Use package:testing for tools/gardening

tools/gardening/bin/status_summary.dart

 // Copyright (c) 2017, 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.
 
 /// Collects the configurations for all status files in the 'tests' folder that
 /// mention one of the test names given as argument.
 
 import 'dart:async';
 import 'dart:math' hide log;
 import 'dart:io';
 
 import 'package:args/args.dart';
 import 'package:gardening/src/util.dart';
 
 void help(ArgParser argParser) {
   print('Prints all status-file entries for the given tests.');
   print('The test-names must be a substring (or full match) of the lines in ');
   print('the status file. They can not be fully qualified');
   print('Usage: status_summary [options] <test-name1> [<test-name2> ...]');
   print('where options are:');
   print(argParser.usage);
 }
 
-main(List<String> args) async {
+Future main(List<String> args) async {
   ArgParser argParser = createArgParser();
   ArgResults argResults = argParser.parse(args);
   processArgResults(argResults);
   if (argResults.rest.length == 0 || argResults['help']) {
     help(argParser);
     if (argResults['help']) return;
     exit(1);
   }
   int maxStatusWidth = 0;
   int maxConfigWidth = 0;
@@ skipping 93 matching lines @@
   /// The status of the entry, e.g. `Pass, Slow`.
   final String status;
 
   /// The comment after the status, if any.
   final String comment;
 
   StatusEntry(this.config, this.status, this.comment);
 
   String toString() => '$status $config $comment';
 }