Script finding the build bot group for a given shard.

tools/gardening/bin/create_shard_groups.dart

Index: tools/gardening/bin/create_shard_groups.dart
diff --git a/tools/gardening/bin/create_shard_groups.dart b/tools/gardening/bin/create_shard_groups.dart
new file mode 100644
index 0000000000000000000000000000000000000000..b54a87765d9bbee658cd2f64bb81426214729daf
--- /dev/null
+++ b/tools/gardening/bin/create_shard_groups.dart
@@ -0,0 +1,99 @@
+// 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.
+
+// Outputs source code for `part` used by `shard2group.dart`. Usage:
+// `dart bin/create_shard_groups.dart source.html >lib/src/shard_data.dart`.
+
+import 'dart:io';
+import 'dart:math' as math;
+
+const String groupsStartMark = r"<td class='DevStatus Alt first";
+const String groupsEndMark = r"<tr class='DevStatusSpacing'>";
+
+List<String> findGroups(List<String> source) {
+  List<String> result = <String>[];
+  bool started = false;
+  
+  for (String line in source) {
+    if (line.contains(groupsStartMark)) started = true;
+    if (started) {
+      if (line.contains(groupsEndMark)) break;
+      String trimmed = line.trim();
+      if (!trimmed.startsWith('<')) {
+        result.add(trimmed);
+      }
+    }
+  }
+  return result;
+}
+
+const String shardsStartMark = groupsEndMark;
+const String shardsEndMark = r"<td class='DevStatusBox";
+const String shardsGroupStartMark = r"<td class='DevSlave Alt";
+const String shardMark = '/builders/';
+
+List<List<String>> findShards(List<String> source) {
+  List<List<String>> result = <List<String>>[];
+  List<String> shardResult;
+  bool started = false;
+
+  for (String line in source) {
+    if (line.contains(shardsStartMark)) started = true;
+    if (started) {
+      if (line.contains(shardsEndMark)) break;
+      String trimmed = line.trim();
+      int buildersIndex = trimmed.indexOf(shardMark);
+      if (buildersIndex >= 0) {
+        int quoteIndex = trimmed.indexOf("'", buildersIndex);
+        if (quoteIndex >= 0) {
+          // Found a shard name, add it.
+          shardResult.add(trimmed.substring(
+              buildersIndex + shardMark.length, quoteIndex));
+        } else {
+          // Unexpected source formatting, skip.
+        }
+      } else if (trimmed.contains(shardsGroupStartMark)) {
+        // This is a group separator, switch to next sublist.
+        if (shardResult != null) result.add(shardResult);
+        shardResult = <String>[];
+      }
+    }
+  }
+  return result;  
+}
+
+main(List<String> args) {
+  if (args.length != 1) {
+    print('Usage: dart create_shard_groups.dart <darto-source-file>');
+    exit(1);
+  }
+
+  File dartoSourceFile = new File(args[0]);
+  List<String> dartoSource = dartoSourceFile.readAsLinesSync();
+
+  List<String> groups = findGroups(dartoSource);
+  List<String> shards = findShards(dartoSource);
+  int groupCount = math.min(groups.length, shards.length);
+
+  // Print the resulting Dart declaration.
+  print("""
+// 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.
+//
+// ----- Generated by create_shard_groups.dart, do not edit! -----
+
+part of gardening.shard2group;
+
+const Map<String, List<String>> shardGroups = const {
+""");
+  for (int i = 0; i < groupCount; i++) {
+    print("  '${groups[i]}': const <String>[");
+    for (List<String> shard in shards[i]) {
+      print("    '$shard',");
+    }
+    print("  ],");
+  }
+  print('};');
+}