Sharing metatest logic between unittest and scheduled_test

pkg/scheduled_test/test/descriptor/nothing_test.dart

 // Copyright (c) 2013, 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.
 
 import 'dart:io';
 
 import 'package:path/path.dart' as path;
 import 'package:scheduled_test/descriptor.dart' as d;
 import 'package:scheduled_test/scheduled_test.dart';
 
-import '../metatest.dart';
+import 'package:metatest/metatest.dart';
 import 'utils.dart';
 
-void main(_, message) {
+void main() => initTests(_test);
+
+void _test(message) {
   initMetatest(message);
 
   setUpTimeout();
 
   expectTestsPass("nothing().create() does nothing", () {
     test('test', () {
       scheduleSandbox();
 
       d.nothing('foo').create();
 
@@ skipping 45 matching lines @@
       new Link(path.join(sandbox, 'link')).createSync('nonexistent');
     });
     d.nothing('link').validate();
   }, (errors) {
     expect(errors.single, new isInstanceOf<ScheduleError>());
     expect(errors.single.error.toString(),
         matches(r"^Expected nothing to exist at '[^']+[\\/]link', but found "
             r"a link\.$"));
   });
 }