Add tests for BuildGroup names

tools/gardening/test/buildbot_data_test.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.
+
+/// Checks that all active test steps in [buildGroups] can be read from http.
+
+import 'package:args/args.dart';
+import 'package:expect/expect.dart';
+import 'package:gardening/src/buildbot_data.dart';
+import 'package:gardening/src/buildbot_structures.dart';
+import 'package:gardening/src/client.dart';
+import 'package:gardening/src/util.dart';
+
+main(List<String> args) async {
+  ArgParser argParser = createArgParser();
+  ArgResults argResults = argParser.parse(args);
+  processArgResults(argResults);
+  bool useLogdog = argResults['logdog'];
+
+  BuildbotClient client =
+      useLogdog ? new LogdogBuildbotClient() : new HttpBuildbotClient();
+
+  List<String> failingUris = <String>[];
+  for (BuildGroup buildGroup in buildGroups) {
+    for (BuildSubgroup buildSubgroup in buildGroup.subgroups) {
+      if (!useLogdog && !buildSubgroup.isActive) continue;
+      List<BuildUri> buildUris =
+          buildSubgroup.createUris(client.mostRecentBuildNumber);
+      for (BuildUri buildUri in buildUris) {
+        BuildResult result = await client.readResult(buildUri);
+        if (result == null) {
+          failingUris.add('$buildUri');
+        }
+      }
+    }
+  }
+  // TODO(johnniwinther): Find out why these steps cannot be read.
+  Expect.setEquals([
+    '/builders/precomp-linux-debug-x64-be/builds/-2/steps/vm tests',
+    '/builders/pkg-mac10.11-release-be/builds/-2/'
+        'steps/third_party/pkg_tested unit tests',
+    '/builders/pkg-linux-release-be/builds/-2/steps/'
+        'third_party/pkg_tested unit tests',
+    '/builders/pkg-win7-release-be/builds/-2/steps/'
+        'third_party/pkg_tested unit tests',
+  ], failingUris);
+
+  client.close();
+}