Add pubspec convention checks (#3984)

script/tool/lib/src/pubspec_check_command.dart

@@ -0,0 +1,178 @@
+// Copyright 2013 The Flutter Authors. 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:async';
+
+import 'package:file/file.dart';
+import 'package:git/git.dart';
+import 'package:path/path.dart' as p;
+import 'package:pubspec_parse/pubspec_parse.dart';
+
+import 'common.dart';
+
+/// A command to enforce pubspec conventions across the repository.
+///
+/// This both ensures that repo best practices for which optional fields are
+/// used are followed, and that the structure is consistent to make edits
+/// across multiple pubspec files easier.
+class PubspecCheckCommand extends PluginCommand {
+  /// Creates an instance of the version check command.
+  PubspecCheckCommand(
+    Directory packagesDir,
+    FileSystem fileSystem, {
+    ProcessRunner processRunner = const ProcessRunner(),
+    GitDir? gitDir,
+  }) : super(packagesDir, fileSystem,
+            processRunner: processRunner, gitDir: gitDir);
+
+  // Section order for plugins. Because the 'flutter' section is critical
+  // information for plugins, and usually small, it goes near the top unlike in
+  // a normal app or package.
+  static const List<String> _majorPluginSections = <String>[
+    'environment:',
+    'flutter:',
+    'dependencies:',
+    'dev_dependencies:',
+  ];
+
+  static const List<String> _majorPackageSections = <String>[
+    'environment:',
+    'dependencies:',
+    'dev_dependencies:',
+    'flutter:',
+  ];
+
+  static const String _expectedIssueLinkFormat =
+      'https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A';
+
+  @override
+  final String name = 'pubspec-check';
+
+  @override
+  final String description =
+      'Checks that pubspecs follow repository conventions.';
+
+  @override
+  Future<void> run() async {
+    final List<String> failingPackages = <String>[];
+    await for (final Directory package in getPackages()) {
+      final String relativePackagePath =
+          p.relative(package.path, from: packagesDir.path);
+      print('Checking $relativePackagePath...');
+      final File pubspec = package.childFile('pubspec.yaml');
+      final bool passesCheck = !pubspec.existsSync() ||
+          await _checkPubspec(pubspec, packageName: package.basename);
+      if (!passesCheck) {
+        failingPackages.add(relativePackagePath);
+      }
+    }
+
+    if (failingPackages.isNotEmpty) {
+      print('The following packages have pubspec issues:');
+      for (final String package in failingPackages) {
+        print('  $package');
+      }
+      throw ToolExit(1);
+    }
+
+    print('\nNo pubspec issues found!');
+  }
+
+  Future<bool> _checkPubspec(
+    File pubspecFile, {
+    required String packageName,
+  }) async {
+    const String indentation = '  ';
+    final String contents = pubspecFile.readAsStringSync();
+    final Pubspec? pubspec = _tryParsePubspec(contents);
+    if (pubspec == null) {
+      return false;
+    }
+
+    final List<String> pubspecLines = contents.split('\n');
+    final List<String> sectionOrder = pubspecLines.contains('  plugin:')
+        ? _majorPluginSections
+        : _majorPackageSections;
+    bool passing = _checkSectionOrder(pubspecLines, sectionOrder);
+    if (!passing) {
+      print('${indentation}Major sections should follow standard '
+          'repository ordering:');
+      final String listIndentation = indentation * 2;
+      print('$listIndentation${sectionOrder.join('\n$listIndentation')}');
+    }
+
+    if (pubspec.publishTo != 'none') {
+      final List<String> repositoryErrors =
+          _checkForRepositoryLinkErrors(pubspec, packageName: packageName);
+      if (repositoryErrors.isNotEmpty) {
+        for (final String error in repositoryErrors) {
+          print('$indentation$error');
+        }
+        passing = false;
+      }
+
+      if (!_checkIssueLink(pubspec)) {
+        print(
+            '${indentation}A package should have an "issue_tracker" link to a '
+            'search for open flutter/flutter bugs with the relevant label:\n'
+            '${indentation * 2}$_expectedIssueLinkFormat<package label>');
+        passing = false;
+      }
+    }
+
+    return passing;
+  }
+
+  Pubspec? _tryParsePubspec(String pubspecContents) {
+    try {
+      return Pubspec.parse(pubspecContents);
+    } on Exception catch (exception) {
+      print('  Cannot parse pubspec.yaml: $exception');
+    }
+    return null;
+  }
+
+  bool _checkSectionOrder(
+      List<String> pubspecLines, List<String> sectionOrder) {
+    int previousSectionIndex = 0;
+    for (final String line in pubspecLines) {
+      final int index = sectionOrder.indexOf(line);
+      if (index == -1) {
+        continue;
+      }
+      if (index < previousSectionIndex) {
+        return false;
+      }
+      previousSectionIndex = index;
+    }
+    return true;
+  }
+
+  List<String> _checkForRepositoryLinkErrors(
+    Pubspec pubspec, {
+    required String packageName,
+  }) {
+    final List<String> errorMessages = <String>[];
+    if (pubspec.repository == null) {
+      errorMessages.add('Missing "repository"');
+    } else if (!pubspec.repository!.path.endsWith(packageName)) {
+      errorMessages
+          .add('The "repository" link should end with the package name.');
+    }
+
+    if (pubspec.homepage != null) {
+      errorMessages
+          .add('Found a "homepage" entry; only "repository" should be used.');
+    }
+
+    return errorMessages;
+  }
+
+  bool _checkIssueLink(Pubspec pubspec) {
+    return pubspec.issueTracker
+            ?.toString()
+            .startsWith(_expectedIssueLinkFormat) ==
+        true;
+  }
+}