Revert "Use native async/await support in pub."

sdk/lib/_internal/pub_generated/test/preprocess_test.dart

 // Copyright (c) 2014, 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 pub.test.preprocess_test;
 
 import 'package:pub_semver/pub_semver.dart';
 import 'package:unittest/unittest.dart';
 
 import '../lib/src/preprocess.dart';
@@ skipping 230 matching lines @@
     test("disallows insert directive without space", () {
       expect(() => _preprocess('//>foo'), throwsFormatException);
     });
 
     group("if", () {
       test("disallows if with no arguments", () {
         expect(() => _preprocess('//# if\n//# end'), throwsFormatException);
       });
 
       test("disallows if with no package", () {
-        expect(() => _preprocess('//# if <=1.0.0\n//# end'),
+        expect(
+            () => _preprocess('//# if <=1.0.0\n//# end'),
             throwsFormatException);
       });
 
       test("disallows invalid version constraint", () {
-        expect(() => _preprocess('//# if barback >=1.0\n//# end'),
+        expect(
+            () => _preprocess('//# if barback >=1.0\n//# end'),
             throwsFormatException);
       });
 
       test("disallows dangling end", () {
-        expect(() => _preprocess('//# end'),
+        expect(() => _preprocess('//# end'), throwsFormatException);
+      });
+
+      test("disallows if without end", () {
+        expect(
+            () => _preprocess('//# if barback >=1.0.0'),
             throwsFormatException);
       });
 
-      test("disallows if without end", () {
-        expect(() => _preprocess('//# if barback >=1.0.0'),
-            throwsFormatException);
-      });
-
       test("disallows nested if", () {
         expect(() => _preprocess('''
 //# if barback >=1.0.0
 //# if barback >= 1.5.0
 //# end
 //# end
-'''),
-            throwsFormatException);
+'''), throwsFormatException);
       });
     });
 
     group("else", () {
       test("disallows else without if", () {
         expect(() => _preprocess('//# else\n//# end'), throwsFormatException);
       });
 
       test("disallows else without end", () {
-        expect(() => _preprocess('//# if barback >=1.0.0\n//# else'),
+        expect(
+            () => _preprocess('//# if barback >=1.0.0\n//# else'),
             throwsFormatException);
       });
 
       test("disallows else with an argument", () {
         expect(() => _preprocess('''
 //# if barback >=1.0.0
 //# else barback <0.5.0
 //# end
 '''), throwsFormatException);
       });
     });
   });
 }
 
-String _preprocess(String input) =>
-    preprocess(input, {'barback': new Version.parse("1.2.3")}, 'source/url');
+String _preprocess(String input) => preprocess(input, {
+  'barback': new Version.parse("1.2.3")
+}, 'source/url');