Run analyzer_cli asynchronously.

pkg/analyzer_cli/test/embedder_test.dart

 // Copyright (c) 2016, 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:analyzer/src/dart/sdk/sdk.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer_cli/src/driver.dart' show Driver, errorSink, outSink;
 import 'package:path/path.dart' as path;
 import 'package:test/test.dart';
 
 import 'utils.dart';
 
 main() {
   group('_embedder.yaml', () {
     StringSink savedOutSink, savedErrorSink;
     int savedExitCode;
 
     setUp(() {
       savedOutSink = outSink;
       savedErrorSink = errorSink;
       savedExitCode = exitCode;
       outSink = new StringBuffer();
       errorSink = new StringBuffer();
     });
+
     tearDown(() {
       outSink = savedOutSink;
       errorSink = savedErrorSink;
       exitCode = savedExitCode;
     });
 
-    test('resolution', wrap(() {
+    test('resolution', wrap(() async {
       var testDir = path.join(testDirectory, 'data', 'embedder_client');
-      new Driver().start([
+      await new Driver().start([
         '--packages',
         path.join(testDir, '_packages'),
         path.join(testDir, 'embedder_yaml_user.dart')
       ]);
 
       expect(exitCode, 0);
       expect(outSink.toString(), contains('No issues found'));
     }));
 
-    test('sdk setup', wrap(() {
+    test('sdk setup', wrap(() async {
       var testDir = path.join(testDirectory, 'data', 'embedder_client');
       Driver driver = new Driver();
-      driver.start([
+      await driver.start([
         '--packages',
         path.join(testDir, '_packages'),
         path.join(testDir, 'embedder_yaml_user.dart')
       ]);
 
       DartSdk sdk = driver.sdk;
       expect(sdk, new isInstanceOf<FolderBasedDartSdk>());
       expect((sdk as FolderBasedDartSdk).useSummary, isFalse);
     }));
   });
 }
 
 /// Wrap a function call to dump stdout and stderr in case of an exception.
 Function wrap(Function f) {
-  return () {
+  return () async {
     try {
-      f();
+      await f();
     } catch (e) {
       if (outSink.toString().isNotEmpty) {
         print('stdout:');
         print(outSink);
       }
       if (errorSink.toString().isNotEmpty) {
         print('stderr:');
         print(errorSink);
       }
       throw e;
     }
   };
 }