- Add new test for regex

corelib/src/RegExp5Test.dart

+// Copyright (c) 2011, 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.
+// Dart test for testing regular expressions in Dart.
+
+main() {
+  String str = "";
+  try {
+    RegExp ex = new RegExp(str);
+  } catch (Exception e) {
+    if (!(e is NullPointerException)) {
+      Expect.fail("Expected: NullPointerException" + " got: ${e}");
+    }
+  }
+  Expect.isFalse(new RegExp(@"^\w+$").hasMatch(str));
+  Match fm = new RegExp(@"^\w+$").firstMatch(str);
+  Expect.equals(null, fm);
+
+  Iterable<Match> am = new RegExp(@"^\w+$").allMatches(str);
+  Expect.isFalse(am.iterator().hasNext());
+
+  Expect.equals(null, new RegExp(@"^\w+$").stringMatch(str));
+}