an implementation of the init command

mono_repo/README.md

@@ -34,6 +34,7 @@ Global options:
 Available commands:
   check       Check the state of the repository.
   generate    Generates the CI configuration for child packages.
+  init        Scaffold a new mono repo.
   presubmit   Run the CI presubmits locally.
   pub         Run `pub get` or `pub upgrade` against all packages.
   travis      (Deprecated, use `generate`) Configure Travis-CI for child packages.

mono_repo/lib/src/commands/init.dart

@@ -0,0 +1,105 @@
+// Copyright (c) 2020, 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:io';
+
+import 'package:args/command_runner.dart';
+import 'package:io/ansi.dart';
+import 'package:path/path.dart' as p;
+
+const _pubspecFileName = 'pubspec.yaml';
+const _pkgCfgFileName = 'mono_pkg.yaml';
+const _repoCfgFileName = 'mono_repo.yaml';
+const _recursiveScanFlag = 'recursive';
+
+const _repoCfgContents = r'''
+# See with https://github.com/dart-lang/mono_repo for details on this file
+self_validate: analyze_and_format
+
+github:
+  # Setting just `cron` keeps the defaults for `push` and `pull_request`
+  cron: '0 0 * * 0'
+  on_completion:
+    - name: "Notify failure"
+      runs-on: ubuntu-latest
+      # Run only if other jobs have failed and this is a push or scheduled build.
+      if: (github.event_name == 'push' || github.event_name == 'schedule') && failure()
+      steps:
+        - run: >
+            curl -H "Content-Type: application/json" -X POST -d \
+              "{'text':'Build failed! ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID}'}" \
+              "${CHAT_WEBHOOK_URL}"
+          env:
+            CHAT_WEBHOOK_URL: ${{ secrets.BUILD_AND_TEST_TEAM_CHAT_WEBHOOK_URL }}
+
+merge_stages:
+- analyze_and_format
+''';
+
+const _pkgCfgContents = r'''
+dart:
+- dev
+- stable
+
+os:
+- linux
+
+stages:
+- analyze_and_format:
+  - dartanalyzer: --fatal-infos --fatal-warnings .
+  - dartfmt: sdk
+- unit_test:
+  - test:
+''';
+
+class InitCommand extends Command<void> {
+  @override
+  String get name => 'init';
+
+  @override
+  String get description => 'Scaffold a new mono repo.';
+
+  @override
+  void run() => scaffold(p.current, globalResults[_recursiveScanFlag] as bool);
+}
+
+void scaffold(String rootDir, bool recursive) {
+  configureDirectory(rootDir, recursive: recursive);
+}
+
+void configureDirectory(String rootDir,
+    {String currentDir, bool recursive = false}) {
+  currentDir ??= rootDir;
+
+  if (currentDir == rootDir) {
+    final repoCfgPath = p.join(rootDir, _repoCfgFileName);
+    if (!File(repoCfgPath).existsSync()) {
+      File(repoCfgPath).writeAsStringSync(_repoCfgContents);
+      print(styleBold.wrap('Added $_repoCfgFileName to $rootDir'));
+    } else {
+      print(yellow.wrap('$_repoCfgFileName already present in $rootDir.'));
+    }
+  } else {
+    final pkgCfgPath = p.join(currentDir, _pkgCfgFileName);
+    final pubspecPath = p.join(currentDir, _pubspecFileName);
+
+    if (File(pubspecPath).existsSync()) {
+      if (!File(pkgCfgPath).existsSync()) {
+        File(pkgCfgPath).writeAsStringSync(_pkgCfgContents);
+        print(styleBold.wrap('Added $_pkgCfgFileName to $currentDir'));
+      } else {
+        print(yellow.wrap('$_pkgCfgFileName already present in $currentDir'));
+      }
+    }
+  }
+
+  final subdirs =
+      Directory(currentDir).listSync().whereType<Directory>().toList();
+  for (var subdir in subdirs) {
+    if (recursive || currentDir == rootDir) {
+      configureDirectory(rootDir,
+          currentDir: subdir.path, recursive: recursive);
+    }
+  }
+}

mono_repo/lib/src/runner.dart

@@ -9,6 +9,7 @@ import 'package:args/command_runner.dart';
 
 import 'commands/check.dart';
 import 'commands/generate.dart';
+import 'commands/init.dart';
 import 'commands/mono_repo_command.dart';
 import 'commands/presubmit.dart';
 import 'commands/pub.dart';
@@ -19,6 +20,7 @@ final commands = List<Command<void>>.unmodifiable(
   [
     CheckCommand(),
     GenerateCommand(),
+    InitCommand(),
     PresubmitCommand(),
     PubCommand(),
     TravisCommand(),

mono_repo/test/init_command_test.dart

@@ -0,0 +1,32 @@
+import 'dart:io';
+
+import 'package:path/path.dart' as p;
+import 'package:test/test.dart';
+import 'package:test_descriptor/test_descriptor.dart' as d;
+
+import 'package:mono_repo/src/commands/init.dart';
+
+void main() {
+  const repoCfgFileName = 'mono_repo.yaml';
+  const pkgCfgFileName = 'mono_pkg.yaml';
+
+  test('scaffold a new mono repo', () async {
+    await d.dir('top_level', [
+      d.dir('package1', [d.file('pubspec.yaml')]),
+      d.dir('package2', [d.file('pubspec.yaml')])
+    ]).create();
+    final rootDirectory = '${d.sandbox}/top_level';
+    final package1Directory = '${d.sandbox}/top_level/package1';
+    final package2Directory = '${d.sandbox}/top_level/package2';
+
+    final repoCfg = p.join(rootDirectory, repoCfgFileName);
+    final pkg1Cfg = p.join(package1Directory, pkgCfgFileName);
+    final pkg2Cfg = p.join(package2Directory, pkgCfgFileName);
+    scaffold(rootDirectory, false);
+    expect(
+        File(repoCfg).existsSync() &&
+            File(pkg1Cfg).existsSync() &&
+            File(pkg2Cfg).existsSync(),
+        equals(true));
+  });
+}

mono_repo/test/mono_repo_test.dart

@@ -43,6 +43,7 @@ Global options:
 Available commands:
   check       Check the state of the repository.
   generate    Generates the CI configuration for child packages.
+  init        Scaffold a new mono repo.
   presubmit   Run the CI presubmits locally.
   pub         Run `pub get` or `pub upgrade` against all packages.
   travis      (Deprecated, use `generate`) Configure Travis-CI for child packages.