Migrated test block 218 to Dart 2.0.

tests/lib/mirrors/constructor_optional_args_test.dart

-// Copyright (c) 2016, 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 test.constructor_test;
-
-@MirrorsUsed(targets: const [A])
-import 'dart:mirrors';
-import 'package:expect/expect.dart';
-
-class A {
-  factory A([x, y]) = B;
-  factory A.more([x, y]) = B.more;
-  factory A.oneMore(x, [y]) = B.more;
-}
-
-class B implements A {
-  final _x, _y, _z;
-
-  B([x = 'x', y = 'y'])
-      : _x = x,
-        _y = y,
-        _z = null;
-
-  B.more([x = 'x', y = 'y', z = 'z'])
-      : _x = x,
-        _y = y,
-        _z = z;
-
-  toString() => 'B(x=$_x, y=$_y, z=$_z)';
-}
-
-main() {
-  var d1 = new A(1);
-  Expect.equals('B(x=1, y=y, z=null)', '$d1', 'direct 1');
-
-  var d2 = new A.more(1);
-  Expect.equals('B(x=1, y=y, z=z)', '$d2', 'direct 2');
-
-  ClassMirror cm = reflectClass(A);
-
-  var v1 = cm.newInstance(const Symbol(''), []).reflectee;
-  var v2 = cm.newInstance(const Symbol(''), [1]).reflectee;
-  var v3 = cm.newInstance(const Symbol(''), [2, 3]).reflectee;
-
-  Expect.equals('B(x=x, y=y, z=null)', '$v1', 'unnamed 1');
-  Expect.equals('B(x=1, y=y, z=null)', '$v2', 'unnamed 2');
-  Expect.equals('B(x=2, y=3, z=null)', '$v3', 'unnamed 3');
-
-  var m1 = cm.newInstance(const Symbol('more'), []).reflectee;
-  var m2 = cm.newInstance(const Symbol('more'), [1]).reflectee;
-  var m3 = cm.newInstance(const Symbol('more'), [2, 3]).reflectee;
-
-  Expect.equals('B(x=x, y=y, z=z)', '$m1', 'more 1');
-  Expect.equals('B(x=1, y=y, z=z)', '$m2', 'more 2');
-  Expect.equals('B(x=2, y=3, z=z)', '$m3', 'more 3');
-
-  var o1 = cm.newInstance(const Symbol('oneMore'), [1]).reflectee;
-  var o2 = cm.newInstance(const Symbol('oneMore'), [2, 3]).reflectee;
-
-  Expect.equals('B(x=1, y=y, z=z)', '$o1', 'oneMore one arg');
-  Expect.equals('B(x=2, y=3, z=z)', '$o2', 'oneMore two args');
-}