add a new 'dart bin/report.dart contributors' command (#311)

- add a new 'dart bin/report.dart contributors' command

This will collect the top contributors to dart-lang git repos from the
last 365 days.

---

- [x] I’ve reviewed the contributor guide and applied the relevant
portions to this PR.

<details>
  <summary>Contribution guidelines:</summary><br>

- See our [contributor
guide](https://github.com/dart-lang/.github/blob/main/CONTRIBUTING.md)
for general expectations for PRs.
- Larger or significant changes should be discussed in an issue before
creating a PR.
- Contributions to our repos should follow the [Dart style
guide](https://dart.dev/guides/language/effective-dart) and use `dart
format`.
- Most changes should add an entry to the changelog and may need to [rev
the pubspec package
version](https://github.com/dart-lang/sdk/blob/main/docs/External-Package-Maintenance.md#making-a-change).
- Changes to packages require [corresponding
tests](https://github.com/dart-lang/.github/blob/main/CONTRIBUTING.md#Testing).

Note that many Dart repos have a weekly cadence for reviewing PRs -
please allow for some latency before initial review feedback.
</details>

pkgs/repo_manage/lib/contributors.dart

@@ -0,0 +1,270 @@
+// Copyright (c) 2024, 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:convert';
+
+import 'package:github/github.dart';
+import 'package:graphql/client.dart';
+
+import 'src/common.dart';
+
+class ContributorsCommand extends ReportCommand {
+  ContributorsCommand()
+      : super(
+            'contributors',
+            'Run a report on repo contributors.\n'
+                'Defaults to the last 365 days.') {
+    argParser
+      ..addFlag(
+        'dart-lang',
+        negatable: false,
+        help: 'Return stats for all dart-lang repos (otherwise, this defaults '
+            'to the main Dart and Flutter repos).',
+      )
+      ..addFlag(
+        'monthly',
+        negatable: false,
+        help: 'Last 30 days.',
+      );
+  }
+
+  @override
+  Future<int> run() async {
+    final args = argResults!;
+    final byMonth = args['monthly'] as bool;
+    final allDartLang = args['dart-lang'] as bool;
+
+    late final DateTime firstReportingDay;
+
+    if (byMonth) {
+      final now = DateTime.now();
+      firstReportingDay = now.subtract(const Duration(days: 31));
+    } else {
+      // by year
+      final now = DateTime.now();
+      firstReportingDay = now.subtract(const Duration(days: 365));
+    }
+
+    var repos = noteableRepos
+        .map(RepositorySlug.full)
+        .where((repo) => repo.owner == 'dart-lang')
+        .toList();
+
+    if (allDartLang) {
+      repos = (await getReposForOrg('dart-lang')).map((r) => r.slug()).toList();
+    }
+
+    print('Reporting from ${iso8601String(firstReportingDay)}...');
+
+    final aggregates = <String, List<Commit>>{};
+
+    for (final repo in repos) {
+      final commits = await queryCommits(repo: repo, from: firstReportingDay);
+
+      print('$repo: ${commits.length} commits');
+
+      for (final commit in commits) {
+        aggregates.putIfAbsent(commit.user, () => []).add(commit);
+      }
+    }
+
+    print('');
+
+    final contributors = <Contributor>[];
+
+    for (final entry in aggregates.entries) {
+      contributors.add(
+        Contributor(github: entry.key, count: entry.value.length),
+      );
+    }
+
+    contributors.sort((a, b) {
+      return b.count - a.count;
+    });
+
+    for (var i = 0; i < contributors.length; i++) {
+      final contributor = contributors[i];
+      print('[$i] @${contributor.github}: ${contributor.count} commits');
+    }
+
+    return 0;
+  }
+
+  Future<List<Commit>> queryCommits({
+    required RepositorySlug repo,
+    required DateTime from,
+  }) async {
+    var result = await query(
+      QueryOptions(document: gql(commitQueryString(repo: repo, from: from))),
+    );
+    if (result.hasException) throw result.exception!;
+
+    final commits = <Commit>[];
+
+    while (true) {
+      if (result.hasException) throw result.exception!;
+
+      commits.addAll(_getCommitsFromResult(result));
+
+      final pageInfo = _pageInfoFromResult(result);
+      final hasNextPage = (pageInfo['hasNextPage'] as bool?) ?? false;
+
+      if (hasNextPage) {
+        final endCursor = pageInfo['endCursor'] as String?;
+        result = await query(
+          QueryOptions(
+            document: gql(
+              commitQueryString(repo: repo, from: from, endCursor: endCursor),
+            ),
+          ),
+        );
+      } else {
+        break;
+      }
+    }
+
+    return commits;
+  }
+}
+
+Iterable<Commit> _getCommitsFromResult(QueryResult result) {
+  // ignore: avoid_dynamic_calls
+  final history = result.data!['repository']['defaultBranchRef']['target']
+      ['history'] as Map;
+  var edges = (history['edges'] as List).cast<Map>();
+
+  return edges.map<Commit>((Map edge) {
+    var node = edge['node'] as Map<String, dynamic>;
+    return Commit.fromQuery(node);
+  });
+}
+
+Map<String, dynamic> _pageInfoFromResult(QueryResult result) {
+  // pageInfo {
+  //   endCursor
+  //   startCursor
+  //   hasNextPage
+  //   hasPreviousPage
+  // }
+
+  // ignore: avoid_dynamic_calls
+  final history = result.data!['repository']['defaultBranchRef']['target']
+      ['history'] as Map;
+
+  return (history['pageInfo'] as Map).cast();
+}
+
+String commitQueryString({
+  required RepositorySlug repo,
+  required DateTime from,
+  String? endCursor,
+}) {
+  final since = from.toIso8601String();
+  final cursor = endCursor == null ? '' : ', after: "$endCursor"';
+
+  // https://docs.github.com/en/graphql/reference/objects#commit
+  return '''{
+      repository(owner: "${repo.owner}", name: "${repo.name}") {
+        defaultBranchRef {
+          target {
+            ... on Commit {
+              history(first: 100, since: "$since" $cursor) {
+                edges {
+                  node {
+                    oid
+                    messageHeadline
+                    committedDate
+                    author {
+                      user {
+                        login
+                      }
+                    }
+                    committer {
+                      user {
+                        login
+                      }
+                    }
+                  }
+                }
+                pageInfo {
+                  endCursor
+                  startCursor
+                  hasNextPage
+                  hasPreviousPage
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+''';
+}
+
+class Commit implements Comparable<Commit> {
+  final String oid;
+  final String message;
+  final String user;
+  final DateTime committedDate;
+
+  Commit({
+    required this.oid,
+    required this.message,
+    required this.user,
+    required this.committedDate,
+  });
+
+  factory Commit.fromQuery(Map<String, dynamic> node) {
+    var oid = node['oid'] as String;
+    var messageHeadline = node['messageHeadline'] as String;
+    // ignore: avoid_dynamic_calls
+    var user = (node['author']['user'] ?? node['committer']['user']) as Map?;
+    var login = user == null ? '' : user['login'] as String;
+    // 2021-07-23T18:37:57Z
+    var committedDate = node['committedDate'] as String;
+
+    if (login.isEmpty) {
+      final json = jsonEncode(node);
+      print('[$json]');
+    }
+
+    return Commit(
+      oid: oid,
+      message: messageHeadline,
+      user: login,
+      committedDate: DateTime.parse(committedDate),
+    );
+  }
+
+  @override
+  int compareTo(Commit other) {
+    return other.committedDate.compareTo(committedDate);
+  }
+
+  @override
+  String toString() => '${oid.substring(0, 8)} $_shortDate $user $message';
+
+  String get _shortDate => committedDate.toIso8601String().substring(0, 10);
+}
+
+class PageInfo {
+  final String endCursor;
+  final bool hasNextPage;
+
+  PageInfo({required this.endCursor, required this.hasNextPage});
+
+  static PageInfo parse(Map<String, dynamic> json) {
+    return PageInfo(
+      endCursor: json['endCursor'] as String,
+      hasNextPage: json['hasNextPage'] as bool,
+    );
+  }
+}
+
+class Contributor {
+  final String github;
+  final int count;
+
+  Contributor({required this.github, required this.count});
+}

pkgs/repo_manage/lib/src/common.dart

@@ -10,6 +10,7 @@ import 'package:github/github.dart';
 import 'package:graphql/client.dart';
 
 import '../branches.dart';
+import '../contributors.dart';
 import '../issue_transfer.dart';
 import '../labels.dart';
 import '../labels_update.dart';
@@ -79,10 +80,11 @@ class ReportCommandRunner extends CommandRunner<int> {
       : super('report',
             'Run various reports on Dart and Flutter related repositories.') {
     addCommand(BranchesCommand());
+    addCommand(ContributorsCommand());
     addCommand(LabelsCommand());
     addCommand(LabelsUpdateCommand());
-    addCommand(WeeklyCommand());
     addCommand(TransferIssuesCommand());
+    addCommand(WeeklyCommand());
   }
 
   GitHub get github =>
@@ -147,11 +149,12 @@ class RepoInfo {
 // These are monorepos, high-traffic repos, or otherwise noteable repos.
 final List<String> noteableRepos = [
   'dart-lang/build',
+  'dart-lang/core',
   'dart-lang/ecosystem',
   'dart-lang/ffi',
   'dart-lang/http',
+  'dart-lang/i18n',
   'dart-lang/language',
-  'dart-lang/linter',
   'dart-lang/native',
   'dart-lang/pub',
   'dart-lang/sdk',