Find the system locale from the browser or OS

pkg/intl/test/find_default_locale_standalone_test.dart

+// Copyright (c) 2012, 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('find_default_locale_browser_test');
+
+#import('../intl.dart');
+#import('../intl_standalone.dart');
+#import('../../unittest/unittest.dart');
+
+main() {
+  test("Find system locale standalone", () {
+    // TODO (alanknight): This only verifies that we found some locale. We
+    // should find a way to force the system locale before the test is run
+    // and then verify that it's actually the correct value.
+    Intl.systemLocale = "xx_YY";
+    var callback = expectAsync1(verifyLocale);
+    findSystemLocale().then(callback);
+    });
+}
+
+verifyLocale(_) {
+  expect(Intl.systemLocale, isNot(equals("xx_YY")));
+  var pattern = new RegExp(@"\w\w_[A-Z0-9]+");
+  var match = pattern.hasMatch(Intl.systemLocale);
+  expect(match, isTrue);
+}