Add a 'bot.dart' executable to the gardening tools.

tools/gardening/bin/current_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 test results for all build bots in [buildGroups] for tests
 /// that mention one of the test names given as argument.
 ///
 /// The results are currently pulled from the second to last build since the
 /// last build might not have completed yet.
 
-import 'dart:math';
+import 'dart:async';
+import 'dart:math' hide log;
 import 'dart:io';
 
 import 'package:args/args.dart';
 import 'package:gardening/src/buildbot_data.dart';
 import 'package:gardening/src/buildbot_loading.dart';
 import 'package:gardening/src/buildbot_structures.dart';
 import 'package:gardening/src/util.dart';
 
+void help(ArgParser argParser) {
+  print('Displays the current status of specific tests on the buildbot');
+  print('Only prints output for failing tests.');
+  print('The test-names may be fully qualified (such as in ');
+  print('"pkg/front_end/test/token_test") or just be a substring of the fully');
+  print(' qualified name.');
+  print('Usage: current_summary [options] <test-name1> [<test-name2> ...]');
+  print('where options are:');
+  print(argParser.usage);
+}
+
 main(List<String> args) async {
   ArgParser argParser = createArgParser();
   ArgResults argResults = argParser.parse(args);
   processArgResults(argResults);
-  if (argResults.rest.length == 0) {
-    print('Usage: current_summary [options] <test-name1> [<test-name2> ...]');
-    print('where options are:');
-    print(argParser.usage);
+  if (argResults.rest.length == 0 || argResults['help']) {
+    help(argParser);
+    if (argResults['help']) return;
     exit(1);
   }
   int maxStatusWidth = 0;
   int maxConfigWidth = 0;
 
   HttpClient client = new HttpClient();
   Map<String, Map<BuildUri, TestStatus>> resultMap =
       <String, Map<BuildUri, TestStatus>>{};
   for (BuildGroup group in buildGroups) {
     // TODO(johnniwinther): Support reading a partially completed shard, i.e.
     // use build number `-1`.
-    for (BuildUri buildUri in group.createUris(-2)) {
-      print('Reading $buildUri');
-      BuildResult buildResult = await readBuildResult(client, buildUri);
+    var resultFutures = group.createUris(-2).map((uri) {
+      log('Fetching $uri');
+      return readBuildResult(client, uri);
+    }).toList();
+    var results = await Future.wait(resultFutures);
+    for (BuildResult buildResult in results) {
+      bool havePrintedUri = false;
+      var buildUri = buildResult.buildUri;
+      if (argResults['verbose']) {
+        havePrintedUri = true;
+        print('Reading $buildUri');
+      }
       for (TestStatus testStatus in buildResult.results) {
         String testName = testStatus.config.testName;
         for (String arg in argResults.rest) {
           if (testName.contains(arg) || arg.contains(testName)) {
+            if (!havePrintedUri) {
+              havePrintedUri = true;
+              print("$buildUri:");
+            }
             resultMap.putIfAbsent(testName, () => {})[buildUri] = testStatus;
             maxStatusWidth = max(maxStatusWidth, testStatus.status.length);
             maxConfigWidth =
                 max(maxConfigWidth, testStatus.config.configName.length);
           }
         }
       }
     }
   }
   print('');
   resultMap.forEach((String testName, Map<BuildUri, TestStatus> statusMap) {
     print(testName);
     statusMap.forEach((BuildUri buildUri, TestStatus status) {
       print('  ${padRight(status.status, maxStatusWidth)}: '
           '${padRight(status.config.configName, maxConfigWidth)} '
           '${buildUri.shortBuildName}');
     });
   });
   client.close();
 }