expect(formatCU(src).source, equals(expected));
+expectCUFormatsTo(src, expected, {transforms: true}) =>
+    expect(formatCU(src, options: new FormatterOptions(
+        codeTransforms: transforms)).source, equals(expected));
 
 expectStmtFormatsTo(src, expected, {transforms: true}) =>
     expect(formatStatement(src, options:
       new FormatterOptions(codeTransforms: transforms)), equals(expected));