Migrated test block 19 to Dart 2.0.

tests/corelib_strong/reg_exp4_test.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.
-
-import "package:expect/expect.dart";
-
-main() {
-  try {
-    RegExp ex = new RegExp(null);
-    Expect.fail("Expected: ArgumentError got: no exception");
-  } catch (ex) {
-    if (!(ex is ArgumentError)) {
-      Expect.fail("Expected: ArgumentError got: ${ex}");
-    }
-  }
-  try {
-    new RegExp(r"^\w+$").hasMatch(null);
-    Expect.fail("Expected: ArgumentError got: no exception");
-  } catch (ex) {
-    if (!(ex is ArgumentError)) {
-      Expect.fail("Expected: ArgumentError got: ${ex}");
-    }
-  }
-  try {
-    new RegExp(r"^\w+$").firstMatch(null);
-    Expect.fail("Expected: ArgumentError got: no exception");
-  } catch (ex) {
-    if (!(ex is ArgumentError)) {
-      Expect.fail("Expected: ArgumentError got: ${ex}");
-    }
-  }
-  try {
-    new RegExp(r"^\w+$").allMatches(null);
-    Expect.fail("Expected: ArgumentError got: no exception");
-  } catch (ex) {
-    if (!(ex is ArgumentError)) {
-      Expect.fail("Expected: ArgumentError got: ${ex}");
-    }
-  }
-  try {
-    new RegExp(r"^\w+$").stringMatch(null);
-    Expect.fail("Expected: ArgumentError got: no exception");
-  } catch (ex) {
-    if (!(ex is ArgumentError)) {
-      Expect.fail("Expected: ArgumentError got: ${ex}");
-    }
-  }
-}