Migrated test block 20 to Dart 2.0.

tests/corelib/regexp/non-bmp_test.dart

-// Copyright (c) 2014, the Dart project authors. All rights reserved.
-// Copyright 2013 the V8 project authors. All rights reserved.
-// Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions
-// are met:
-// 1.  Redistributions of source code must retain the above copyright
-//     notice, this list of conditions and the following disclaimer.
-// 2.  Redistributions in binary form must reproduce the above copyright
-//     notice, this list of conditions and the following disclaimer in the
-//     documentation and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
-// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
-// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
-// ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-import 'v8_regexp_utils.dart';
-import 'package:expect/expect.dart';
-
-void main() {
-  description('Tests that regular expressions treat non-BMP characters as two separate characters. ' +
-      'From a Unicode correctness point of view this is wrong, but it is what other browsers do. ' +
-      'And given that we store strings as UTF-16, it is also more efficient to implement. ' +
-      'Also test some other cases related to UTF-8 and UTF-16.');
-
-  var surrogatePair =
-      new String.fromCharCode(0xD800) + new String.fromCharCode(0xDC00);
-
-  assertEquals(new RegExp(r".").firstMatch(surrogatePair).group(0).length, 1);
-  assertEquals(new RegExp(r"\D").firstMatch(surrogatePair).group(0).length, 1);
-  assertEquals(new RegExp(r"\S").firstMatch(surrogatePair).group(0).length, 1);
-  assertEquals(new RegExp(r"\W").firstMatch(surrogatePair).group(0).length, 1);
-  assertEquals(
-      new RegExp(r"[^x]").firstMatch(surrogatePair).group(0).length, 1);
-
-  assertEquals(
-      new RegExp(r".{1,2}")
-          .firstMatch("!!" + new String.fromCharCode(0xA1))
-          .group(0)
-          .length,
-      2);
-  shouldBeNull(new RegExp(r".").firstMatch(""));
-}