Reapply "Port regexp tests from V8 to Dart."

tests/corelib/regexp/backreferences_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("Test to ensure correct behaviour when using backreferences in a RegExp");
+
+  shouldBeTrue(new RegExp(r"(...)\1$").hasMatch('abcabc'));
+  shouldBeFalse(new RegExp(r"(...)\1$").hasMatch('abcdef'));
+  shouldBeFalse(new RegExp(r"(...)\2$").hasMatch('abcabc'));
+  shouldBeFalse(new RegExp(r"(...)\2$").hasMatch('abc'));
+  shouldBeTrue(new RegExp(r"\1(...)$").hasMatch('abcabc'));
+  shouldBeTrue(new RegExp(r"\1(...)$").hasMatch('abcdef'));
+  shouldBeFalse(new RegExp(r"\2(...)$").hasMatch('abcabc'));
+  shouldBeFalse(new RegExp(r"\2(...)$").hasMatch('abc'));
+  shouldBeTrue(new RegExp(r"\1?(...)$").hasMatch('abc'));
+  shouldBeTrue(new RegExp(r"\1?(...)$").hasMatch('abc'));
+
+  var re = new RegExp(r"[^b]*((..)|(\2))+Sz", caseSensitive: false);
+
+  shouldBeFalse(re.hasMatch('axabcd'));
+  shouldBeTrue(re.hasMatch('axabcsz'));
+}