Use native async/await support in pub.

sdk/lib/_internal/pub_generated/test/transformer/does_not_run_a_transform_on_an_input_in_another_package_test.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.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 pub_tests;
-
-import '../descriptor.dart' as d;
-import '../test_pub.dart';
-import '../serve/utils.dart';
-
-main() {
-  initConfig();
-  withBarbackVersions("any", () {
-    integration("does not run a transform on an input in another package", () {
-      d.dir("foo", [d.pubspec({
-          "name": "foo",
-          "version": "0.0.1",
-          "transformers": ["foo/transformer"]
-        }),
-            d.dir(
-                "lib",
-                [
-                    d.file("transformer.dart", REWRITE_TRANSFORMER),
-                    d.file("foo.txt", "foo")])]).create();
-
-      d.dir(appPath, [d.appPubspec({
-          "foo": {
-            "path": "../foo"
-          }
-        }), d.dir("lib", [d.file("bar.txt", "bar")])]).create();
-
-      createLockFile('myapp', sandbox: ['foo'], pkg: ['barback']);
-
-      pubServe();
-      requestShould404("packages/myapp/bar.out");
-      endPubServe();
-    });
-  });
-}