diff --git a/script/tool/lib/src/analyze_command.dart b/script/tool/lib/src/analyze_command.dart
index 076c8f6..003f0bc 100644
--- a/script/tool/lib/src/analyze_command.dart
+++ b/script/tool/lib/src/analyze_command.dart
@@ -7,7 +7,9 @@
 import 'package:file/file.dart';
 import 'package:path/path.dart' as p;
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/plugin_command.dart';
+import 'common/process_runner.dart';
 
 /// A command to run Dart analysis on packages.
 class AnalyzeCommand extends PluginCommand {
diff --git a/script/tool/lib/src/build_examples_command.dart b/script/tool/lib/src/build_examples_command.dart
index 9590aec..61d291d 100644
--- a/script/tool/lib/src/build_examples_command.dart
+++ b/script/tool/lib/src/build_examples_command.dart
@@ -9,7 +9,10 @@
 import 'package:path/path.dart' as p;
 import 'package:platform/platform.dart';
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/plugin_command.dart';
+import 'common/plugin_utils.dart';
+import 'common/process_runner.dart';
 
 /// Key for IPA.
 const String kIpa = 'ipa';
diff --git a/script/tool/lib/src/common.dart b/script/tool/lib/src/common.dart
deleted file mode 100644
index 5d653ad..0000000
--- a/script/tool/lib/src/common.dart
+++ /dev/null
@@ -1,781 +0,0 @@
-// 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 'dart:convert';
-import 'dart:io' as io;
-import 'dart:math';
-
-import 'package:args/command_runner.dart';
-import 'package:colorize/colorize.dart';
-import 'package:file/file.dart';
-import 'package:git/git.dart';
-import 'package:http/http.dart' as http;
-import 'package:path/path.dart' as p;
-import 'package:pub_semver/pub_semver.dart';
-import 'package:yaml/yaml.dart';
-
-/// The signature for a print handler for commands that allow overriding the
-/// print destination.
-typedef Print = void Function(Object? object);
-
-/// Key for windows platform.
-const String kPlatformFlagWindows = 'windows';
-
-/// Key for macos platform.
-const String kPlatformFlagMacos = 'macos';
-
-/// Key for linux platform.
-const String kPlatformFlagLinux = 'linux';
-
-/// Key for IPA (iOS) platform.
-const String kPlatformFlagIos = 'ios';
-
-/// Key for APK (Android) platform.
-const String kPlatformFlagAndroid = 'android';
-
-/// Key for Web platform.
-const String kPlatformFlagWeb = 'web';
-
-/// Key for enable experiment.
-const String kEnableExperiment = 'enable-experiment';
-
-/// Returns whether the given directory contains a Flutter package.
-bool isFlutterPackage(FileSystemEntity entity) {
-  if (entity is! Directory) {
-    return false;
-  }
-
-  try {
-    final File pubspecFile = entity.childFile('pubspec.yaml');
-    final YamlMap pubspecYaml =
-        loadYaml(pubspecFile.readAsStringSync()) as YamlMap;
-    final YamlMap? dependencies = pubspecYaml['dependencies'] as YamlMap?;
-    if (dependencies == null) {
-      return false;
-    }
-    return dependencies.containsKey('flutter');
-  } on FileSystemException {
-    return false;
-  } on YamlException {
-    return false;
-  }
-}
-
-/// Possible plugin support options for a platform.
-enum PlatformSupport {
-  /// The platform has an implementation in the package.
-  inline,
-
-  /// The platform has an endorsed federated implementation in another package.
-  federated,
-}
-
-/// Returns whether the given directory contains a Flutter [platform] plugin.
-///
-/// It checks this by looking for the following pattern in the pubspec:
-///
-///     flutter:
-///       plugin:
-///         platforms:
-///           [platform]:
-///
-/// If [requiredMode] is provided, the plugin must have the given type of
-/// implementation in order to return true.
-bool pluginSupportsPlatform(String platform, FileSystemEntity entity,
-    {PlatformSupport? requiredMode}) {
-  assert(platform == kPlatformFlagIos ||
-      platform == kPlatformFlagAndroid ||
-      platform == kPlatformFlagWeb ||
-      platform == kPlatformFlagMacos ||
-      platform == kPlatformFlagWindows ||
-      platform == kPlatformFlagLinux);
-  if (entity is! Directory) {
-    return false;
-  }
-
-  try {
-    final File pubspecFile = entity.childFile('pubspec.yaml');
-    final YamlMap pubspecYaml =
-        loadYaml(pubspecFile.readAsStringSync()) as YamlMap;
-    final YamlMap? flutterSection = pubspecYaml['flutter'] as YamlMap?;
-    if (flutterSection == null) {
-      return false;
-    }
-    final YamlMap? pluginSection = flutterSection['plugin'] as YamlMap?;
-    if (pluginSection == null) {
-      return false;
-    }
-    final YamlMap? platforms = pluginSection['platforms'] as YamlMap?;
-    if (platforms == null) {
-      // Legacy plugin specs are assumed to support iOS and Android. They are
-      // never federated.
-      if (requiredMode == PlatformSupport.federated) {
-        return false;
-      }
-      if (!pluginSection.containsKey('platforms')) {
-        return platform == kPlatformFlagIos || platform == kPlatformFlagAndroid;
-      }
-      return false;
-    }
-    final YamlMap? platformEntry = platforms[platform] as YamlMap?;
-    if (platformEntry == null) {
-      return false;
-    }
-    // If the platform entry is present, then it supports the platform. Check
-    // for required mode if specified.
-    final bool federated = platformEntry.containsKey('default_package');
-    return requiredMode == null ||
-        federated == (requiredMode == PlatformSupport.federated);
-  } on FileSystemException {
-    return false;
-  } on YamlException {
-    return false;
-  }
-}
-
-/// Returns whether the given directory contains a Flutter Android plugin.
-bool isAndroidPlugin(FileSystemEntity entity) {
-  return pluginSupportsPlatform(kPlatformFlagAndroid, entity);
-}
-
-/// Returns whether the given directory contains a Flutter iOS plugin.
-bool isIosPlugin(FileSystemEntity entity) {
-  return pluginSupportsPlatform(kPlatformFlagIos, entity);
-}
-
-/// Returns whether the given directory contains a Flutter web plugin.
-bool isWebPlugin(FileSystemEntity entity) {
-  return pluginSupportsPlatform(kPlatformFlagWeb, entity);
-}
-
-/// Returns whether the given directory contains a Flutter Windows plugin.
-bool isWindowsPlugin(FileSystemEntity entity) {
-  return pluginSupportsPlatform(kPlatformFlagWindows, entity);
-}
-
-/// Returns whether the given directory contains a Flutter macOS plugin.
-bool isMacOsPlugin(FileSystemEntity entity) {
-  return pluginSupportsPlatform(kPlatformFlagMacos, entity);
-}
-
-/// Returns whether the given directory contains a Flutter linux plugin.
-bool isLinuxPlugin(FileSystemEntity entity) {
-  return pluginSupportsPlatform(kPlatformFlagLinux, entity);
-}
-
-/// Prints `errorMessage` in red.
-void printError(String errorMessage) {
-  final Colorize redError = Colorize(errorMessage)..red();
-  print(redError);
-}
-
-/// Error thrown when a command needs to exit with a non-zero exit code.
-class ToolExit extends Error {
-  /// Creates a tool exit with the given [exitCode].
-  ToolExit(this.exitCode);
-
-  /// The code that the process should exit with.
-  final int exitCode;
-}
-
-/// Interface definition for all commands in this tool.
-abstract class PluginCommand extends Command<void> {
-  /// Creates a command to operate on [packagesDir] with the given environment.
-  PluginCommand(
-    this.packagesDir, {
-    this.processRunner = const ProcessRunner(),
-    this.gitDir,
-  }) {
-    argParser.addMultiOption(
-      _pluginsArg,
-      splitCommas: true,
-      help:
-          'Specifies which plugins the command should run on (before sharding).',
-      valueHelp: 'plugin1,plugin2,...',
-    );
-    argParser.addOption(
-      _shardIndexArg,
-      help: 'Specifies the zero-based index of the shard to '
-          'which the command applies.',
-      valueHelp: 'i',
-      defaultsTo: '0',
-    );
-    argParser.addOption(
-      _shardCountArg,
-      help: 'Specifies the number of shards into which plugins are divided.',
-      valueHelp: 'n',
-      defaultsTo: '1',
-    );
-    argParser.addMultiOption(
-      _excludeArg,
-      abbr: 'e',
-      help: 'Exclude packages from this command.',
-      defaultsTo: <String>[],
-    );
-    argParser.addFlag(_runOnChangedPackagesArg,
-        help: 'Run the command on changed packages/plugins.\n'
-            'If the $_pluginsArg is specified, this flag is ignored.\n'
-            'If no packages have changed, or if there have been changes that may\n'
-            'affect all packages, the command runs on all packages.\n'
-            'The packages excluded with $_excludeArg is also excluded even if changed.\n'
-            'See $_kBaseSha if a custom base is needed to determine the diff.');
-    argParser.addOption(_kBaseSha,
-        help: 'The base sha used to determine git diff. \n'
-            'This is useful when $_runOnChangedPackagesArg is specified.\n'
-            'If not specified, merge-base is used as base sha.');
-  }
-
-  static const String _pluginsArg = 'plugins';
-  static const String _shardIndexArg = 'shardIndex';
-  static const String _shardCountArg = 'shardCount';
-  static const String _excludeArg = 'exclude';
-  static const String _runOnChangedPackagesArg = 'run-on-changed-packages';
-  static const String _kBaseSha = 'base-sha';
-
-  /// The directory containing the plugin packages.
-  final Directory packagesDir;
-
-  /// The process runner.
-  ///
-  /// This can be overridden for testing.
-  final ProcessRunner processRunner;
-
-  /// The git directory to use. By default it uses the parent directory.
-  ///
-  /// This can be mocked for testing.
-  final GitDir? gitDir;
-
-  int? _shardIndex;
-  int? _shardCount;
-
-  /// The shard of the overall command execution that this instance should run.
-  int get shardIndex {
-    if (_shardIndex == null) {
-      _checkSharding();
-    }
-    return _shardIndex!;
-  }
-
-  /// The number of shards this command is divided into.
-  int get shardCount {
-    if (_shardCount == null) {
-      _checkSharding();
-    }
-    return _shardCount!;
-  }
-
-  /// Convenience accessor for boolean arguments.
-  bool getBoolArg(String key) {
-    return (argResults![key] as bool?) ?? false;
-  }
-
-  /// Convenience accessor for String arguments.
-  String getStringArg(String key) {
-    return (argResults![key] as String?) ?? '';
-  }
-
-  /// Convenience accessor for List<String> arguments.
-  List<String> getStringListArg(String key) {
-    return (argResults![key] as List<String>?) ?? <String>[];
-  }
-
-  void _checkSharding() {
-    final int? shardIndex = int.tryParse(getStringArg(_shardIndexArg));
-    final int? shardCount = int.tryParse(getStringArg(_shardCountArg));
-    if (shardIndex == null) {
-      usageException('$_shardIndexArg must be an integer');
-    }
-    if (shardCount == null) {
-      usageException('$_shardCountArg must be an integer');
-    }
-    if (shardCount < 1) {
-      usageException('$_shardCountArg must be positive');
-    }
-    if (shardIndex < 0 || shardCount <= shardIndex) {
-      usageException(
-          '$_shardIndexArg must be in the half-open range [0..$shardCount[');
-    }
-    _shardIndex = shardIndex;
-    _shardCount = shardCount;
-  }
-
-  /// Returns the root Dart package folders of the plugins involved in this
-  /// command execution.
-  Stream<Directory> getPlugins() async* {
-    // To avoid assuming consistency of `Directory.list` across command
-    // invocations, we collect and sort the plugin folders before sharding.
-    // This is considered an implementation detail which is why the API still
-    // uses streams.
-    final List<Directory> allPlugins = await _getAllPlugins().toList();
-    allPlugins.sort((Directory d1, Directory d2) => d1.path.compareTo(d2.path));
-    // Sharding 10 elements into 3 shards should yield shard sizes 4, 4, 2.
-    // Sharding  9 elements into 3 shards should yield shard sizes 3, 3, 3.
-    // Sharding  2 elements into 3 shards should yield shard sizes 1, 1, 0.
-    final int shardSize = allPlugins.length ~/ shardCount +
-        (allPlugins.length % shardCount == 0 ? 0 : 1);
-    final int start = min(shardIndex * shardSize, allPlugins.length);
-    final int end = min(start + shardSize, allPlugins.length);
-
-    for (final Directory plugin in allPlugins.sublist(start, end)) {
-      yield plugin;
-    }
-  }
-
-  /// Returns the root Dart package folders of the plugins involved in this
-  /// command execution, assuming there is only one shard.
-  ///
-  /// Plugin packages can exist in the following places relative to the packages
-  /// directory:
-  ///
-  /// 1. As a Dart package in a directory which is a direct child of the
-  ///    packages directory. This is a plugin where all of the implementations
-  ///    exist in a single Dart package.
-  /// 2. Several plugin packages may live in a directory which is a direct
-  ///    child of the packages directory. This directory groups several Dart
-  ///    packages which implement a single plugin. This directory contains a
-  ///    "client library" package, which declares the API for the plugin, as
-  ///    well as one or more platform-specific implementations.
-  /// 3./4. Either of the above, but in a third_party/packages/ directory that
-  ///    is a sibling of the packages directory. This is used for a small number
-  ///    of packages in the flutter/packages repository.
-  Stream<Directory> _getAllPlugins() async* {
-    Set<String> plugins = Set<String>.from(getStringListArg(_pluginsArg));
-    final Set<String> excludedPlugins =
-        Set<String>.from(getStringListArg(_excludeArg));
-    final bool runOnChangedPackages = getBoolArg(_runOnChangedPackagesArg);
-    if (plugins.isEmpty &&
-        runOnChangedPackages &&
-        !(await _changesRequireFullTest())) {
-      plugins = await _getChangedPackages();
-    }
-
-    final Directory thirdPartyPackagesDirectory = packagesDir.parent
-        .childDirectory('third_party')
-        .childDirectory('packages');
-
-    for (final Directory dir in <Directory>[
-      packagesDir,
-      if (thirdPartyPackagesDirectory.existsSync()) thirdPartyPackagesDirectory,
-    ]) {
-      await for (final FileSystemEntity entity
-          in dir.list(followLinks: false)) {
-        // A top-level Dart package is a plugin package.
-        if (_isDartPackage(entity)) {
-          if (!excludedPlugins.contains(entity.basename) &&
-              (plugins.isEmpty || plugins.contains(p.basename(entity.path)))) {
-            yield entity as Directory;
-          }
-        } else if (entity is Directory) {
-          // Look for Dart packages under this top-level directory.
-          await for (final FileSystemEntity subdir
-              in entity.list(followLinks: false)) {
-            if (_isDartPackage(subdir)) {
-              // If --plugin=my_plugin is passed, then match all federated
-              // plugins under 'my_plugin'. Also match if the exact plugin is
-              // passed.
-              final String relativePath =
-                  p.relative(subdir.path, from: dir.path);
-              final String packageName = p.basename(subdir.path);
-              final String basenamePath = p.basename(entity.path);
-              if (!excludedPlugins.contains(basenamePath) &&
-                  !excludedPlugins.contains(packageName) &&
-                  !excludedPlugins.contains(relativePath) &&
-                  (plugins.isEmpty ||
-                      plugins.contains(relativePath) ||
-                      plugins.contains(basenamePath))) {
-                yield subdir as Directory;
-              }
-            }
-          }
-        }
-      }
-    }
-  }
-
-  /// Returns the example Dart package folders of the plugins involved in this
-  /// command execution.
-  Stream<Directory> getExamples() =>
-      getPlugins().expand<Directory>(getExamplesForPlugin);
-
-  /// Returns all Dart package folders (typically, plugin + example) of the
-  /// plugins involved in this command execution.
-  Stream<Directory> getPackages() async* {
-    await for (final Directory plugin in getPlugins()) {
-      yield plugin;
-      yield* plugin
-          .list(recursive: true, followLinks: false)
-          .where(_isDartPackage)
-          .cast<Directory>();
-    }
-  }
-
-  /// Returns the files contained, recursively, within the plugins
-  /// involved in this command execution.
-  Stream<File> getFiles() {
-    return getPlugins().asyncExpand<File>((Directory folder) => folder
-        .list(recursive: true, followLinks: false)
-        .where((FileSystemEntity entity) => entity is File)
-        .cast<File>());
-  }
-
-  /// Returns whether the specified entity is a directory containing a
-  /// `pubspec.yaml` file.
-  bool _isDartPackage(FileSystemEntity entity) {
-    return entity is Directory && entity.childFile('pubspec.yaml').existsSync();
-  }
-
-  /// Returns the example Dart packages contained in the specified plugin, or
-  /// an empty List, if the plugin has no examples.
-  Iterable<Directory> getExamplesForPlugin(Directory plugin) {
-    final Directory exampleFolder = plugin.childDirectory('example');
-    if (!exampleFolder.existsSync()) {
-      return <Directory>[];
-    }
-    if (isFlutterPackage(exampleFolder)) {
-      return <Directory>[exampleFolder];
-    }
-    // Only look at the subdirectories of the example directory if the example
-    // directory itself is not a Dart package, and only look one level below the
-    // example directory for other dart packages.
-    return exampleFolder
-        .listSync()
-        .where((FileSystemEntity entity) => isFlutterPackage(entity))
-        .cast<Directory>();
-  }
-
-  /// Retrieve an instance of [GitVersionFinder] based on `_kBaseSha` and [gitDir].
-  ///
-  /// Throws tool exit if [gitDir] nor root directory is a git directory.
-  Future<GitVersionFinder> retrieveVersionFinder() async {
-    final String rootDir = packagesDir.parent.absolute.path;
-    final String baseSha = getStringArg(_kBaseSha);
-
-    GitDir? baseGitDir = gitDir;
-    if (baseGitDir == null) {
-      if (!await GitDir.isGitDir(rootDir)) {
-        printError(
-          '$rootDir is not a valid Git repository.',
-        );
-        throw ToolExit(2);
-      }
-      baseGitDir = await GitDir.fromExisting(rootDir);
-    }
-
-    final GitVersionFinder gitVersionFinder =
-        GitVersionFinder(baseGitDir, baseSha);
-    return gitVersionFinder;
-  }
-
-  // Returns packages that have been changed relative to the git base.
-  Future<Set<String>> _getChangedPackages() async {
-    final GitVersionFinder gitVersionFinder = await retrieveVersionFinder();
-
-    final List<String> allChangedFiles =
-        await gitVersionFinder.getChangedFiles();
-    final Set<String> packages = <String>{};
-    for (final String path in allChangedFiles) {
-      final List<String> pathComponents = path.split('/');
-      final int packagesIndex =
-          pathComponents.indexWhere((String element) => element == 'packages');
-      if (packagesIndex != -1) {
-        packages.add(pathComponents[packagesIndex + 1]);
-      }
-    }
-    if (packages.isEmpty) {
-      print('No changed packages.');
-    } else {
-      final String changedPackages = packages.join(',');
-      print('Changed packages: $changedPackages');
-    }
-    return packages;
-  }
-
-  // Returns true if one or more files changed that have the potential to affect
-  // any plugin (e.g., CI script changes).
-  Future<bool> _changesRequireFullTest() async {
-    final GitVersionFinder gitVersionFinder = await retrieveVersionFinder();
-
-    const List<String> specialFiles = <String>[
-      '.ci.yaml', // LUCI config.
-      '.cirrus.yml', // Cirrus config.
-      '.clang-format', // ObjC and C/C++ formatting options.
-      'analysis_options.yaml', // Dart analysis settings.
-    ];
-    const List<String> specialDirectories = <String>[
-      '.ci/', // Support files for CI.
-      'script/', // This tool, and its wrapper scripts.
-    ];
-    // Directory entries must end with / to avoid over-matching, since the
-    // check below is done via string prefixing.
-    assert(specialDirectories.every((String dir) => dir.endsWith('/')));
-
-    final List<String> allChangedFiles =
-        await gitVersionFinder.getChangedFiles();
-    return allChangedFiles.any((String path) =>
-        specialFiles.contains(path) ||
-        specialDirectories.any((String dir) => path.startsWith(dir)));
-  }
-}
-
-/// A class used to run processes.
-///
-/// We use this instead of directly running the process so it can be overridden
-/// in tests.
-class ProcessRunner {
-  /// Creates a new process runner.
-  const ProcessRunner();
-
-  /// Run the [executable] with [args] and stream output to stderr and stdout.
-  ///
-  /// The current working directory of [executable] can be overridden by
-  /// passing [workingDir].
-  ///
-  /// If [exitOnError] is set to `true`, then this will throw an error if
-  /// the [executable] terminates with a non-zero exit code.
-  ///
-  /// Returns the exit code of the [executable].
-  Future<int> runAndStream(
-    String executable,
-    List<String> args, {
-    Directory? workingDir,
-    bool exitOnError = false,
-  }) async {
-    print(
-        'Running command: "$executable ${args.join(' ')}" in ${workingDir?.path ?? io.Directory.current.path}');
-    final io.Process process = await io.Process.start(executable, args,
-        workingDirectory: workingDir?.path);
-    await io.stdout.addStream(process.stdout);
-    await io.stderr.addStream(process.stderr);
-    if (exitOnError && await process.exitCode != 0) {
-      final String error =
-          _getErrorString(executable, args, workingDir: workingDir);
-      print('$error See above for details.');
-      throw ToolExit(await process.exitCode);
-    }
-    return process.exitCode;
-  }
-
-  /// Run the [executable] with [args].
-  ///
-  /// The current working directory of [executable] can be overridden by
-  /// passing [workingDir].
-  ///
-  /// If [exitOnError] is set to `true`, then this will throw an error if
-  /// the [executable] terminates with a non-zero exit code.
-  /// Defaults to `false`.
-  ///
-  /// If [logOnError] is set to `true`, it will print a formatted message about the error.
-  /// Defaults to `false`
-  ///
-  /// Returns the [io.ProcessResult] of the [executable].
-  Future<io.ProcessResult> run(String executable, List<String> args,
-      {Directory? workingDir,
-      bool exitOnError = false,
-      bool logOnError = false,
-      Encoding stdoutEncoding = io.systemEncoding,
-      Encoding stderrEncoding = io.systemEncoding}) async {
-    final io.ProcessResult result = await io.Process.run(executable, args,
-        workingDirectory: workingDir?.path,
-        stdoutEncoding: stdoutEncoding,
-        stderrEncoding: stderrEncoding);
-    if (result.exitCode != 0) {
-      if (logOnError) {
-        final String error =
-            _getErrorString(executable, args, workingDir: workingDir);
-        print('$error Stderr:\n${result.stdout}');
-      }
-      if (exitOnError) {
-        throw ToolExit(result.exitCode);
-      }
-    }
-    return result;
-  }
-
-  /// Starts the [executable] with [args].
-  ///
-  /// The current working directory of [executable] can be overridden by
-  /// passing [workingDir].
-  ///
-  /// Returns the started [io.Process].
-  Future<io.Process> start(String executable, List<String> args,
-      {Directory? workingDirectory}) async {
-    final io.Process process = await io.Process.start(executable, args,
-        workingDirectory: workingDirectory?.path);
-    return process;
-  }
-
-  String _getErrorString(String executable, List<String> args,
-      {Directory? workingDir}) {
-    final String workdir = workingDir == null ? '' : ' in ${workingDir.path}';
-    return 'ERROR: Unable to execute "$executable ${args.join(' ')}"$workdir.';
-  }
-}
-
-/// Finding version of [package] that is published on pub.
-class PubVersionFinder {
-  /// Constructor.
-  ///
-  /// Note: you should manually close the [httpClient] when done using the finder.
-  PubVersionFinder({this.pubHost = defaultPubHost, required this.httpClient});
-
-  /// The default pub host to use.
-  static const String defaultPubHost = 'https://pub.dev';
-
-  /// The pub host url, defaults to `https://pub.dev`.
-  final String pubHost;
-
-  /// The http client.
-  ///
-  /// You should manually close this client when done using this finder.
-  final http.Client httpClient;
-
-  /// Get the package version on pub.
-  Future<PubVersionFinderResponse> getPackageVersion(
-      {required String package}) async {
-    assert(package.isNotEmpty);
-    final Uri pubHostUri = Uri.parse(pubHost);
-    final Uri url = pubHostUri.replace(path: '/packages/$package.json');
-    final http.Response response = await httpClient.get(url);
-
-    if (response.statusCode == 404) {
-      return PubVersionFinderResponse(
-          versions: <Version>[],
-          result: PubVersionFinderResult.noPackageFound,
-          httpResponse: response);
-    } else if (response.statusCode != 200) {
-      return PubVersionFinderResponse(
-          versions: <Version>[],
-          result: PubVersionFinderResult.fail,
-          httpResponse: response);
-    }
-    final List<Version> versions =
-        (json.decode(response.body)['versions'] as List<dynamic>)
-            .map<Version>((final dynamic versionString) =>
-                Version.parse(versionString as String))
-            .toList();
-
-    return PubVersionFinderResponse(
-        versions: versions,
-        result: PubVersionFinderResult.success,
-        httpResponse: response);
-  }
-}
-
-/// Represents a response for [PubVersionFinder].
-class PubVersionFinderResponse {
-  /// Constructor.
-  PubVersionFinderResponse(
-      {required this.versions,
-      required this.result,
-      required this.httpResponse}) {
-    if (versions.isNotEmpty) {
-      versions.sort((Version a, Version b) {
-        // TODO(cyanglaz): Think about how to handle pre-release version with [Version.prioritize].
-        // https://github.com/flutter/flutter/issues/82222
-        return b.compareTo(a);
-      });
-    }
-  }
-
-  /// The versions found in [PubVersionFinder].
-  ///
-  /// This is sorted by largest to smallest, so the first element in the list is the largest version.
-  /// Might be `null` if the [result] is not [PubVersionFinderResult.success].
-  final List<Version> versions;
-
-  /// The result of the version finder.
-  final PubVersionFinderResult result;
-
-  /// The response object of the http request.
-  final http.Response httpResponse;
-}
-
-/// An enum representing the result of [PubVersionFinder].
-enum PubVersionFinderResult {
-  /// The version finder successfully found a version.
-  success,
-
-  /// The version finder failed to find a valid version.
-  ///
-  /// This might due to http connection errors or user errors.
-  fail,
-
-  /// The version finder failed to locate the package.
-  ///
-  /// This indicates the package is new.
-  noPackageFound,
-}
-
-/// Finding diffs based on `baseGitDir` and `baseSha`.
-class GitVersionFinder {
-  /// Constructor
-  GitVersionFinder(this.baseGitDir, this.baseSha);
-
-  /// The top level directory of the git repo.
-  ///
-  /// That is where the .git/ folder exists.
-  final GitDir baseGitDir;
-
-  /// The base sha used to get diff.
-  final String? baseSha;
-
-  static bool _isPubspec(String file) {
-    return file.trim().endsWith('pubspec.yaml');
-  }
-
-  /// Get a list of all the pubspec.yaml file that is changed.
-  Future<List<String>> getChangedPubSpecs() async {
-    return (await getChangedFiles()).where(_isPubspec).toList();
-  }
-
-  /// Get a list of all the changed files.
-  Future<List<String>> getChangedFiles() async {
-    final String baseSha = await _getBaseSha();
-    final io.ProcessResult changedFilesCommand = await baseGitDir
-        .runCommand(<String>['diff', '--name-only', baseSha, 'HEAD']);
-    print('Determine diff with base sha: $baseSha');
-    final String changedFilesStdout = changedFilesCommand.stdout.toString();
-    if (changedFilesStdout.isEmpty) {
-      return <String>[];
-    }
-    final List<String> changedFiles = changedFilesStdout.split('\n')
-      ..removeWhere((String element) => element.isEmpty);
-    return changedFiles.toList();
-  }
-
-  /// Get the package version specified in the pubspec file in `pubspecPath` and
-  /// at the revision of `gitRef` (defaulting to the base if not provided).
-  Future<Version?> getPackageVersion(String pubspecPath,
-      {String? gitRef}) async {
-    final String ref = gitRef ?? (await _getBaseSha());
-
-    io.ProcessResult gitShow;
-    try {
-      gitShow =
-          await baseGitDir.runCommand(<String>['show', '$ref:$pubspecPath']);
-    } on io.ProcessException {
-      return null;
-    }
-    final String fileContent = gitShow.stdout as String;
-    final String? versionString = loadYaml(fileContent)['version'] as String?;
-    return versionString == null ? null : Version.parse(versionString);
-  }
-
-  Future<String> _getBaseSha() async {
-    if (baseSha != null && baseSha!.isNotEmpty) {
-      return baseSha!;
-    }
-
-    io.ProcessResult baseShaFromMergeBase = await baseGitDir.runCommand(
-        <String>['merge-base', '--fork-point', 'FETCH_HEAD', 'HEAD'],
-        throwOnError: false);
-    if (baseShaFromMergeBase.stderr != null ||
-        baseShaFromMergeBase.stdout == null) {
-      baseShaFromMergeBase = await baseGitDir
-          .runCommand(<String>['merge-base', 'FETCH_HEAD', 'HEAD']);
-    }
-    return (baseShaFromMergeBase.stdout as String).trim();
-  }
-}
diff --git a/script/tool/lib/src/common/core.dart b/script/tool/lib/src/common/core.dart
new file mode 100644
index 0000000..4788b9f
--- /dev/null
+++ b/script/tool/lib/src/common/core.dart
@@ -0,0 +1,69 @@
+// 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 'package:colorize/colorize.dart';
+import 'package:file/file.dart';
+import 'package:yaml/yaml.dart';
+
+/// The signature for a print handler for commands that allow overriding the
+/// print destination.
+typedef Print = void Function(Object? object);
+
+/// Key for windows platform.
+const String kPlatformFlagWindows = 'windows';
+
+/// Key for macos platform.
+const String kPlatformFlagMacos = 'macos';
+
+/// Key for linux platform.
+const String kPlatformFlagLinux = 'linux';
+
+/// Key for IPA (iOS) platform.
+const String kPlatformFlagIos = 'ios';
+
+/// Key for APK (Android) platform.
+const String kPlatformFlagAndroid = 'android';
+
+/// Key for Web platform.
+const String kPlatformFlagWeb = 'web';
+
+/// Key for enable experiment.
+const String kEnableExperiment = 'enable-experiment';
+
+/// Returns whether the given directory contains a Flutter package.
+bool isFlutterPackage(FileSystemEntity entity) {
+  if (entity is! Directory) {
+    return false;
+  }
+
+  try {
+    final File pubspecFile = entity.childFile('pubspec.yaml');
+    final YamlMap pubspecYaml =
+        loadYaml(pubspecFile.readAsStringSync()) as YamlMap;
+    final YamlMap? dependencies = pubspecYaml['dependencies'] as YamlMap?;
+    if (dependencies == null) {
+      return false;
+    }
+    return dependencies.containsKey('flutter');
+  } on FileSystemException {
+    return false;
+  } on YamlException {
+    return false;
+  }
+}
+
+/// Prints `errorMessage` in red.
+void printError(String errorMessage) {
+  final Colorize redError = Colorize(errorMessage)..red();
+  print(redError);
+}
+
+/// Error thrown when a command needs to exit with a non-zero exit code.
+class ToolExit extends Error {
+  /// Creates a tool exit with the given [exitCode].
+  ToolExit(this.exitCode);
+
+  /// The code that the process should exit with.
+  final int exitCode;
+}
diff --git a/script/tool/lib/src/common/git_version_finder.dart b/script/tool/lib/src/common/git_version_finder.dart
new file mode 100644
index 0000000..2c9519e
--- /dev/null
+++ b/script/tool/lib/src/common/git_version_finder.dart
@@ -0,0 +1,81 @@
+// 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:io' as io;
+
+import 'package:git/git.dart';
+import 'package:pub_semver/pub_semver.dart';
+import 'package:yaml/yaml.dart';
+
+/// Finding diffs based on `baseGitDir` and `baseSha`.
+class GitVersionFinder {
+  /// Constructor
+  GitVersionFinder(this.baseGitDir, this.baseSha);
+
+  /// The top level directory of the git repo.
+  ///
+  /// That is where the .git/ folder exists.
+  final GitDir baseGitDir;
+
+  /// The base sha used to get diff.
+  final String? baseSha;
+
+  static bool _isPubspec(String file) {
+    return file.trim().endsWith('pubspec.yaml');
+  }
+
+  /// Get a list of all the pubspec.yaml file that is changed.
+  Future<List<String>> getChangedPubSpecs() async {
+    return (await getChangedFiles()).where(_isPubspec).toList();
+  }
+
+  /// Get a list of all the changed files.
+  Future<List<String>> getChangedFiles() async {
+    final String baseSha = await _getBaseSha();
+    final io.ProcessResult changedFilesCommand = await baseGitDir
+        .runCommand(<String>['diff', '--name-only', baseSha, 'HEAD']);
+    print('Determine diff with base sha: $baseSha');
+    final String changedFilesStdout = changedFilesCommand.stdout.toString();
+    if (changedFilesStdout.isEmpty) {
+      return <String>[];
+    }
+    final List<String> changedFiles = changedFilesStdout.split('\n')
+      ..removeWhere((String element) => element.isEmpty);
+    return changedFiles.toList();
+  }
+
+  /// Get the package version specified in the pubspec file in `pubspecPath` and
+  /// at the revision of `gitRef` (defaulting to the base if not provided).
+  Future<Version?> getPackageVersion(String pubspecPath,
+      {String? gitRef}) async {
+    final String ref = gitRef ?? (await _getBaseSha());
+
+    io.ProcessResult gitShow;
+    try {
+      gitShow =
+          await baseGitDir.runCommand(<String>['show', '$ref:$pubspecPath']);
+    } on io.ProcessException {
+      return null;
+    }
+    final String fileContent = gitShow.stdout as String;
+    final String? versionString = loadYaml(fileContent)['version'] as String?;
+    return versionString == null ? null : Version.parse(versionString);
+  }
+
+  Future<String> _getBaseSha() async {
+    if (baseSha != null && baseSha!.isNotEmpty) {
+      return baseSha!;
+    }
+
+    io.ProcessResult baseShaFromMergeBase = await baseGitDir.runCommand(
+        <String>['merge-base', '--fork-point', 'FETCH_HEAD', 'HEAD'],
+        throwOnError: false);
+    if (baseShaFromMergeBase.stderr != null ||
+        baseShaFromMergeBase.stdout == null) {
+      baseShaFromMergeBase = await baseGitDir
+          .runCommand(<String>['merge-base', 'FETCH_HEAD', 'HEAD']);
+    }
+    return (baseShaFromMergeBase.stdout as String).trim();
+  }
+}
diff --git a/script/tool/lib/src/common/plugin_command.dart b/script/tool/lib/src/common/plugin_command.dart
new file mode 100644
index 0000000..1ab9d8d
--- /dev/null
+++ b/script/tool/lib/src/common/plugin_command.dart
@@ -0,0 +1,353 @@
+// 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:math';
+
+import 'package:args/command_runner.dart';
+import 'package:file/file.dart';
+import 'package:git/git.dart';
+import 'package:path/path.dart' as p;
+
+import 'core.dart';
+import 'git_version_finder.dart';
+import 'process_runner.dart';
+
+/// Interface definition for all commands in this tool.
+abstract class PluginCommand extends Command<void> {
+  /// Creates a command to operate on [packagesDir] with the given environment.
+  PluginCommand(
+    this.packagesDir, {
+    this.processRunner = const ProcessRunner(),
+    this.gitDir,
+  }) {
+    argParser.addMultiOption(
+      _pluginsArg,
+      splitCommas: true,
+      help:
+          'Specifies which plugins the command should run on (before sharding).',
+      valueHelp: 'plugin1,plugin2,...',
+    );
+    argParser.addOption(
+      _shardIndexArg,
+      help: 'Specifies the zero-based index of the shard to '
+          'which the command applies.',
+      valueHelp: 'i',
+      defaultsTo: '0',
+    );
+    argParser.addOption(
+      _shardCountArg,
+      help: 'Specifies the number of shards into which plugins are divided.',
+      valueHelp: 'n',
+      defaultsTo: '1',
+    );
+    argParser.addMultiOption(
+      _excludeArg,
+      abbr: 'e',
+      help: 'Exclude packages from this command.',
+      defaultsTo: <String>[],
+    );
+    argParser.addFlag(_runOnChangedPackagesArg,
+        help: 'Run the command on changed packages/plugins.\n'
+            'If the $_pluginsArg is specified, this flag is ignored.\n'
+            'If no packages have changed, or if there have been changes that may\n'
+            'affect all packages, the command runs on all packages.\n'
+            'The packages excluded with $_excludeArg is also excluded even if changed.\n'
+            'See $_kBaseSha if a custom base is needed to determine the diff.');
+    argParser.addOption(_kBaseSha,
+        help: 'The base sha used to determine git diff. \n'
+            'This is useful when $_runOnChangedPackagesArg is specified.\n'
+            'If not specified, merge-base is used as base sha.');
+  }
+
+  static const String _pluginsArg = 'plugins';
+  static const String _shardIndexArg = 'shardIndex';
+  static const String _shardCountArg = 'shardCount';
+  static const String _excludeArg = 'exclude';
+  static const String _runOnChangedPackagesArg = 'run-on-changed-packages';
+  static const String _kBaseSha = 'base-sha';
+
+  /// The directory containing the plugin packages.
+  final Directory packagesDir;
+
+  /// The process runner.
+  ///
+  /// This can be overridden for testing.
+  final ProcessRunner processRunner;
+
+  /// The git directory to use. By default it uses the parent directory.
+  ///
+  /// This can be mocked for testing.
+  final GitDir? gitDir;
+
+  int? _shardIndex;
+  int? _shardCount;
+
+  /// The shard of the overall command execution that this instance should run.
+  int get shardIndex {
+    if (_shardIndex == null) {
+      _checkSharding();
+    }
+    return _shardIndex!;
+  }
+
+  /// The number of shards this command is divided into.
+  int get shardCount {
+    if (_shardCount == null) {
+      _checkSharding();
+    }
+    return _shardCount!;
+  }
+
+  /// Convenience accessor for boolean arguments.
+  bool getBoolArg(String key) {
+    return (argResults![key] as bool?) ?? false;
+  }
+
+  /// Convenience accessor for String arguments.
+  String getStringArg(String key) {
+    return (argResults![key] as String?) ?? '';
+  }
+
+  /// Convenience accessor for List<String> arguments.
+  List<String> getStringListArg(String key) {
+    return (argResults![key] as List<String>?) ?? <String>[];
+  }
+
+  void _checkSharding() {
+    final int? shardIndex = int.tryParse(getStringArg(_shardIndexArg));
+    final int? shardCount = int.tryParse(getStringArg(_shardCountArg));
+    if (shardIndex == null) {
+      usageException('$_shardIndexArg must be an integer');
+    }
+    if (shardCount == null) {
+      usageException('$_shardCountArg must be an integer');
+    }
+    if (shardCount < 1) {
+      usageException('$_shardCountArg must be positive');
+    }
+    if (shardIndex < 0 || shardCount <= shardIndex) {
+      usageException(
+          '$_shardIndexArg must be in the half-open range [0..$shardCount[');
+    }
+    _shardIndex = shardIndex;
+    _shardCount = shardCount;
+  }
+
+  /// Returns the root Dart package folders of the plugins involved in this
+  /// command execution.
+  Stream<Directory> getPlugins() async* {
+    // To avoid assuming consistency of `Directory.list` across command
+    // invocations, we collect and sort the plugin folders before sharding.
+    // This is considered an implementation detail which is why the API still
+    // uses streams.
+    final List<Directory> allPlugins = await _getAllPlugins().toList();
+    allPlugins.sort((Directory d1, Directory d2) => d1.path.compareTo(d2.path));
+    // Sharding 10 elements into 3 shards should yield shard sizes 4, 4, 2.
+    // Sharding  9 elements into 3 shards should yield shard sizes 3, 3, 3.
+    // Sharding  2 elements into 3 shards should yield shard sizes 1, 1, 0.
+    final int shardSize = allPlugins.length ~/ shardCount +
+        (allPlugins.length % shardCount == 0 ? 0 : 1);
+    final int start = min(shardIndex * shardSize, allPlugins.length);
+    final int end = min(start + shardSize, allPlugins.length);
+
+    for (final Directory plugin in allPlugins.sublist(start, end)) {
+      yield plugin;
+    }
+  }
+
+  /// Returns the root Dart package folders of the plugins involved in this
+  /// command execution, assuming there is only one shard.
+  ///
+  /// Plugin packages can exist in the following places relative to the packages
+  /// directory:
+  ///
+  /// 1. As a Dart package in a directory which is a direct child of the
+  ///    packages directory. This is a plugin where all of the implementations
+  ///    exist in a single Dart package.
+  /// 2. Several plugin packages may live in a directory which is a direct
+  ///    child of the packages directory. This directory groups several Dart
+  ///    packages which implement a single plugin. This directory contains a
+  ///    "client library" package, which declares the API for the plugin, as
+  ///    well as one or more platform-specific implementations.
+  /// 3./4. Either of the above, but in a third_party/packages/ directory that
+  ///    is a sibling of the packages directory. This is used for a small number
+  ///    of packages in the flutter/packages repository.
+  Stream<Directory> _getAllPlugins() async* {
+    Set<String> plugins = Set<String>.from(getStringListArg(_pluginsArg));
+    final Set<String> excludedPlugins =
+        Set<String>.from(getStringListArg(_excludeArg));
+    final bool runOnChangedPackages = getBoolArg(_runOnChangedPackagesArg);
+    if (plugins.isEmpty &&
+        runOnChangedPackages &&
+        !(await _changesRequireFullTest())) {
+      plugins = await _getChangedPackages();
+    }
+
+    final Directory thirdPartyPackagesDirectory = packagesDir.parent
+        .childDirectory('third_party')
+        .childDirectory('packages');
+
+    for (final Directory dir in <Directory>[
+      packagesDir,
+      if (thirdPartyPackagesDirectory.existsSync()) thirdPartyPackagesDirectory,
+    ]) {
+      await for (final FileSystemEntity entity
+          in dir.list(followLinks: false)) {
+        // A top-level Dart package is a plugin package.
+        if (_isDartPackage(entity)) {
+          if (!excludedPlugins.contains(entity.basename) &&
+              (plugins.isEmpty || plugins.contains(p.basename(entity.path)))) {
+            yield entity as Directory;
+          }
+        } else if (entity is Directory) {
+          // Look for Dart packages under this top-level directory.
+          await for (final FileSystemEntity subdir
+              in entity.list(followLinks: false)) {
+            if (_isDartPackage(subdir)) {
+              // If --plugin=my_plugin is passed, then match all federated
+              // plugins under 'my_plugin'. Also match if the exact plugin is
+              // passed.
+              final String relativePath =
+                  p.relative(subdir.path, from: dir.path);
+              final String packageName = p.basename(subdir.path);
+              final String basenamePath = p.basename(entity.path);
+              if (!excludedPlugins.contains(basenamePath) &&
+                  !excludedPlugins.contains(packageName) &&
+                  !excludedPlugins.contains(relativePath) &&
+                  (plugins.isEmpty ||
+                      plugins.contains(relativePath) ||
+                      plugins.contains(basenamePath))) {
+                yield subdir as Directory;
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+
+  /// Returns the example Dart package folders of the plugins involved in this
+  /// command execution.
+  Stream<Directory> getExamples() =>
+      getPlugins().expand<Directory>(getExamplesForPlugin);
+
+  /// Returns all Dart package folders (typically, plugin + example) of the
+  /// plugins involved in this command execution.
+  Stream<Directory> getPackages() async* {
+    await for (final Directory plugin in getPlugins()) {
+      yield plugin;
+      yield* plugin
+          .list(recursive: true, followLinks: false)
+          .where(_isDartPackage)
+          .cast<Directory>();
+    }
+  }
+
+  /// Returns the files contained, recursively, within the plugins
+  /// involved in this command execution.
+  Stream<File> getFiles() {
+    return getPlugins().asyncExpand<File>((Directory folder) => folder
+        .list(recursive: true, followLinks: false)
+        .where((FileSystemEntity entity) => entity is File)
+        .cast<File>());
+  }
+
+  /// Returns whether the specified entity is a directory containing a
+  /// `pubspec.yaml` file.
+  bool _isDartPackage(FileSystemEntity entity) {
+    return entity is Directory && entity.childFile('pubspec.yaml').existsSync();
+  }
+
+  /// Returns the example Dart packages contained in the specified plugin, or
+  /// an empty List, if the plugin has no examples.
+  Iterable<Directory> getExamplesForPlugin(Directory plugin) {
+    final Directory exampleFolder = plugin.childDirectory('example');
+    if (!exampleFolder.existsSync()) {
+      return <Directory>[];
+    }
+    if (isFlutterPackage(exampleFolder)) {
+      return <Directory>[exampleFolder];
+    }
+    // Only look at the subdirectories of the example directory if the example
+    // directory itself is not a Dart package, and only look one level below the
+    // example directory for other dart packages.
+    return exampleFolder
+        .listSync()
+        .where((FileSystemEntity entity) => isFlutterPackage(entity))
+        .cast<Directory>();
+  }
+
+  /// Retrieve an instance of [GitVersionFinder] based on `_kBaseSha` and [gitDir].
+  ///
+  /// Throws tool exit if [gitDir] nor root directory is a git directory.
+  Future<GitVersionFinder> retrieveVersionFinder() async {
+    final String rootDir = packagesDir.parent.absolute.path;
+    final String baseSha = getStringArg(_kBaseSha);
+
+    GitDir? baseGitDir = gitDir;
+    if (baseGitDir == null) {
+      if (!await GitDir.isGitDir(rootDir)) {
+        printError(
+          '$rootDir is not a valid Git repository.',
+        );
+        throw ToolExit(2);
+      }
+      baseGitDir = await GitDir.fromExisting(rootDir);
+    }
+
+    final GitVersionFinder gitVersionFinder =
+        GitVersionFinder(baseGitDir, baseSha);
+    return gitVersionFinder;
+  }
+
+  // Returns packages that have been changed relative to the git base.
+  Future<Set<String>> _getChangedPackages() async {
+    final GitVersionFinder gitVersionFinder = await retrieveVersionFinder();
+
+    final List<String> allChangedFiles =
+        await gitVersionFinder.getChangedFiles();
+    final Set<String> packages = <String>{};
+    for (final String path in allChangedFiles) {
+      final List<String> pathComponents = path.split('/');
+      final int packagesIndex =
+          pathComponents.indexWhere((String element) => element == 'packages');
+      if (packagesIndex != -1) {
+        packages.add(pathComponents[packagesIndex + 1]);
+      }
+    }
+    if (packages.isEmpty) {
+      print('No changed packages.');
+    } else {
+      final String changedPackages = packages.join(',');
+      print('Changed packages: $changedPackages');
+    }
+    return packages;
+  }
+
+  // Returns true if one or more files changed that have the potential to affect
+  // any plugin (e.g., CI script changes).
+  Future<bool> _changesRequireFullTest() async {
+    final GitVersionFinder gitVersionFinder = await retrieveVersionFinder();
+
+    const List<String> specialFiles = <String>[
+      '.ci.yaml', // LUCI config.
+      '.cirrus.yml', // Cirrus config.
+      '.clang-format', // ObjC and C/C++ formatting options.
+      'analysis_options.yaml', // Dart analysis settings.
+    ];
+    const List<String> specialDirectories = <String>[
+      '.ci/', // Support files for CI.
+      'script/', // This tool, and its wrapper scripts.
+    ];
+    // Directory entries must end with / to avoid over-matching, since the
+    // check below is done via string prefixing.
+    assert(specialDirectories.every((String dir) => dir.endsWith('/')));
+
+    final List<String> allChangedFiles =
+        await gitVersionFinder.getChangedFiles();
+    return allChangedFiles.any((String path) =>
+        specialFiles.contains(path) ||
+        specialDirectories.any((String dir) => path.startsWith(dir)));
+  }
+}
diff --git a/script/tool/lib/src/common/plugin_utils.dart b/script/tool/lib/src/common/plugin_utils.dart
new file mode 100644
index 0000000..b6ac433
--- /dev/null
+++ b/script/tool/lib/src/common/plugin_utils.dart
@@ -0,0 +1,110 @@
+// 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 'package:file/file.dart';
+import 'package:yaml/yaml.dart';
+
+import 'core.dart';
+
+/// Possible plugin support options for a platform.
+enum PlatformSupport {
+  /// The platform has an implementation in the package.
+  inline,
+
+  /// The platform has an endorsed federated implementation in another package.
+  federated,
+}
+
+/// Returns whether the given directory contains a Flutter [platform] plugin.
+///
+/// It checks this by looking for the following pattern in the pubspec:
+///
+///     flutter:
+///       plugin:
+///         platforms:
+///           [platform]:
+///
+/// If [requiredMode] is provided, the plugin must have the given type of
+/// implementation in order to return true.
+bool pluginSupportsPlatform(String platform, FileSystemEntity entity,
+    {PlatformSupport? requiredMode}) {
+  assert(platform == kPlatformFlagIos ||
+      platform == kPlatformFlagAndroid ||
+      platform == kPlatformFlagWeb ||
+      platform == kPlatformFlagMacos ||
+      platform == kPlatformFlagWindows ||
+      platform == kPlatformFlagLinux);
+  if (entity is! Directory) {
+    return false;
+  }
+
+  try {
+    final File pubspecFile = entity.childFile('pubspec.yaml');
+    final YamlMap pubspecYaml =
+        loadYaml(pubspecFile.readAsStringSync()) as YamlMap;
+    final YamlMap? flutterSection = pubspecYaml['flutter'] as YamlMap?;
+    if (flutterSection == null) {
+      return false;
+    }
+    final YamlMap? pluginSection = flutterSection['plugin'] as YamlMap?;
+    if (pluginSection == null) {
+      return false;
+    }
+    final YamlMap? platforms = pluginSection['platforms'] as YamlMap?;
+    if (platforms == null) {
+      // Legacy plugin specs are assumed to support iOS and Android. They are
+      // never federated.
+      if (requiredMode == PlatformSupport.federated) {
+        return false;
+      }
+      if (!pluginSection.containsKey('platforms')) {
+        return platform == kPlatformFlagIos || platform == kPlatformFlagAndroid;
+      }
+      return false;
+    }
+    final YamlMap? platformEntry = platforms[platform] as YamlMap?;
+    if (platformEntry == null) {
+      return false;
+    }
+    // If the platform entry is present, then it supports the platform. Check
+    // for required mode if specified.
+    final bool federated = platformEntry.containsKey('default_package');
+    return requiredMode == null ||
+        federated == (requiredMode == PlatformSupport.federated);
+  } on FileSystemException {
+    return false;
+  } on YamlException {
+    return false;
+  }
+}
+
+/// Returns whether the given directory contains a Flutter Android plugin.
+bool isAndroidPlugin(FileSystemEntity entity) {
+  return pluginSupportsPlatform(kPlatformFlagAndroid, entity);
+}
+
+/// Returns whether the given directory contains a Flutter iOS plugin.
+bool isIosPlugin(FileSystemEntity entity) {
+  return pluginSupportsPlatform(kPlatformFlagIos, entity);
+}
+
+/// Returns whether the given directory contains a Flutter web plugin.
+bool isWebPlugin(FileSystemEntity entity) {
+  return pluginSupportsPlatform(kPlatformFlagWeb, entity);
+}
+
+/// Returns whether the given directory contains a Flutter Windows plugin.
+bool isWindowsPlugin(FileSystemEntity entity) {
+  return pluginSupportsPlatform(kPlatformFlagWindows, entity);
+}
+
+/// Returns whether the given directory contains a Flutter macOS plugin.
+bool isMacOsPlugin(FileSystemEntity entity) {
+  return pluginSupportsPlatform(kPlatformFlagMacos, entity);
+}
+
+/// Returns whether the given directory contains a Flutter linux plugin.
+bool isLinuxPlugin(FileSystemEntity entity) {
+  return pluginSupportsPlatform(kPlatformFlagLinux, entity);
+}
diff --git a/script/tool/lib/src/common/process_runner.dart b/script/tool/lib/src/common/process_runner.dart
new file mode 100644
index 0000000..429761e
--- /dev/null
+++ b/script/tool/lib/src/common/process_runner.dart
@@ -0,0 +1,104 @@
+// 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:convert';
+import 'dart:io' as io;
+
+import 'package:file/file.dart';
+
+import 'core.dart';
+
+/// A class used to run processes.
+///
+/// We use this instead of directly running the process so it can be overridden
+/// in tests.
+class ProcessRunner {
+  /// Creates a new process runner.
+  const ProcessRunner();
+
+  /// Run the [executable] with [args] and stream output to stderr and stdout.
+  ///
+  /// The current working directory of [executable] can be overridden by
+  /// passing [workingDir].
+  ///
+  /// If [exitOnError] is set to `true`, then this will throw an error if
+  /// the [executable] terminates with a non-zero exit code.
+  ///
+  /// Returns the exit code of the [executable].
+  Future<int> runAndStream(
+    String executable,
+    List<String> args, {
+    Directory? workingDir,
+    bool exitOnError = false,
+  }) async {
+    print(
+        'Running command: "$executable ${args.join(' ')}" in ${workingDir?.path ?? io.Directory.current.path}');
+    final io.Process process = await io.Process.start(executable, args,
+        workingDirectory: workingDir?.path);
+    await io.stdout.addStream(process.stdout);
+    await io.stderr.addStream(process.stderr);
+    if (exitOnError && await process.exitCode != 0) {
+      final String error =
+          _getErrorString(executable, args, workingDir: workingDir);
+      print('$error See above for details.');
+      throw ToolExit(await process.exitCode);
+    }
+    return process.exitCode;
+  }
+
+  /// Run the [executable] with [args].
+  ///
+  /// The current working directory of [executable] can be overridden by
+  /// passing [workingDir].
+  ///
+  /// If [exitOnError] is set to `true`, then this will throw an error if
+  /// the [executable] terminates with a non-zero exit code.
+  /// Defaults to `false`.
+  ///
+  /// If [logOnError] is set to `true`, it will print a formatted message about the error.
+  /// Defaults to `false`
+  ///
+  /// Returns the [io.ProcessResult] of the [executable].
+  Future<io.ProcessResult> run(String executable, List<String> args,
+      {Directory? workingDir,
+      bool exitOnError = false,
+      bool logOnError = false,
+      Encoding stdoutEncoding = io.systemEncoding,
+      Encoding stderrEncoding = io.systemEncoding}) async {
+    final io.ProcessResult result = await io.Process.run(executable, args,
+        workingDirectory: workingDir?.path,
+        stdoutEncoding: stdoutEncoding,
+        stderrEncoding: stderrEncoding);
+    if (result.exitCode != 0) {
+      if (logOnError) {
+        final String error =
+            _getErrorString(executable, args, workingDir: workingDir);
+        print('$error Stderr:\n${result.stdout}');
+      }
+      if (exitOnError) {
+        throw ToolExit(result.exitCode);
+      }
+    }
+    return result;
+  }
+
+  /// Starts the [executable] with [args].
+  ///
+  /// The current working directory of [executable] can be overridden by
+  /// passing [workingDir].
+  ///
+  /// Returns the started [io.Process].
+  Future<io.Process> start(String executable, List<String> args,
+      {Directory? workingDirectory}) async {
+    final io.Process process = await io.Process.start(executable, args,
+        workingDirectory: workingDirectory?.path);
+    return process;
+  }
+
+  String _getErrorString(String executable, List<String> args,
+      {Directory? workingDir}) {
+    final String workdir = workingDir == null ? '' : ' in ${workingDir.path}';
+    return 'ERROR: Unable to execute "$executable ${args.join(' ')}"$workdir.';
+  }
+}
diff --git a/script/tool/lib/src/common/pub_version_finder.dart b/script/tool/lib/src/common/pub_version_finder.dart
new file mode 100644
index 0000000..ebac473
--- /dev/null
+++ b/script/tool/lib/src/common/pub_version_finder.dart
@@ -0,0 +1,103 @@
+// 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:convert';
+
+import 'package:http/http.dart' as http;
+import 'package:pub_semver/pub_semver.dart';
+
+/// Finding version of [package] that is published on pub.
+class PubVersionFinder {
+  /// Constructor.
+  ///
+  /// Note: you should manually close the [httpClient] when done using the finder.
+  PubVersionFinder({this.pubHost = defaultPubHost, required this.httpClient});
+
+  /// The default pub host to use.
+  static const String defaultPubHost = 'https://pub.dev';
+
+  /// The pub host url, defaults to `https://pub.dev`.
+  final String pubHost;
+
+  /// The http client.
+  ///
+  /// You should manually close this client when done using this finder.
+  final http.Client httpClient;
+
+  /// Get the package version on pub.
+  Future<PubVersionFinderResponse> getPackageVersion(
+      {required String package}) async {
+    assert(package.isNotEmpty);
+    final Uri pubHostUri = Uri.parse(pubHost);
+    final Uri url = pubHostUri.replace(path: '/packages/$package.json');
+    final http.Response response = await httpClient.get(url);
+
+    if (response.statusCode == 404) {
+      return PubVersionFinderResponse(
+          versions: <Version>[],
+          result: PubVersionFinderResult.noPackageFound,
+          httpResponse: response);
+    } else if (response.statusCode != 200) {
+      return PubVersionFinderResponse(
+          versions: <Version>[],
+          result: PubVersionFinderResult.fail,
+          httpResponse: response);
+    }
+    final List<Version> versions =
+        (json.decode(response.body)['versions'] as List<dynamic>)
+            .map<Version>((final dynamic versionString) =>
+                Version.parse(versionString as String))
+            .toList();
+
+    return PubVersionFinderResponse(
+        versions: versions,
+        result: PubVersionFinderResult.success,
+        httpResponse: response);
+  }
+}
+
+/// Represents a response for [PubVersionFinder].
+class PubVersionFinderResponse {
+  /// Constructor.
+  PubVersionFinderResponse(
+      {required this.versions,
+      required this.result,
+      required this.httpResponse}) {
+    if (versions.isNotEmpty) {
+      versions.sort((Version a, Version b) {
+        // TODO(cyanglaz): Think about how to handle pre-release version with [Version.prioritize].
+        // https://github.com/flutter/flutter/issues/82222
+        return b.compareTo(a);
+      });
+    }
+  }
+
+  /// The versions found in [PubVersionFinder].
+  ///
+  /// This is sorted by largest to smallest, so the first element in the list is the largest version.
+  /// Might be `null` if the [result] is not [PubVersionFinderResult.success].
+  final List<Version> versions;
+
+  /// The result of the version finder.
+  final PubVersionFinderResult result;
+
+  /// The response object of the http request.
+  final http.Response httpResponse;
+}
+
+/// An enum representing the result of [PubVersionFinder].
+enum PubVersionFinderResult {
+  /// The version finder successfully found a version.
+  success,
+
+  /// The version finder failed to find a valid version.
+  ///
+  /// This might due to http connection errors or user errors.
+  fail,
+
+  /// The version finder failed to locate the package.
+  ///
+  /// This indicates the package is new.
+  noPackageFound,
+}
diff --git a/script/tool/lib/src/create_all_plugins_app_command.dart b/script/tool/lib/src/create_all_plugins_app_command.dart
index cd5b85e..fab41bc 100644
--- a/script/tool/lib/src/create_all_plugins_app_command.dart
+++ b/script/tool/lib/src/create_all_plugins_app_command.dart
@@ -8,7 +8,8 @@
 import 'package:pub_semver/pub_semver.dart';
 import 'package:pubspec_parse/pubspec_parse.dart';
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/plugin_command.dart';
 
 /// A command to create an application that builds all in a single application.
 class CreateAllPluginsAppCommand extends PluginCommand {
diff --git a/script/tool/lib/src/drive_examples_command.dart b/script/tool/lib/src/drive_examples_command.dart
index 14dfede..b6576cd 100644
--- a/script/tool/lib/src/drive_examples_command.dart
+++ b/script/tool/lib/src/drive_examples_command.dart
@@ -2,11 +2,14 @@
 // 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:path/path.dart' as p;
 import 'package:platform/platform.dart';
-import 'common.dart';
+
+import 'common/core.dart';
+import 'common/plugin_command.dart';
+import 'common/plugin_utils.dart';
+import 'common/process_runner.dart';
 
 /// A command to run the example applications for packages via Flutter driver.
 class DriveExamplesCommand extends PluginCommand {
diff --git a/script/tool/lib/src/firebase_test_lab_command.dart b/script/tool/lib/src/firebase_test_lab_command.dart
index 741d856..b4f5e92 100644
--- a/script/tool/lib/src/firebase_test_lab_command.dart
+++ b/script/tool/lib/src/firebase_test_lab_command.dart
@@ -9,7 +9,9 @@
 import 'package:path/path.dart' as p;
 import 'package:uuid/uuid.dart';
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/plugin_command.dart';
+import 'common/process_runner.dart';
 
 /// A command to run tests via Firebase test lab.
 class FirebaseTestLabCommand extends PluginCommand {
diff --git a/script/tool/lib/src/format_command.dart b/script/tool/lib/src/format_command.dart
index 1ef41f8..5f060d7 100644
--- a/script/tool/lib/src/format_command.dart
+++ b/script/tool/lib/src/format_command.dart
@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:async';
 import 'dart:convert';
 import 'dart:io' as io;
 
@@ -11,7 +10,9 @@
 import 'package:path/path.dart' as p;
 import 'package:quiver/iterables.dart';
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/plugin_command.dart';
+import 'common/process_runner.dart';
 
 final Uri _googleFormatterUrl = Uri.https('github.com',
     '/google/google-java-format/releases/download/google-java-format-1.3/google-java-format-1.3-all-deps.jar');
diff --git a/script/tool/lib/src/java_test_command.dart b/script/tool/lib/src/java_test_command.dart
index d1366ea..d7e453b 100644
--- a/script/tool/lib/src/java_test_command.dart
+++ b/script/tool/lib/src/java_test_command.dart
@@ -2,12 +2,12 @@
 // 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:path/path.dart' as p;
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/plugin_command.dart';
+import 'common/process_runner.dart';
 
 /// A command to run the Java tests of Android plugins.
 class JavaTestCommand extends PluginCommand {
diff --git a/script/tool/lib/src/license_check_command.dart b/script/tool/lib/src/license_check_command.dart
index 805c3ab..4ea8a1e 100644
--- a/script/tool/lib/src/license_check_command.dart
+++ b/script/tool/lib/src/license_check_command.dart
@@ -2,12 +2,11 @@
 // 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:path/path.dart' as p;
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/plugin_command.dart';
 
 const Set<String> _codeFileExtensions = <String>{
   '.c',
diff --git a/script/tool/lib/src/lint_podspecs_command.dart b/script/tool/lib/src/lint_podspecs_command.dart
index 364653b..5e86d2b 100644
--- a/script/tool/lib/src/lint_podspecs_command.dart
+++ b/script/tool/lib/src/lint_podspecs_command.dart
@@ -9,7 +9,9 @@
 import 'package:path/path.dart' as p;
 import 'package:platform/platform.dart';
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/plugin_command.dart';
+import 'common/process_runner.dart';
 
 /// Lint the CocoaPod podspecs and run unit tests.
 ///
diff --git a/script/tool/lib/src/list_command.dart b/script/tool/lib/src/list_command.dart
index f6b186e..39515cf 100644
--- a/script/tool/lib/src/list_command.dart
+++ b/script/tool/lib/src/list_command.dart
@@ -2,11 +2,9 @@
 // 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 'common.dart';
+import 'common/plugin_command.dart';
 
 /// A command to list different types of repository content.
 class ListCommand extends PluginCommand {
diff --git a/script/tool/lib/src/main.dart b/script/tool/lib/src/main.dart
index a760312..f397a04 100644
--- a/script/tool/lib/src/main.dart
+++ b/script/tool/lib/src/main.dart
@@ -10,7 +10,7 @@
 
 import 'analyze_command.dart';
 import 'build_examples_command.dart';
-import 'common.dart';
+import 'common/core.dart';
 import 'create_all_plugins_app_command.dart';
 import 'drive_examples_command.dart';
 import 'firebase_test_lab_command.dart';
diff --git a/script/tool/lib/src/publish_check_command.dart b/script/tool/lib/src/publish_check_command.dart
index b77ecee..82a7660 100644
--- a/script/tool/lib/src/publish_check_command.dart
+++ b/script/tool/lib/src/publish_check_command.dart
@@ -12,7 +12,10 @@
 import 'package:pub_semver/pub_semver.dart';
 import 'package:pubspec_parse/pubspec_parse.dart';
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/plugin_command.dart';
+import 'common/process_runner.dart';
+import 'common/pub_version_finder.dart';
 
 /// A command to check that packages are publishable via 'dart publish'.
 class PublishCheckCommand extends PluginCommand {
diff --git a/script/tool/lib/src/publish_plugin_command.dart b/script/tool/lib/src/publish_plugin_command.dart
index 1e7c150..70ec75b 100644
--- a/script/tool/lib/src/publish_plugin_command.dart
+++ b/script/tool/lib/src/publish_plugin_command.dart
@@ -14,7 +14,10 @@
 import 'package:pubspec_parse/pubspec_parse.dart';
 import 'package:yaml/yaml.dart';
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/git_version_finder.dart';
+import 'common/plugin_command.dart';
+import 'common/process_runner.dart';
 
 @immutable
 class _RemoteInfo {
diff --git a/script/tool/lib/src/pubspec_check_command.dart b/script/tool/lib/src/pubspec_check_command.dart
index 878b683..480d3a4 100644
--- a/script/tool/lib/src/pubspec_check_command.dart
+++ b/script/tool/lib/src/pubspec_check_command.dart
@@ -2,14 +2,14 @@
 // 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';
+import 'common/core.dart';
+import 'common/plugin_command.dart';
+import 'common/process_runner.dart';
 
 /// A command to enforce pubspec conventions across the repository.
 ///
diff --git a/script/tool/lib/src/test_command.dart b/script/tool/lib/src/test_command.dart
index 0174b98..b7bf261 100644
--- a/script/tool/lib/src/test_command.dart
+++ b/script/tool/lib/src/test_command.dart
@@ -2,12 +2,13 @@
 // 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:path/path.dart' as p;
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/plugin_command.dart';
+import 'common/plugin_utils.dart';
+import 'common/process_runner.dart';
 
 /// A command to run Dart unit tests for packages.
 class TestCommand extends PluginCommand {
diff --git a/script/tool/lib/src/version_check_command.dart b/script/tool/lib/src/version_check_command.dart
index 6baa38e..5e9f553 100644
--- a/script/tool/lib/src/version_check_command.dart
+++ b/script/tool/lib/src/version_check_command.dart
@@ -2,8 +2,6 @@
 // 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:http/http.dart' as http;
@@ -11,7 +9,11 @@
 import 'package:pub_semver/pub_semver.dart';
 import 'package:pubspec_parse/pubspec_parse.dart';
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/git_version_finder.dart';
+import 'common/plugin_command.dart';
+import 'common/process_runner.dart';
+import 'common/pub_version_finder.dart';
 
 /// Categories of version change types.
 enum NextVersionType {
diff --git a/script/tool/lib/src/xctest_command.dart b/script/tool/lib/src/xctest_command.dart
index 288851c..77e5659 100644
--- a/script/tool/lib/src/xctest_command.dart
+++ b/script/tool/lib/src/xctest_command.dart
@@ -2,14 +2,16 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:async';
 import 'dart:convert';
 import 'dart:io' as io;
 
 import 'package:file/file.dart';
 import 'package:path/path.dart' as p;
 
-import 'common.dart';
+import 'common/core.dart';
+import 'common/plugin_command.dart';
+import 'common/plugin_utils.dart';
+import 'common/process_runner.dart';
 
 const String _kiOSDestination = 'ios-destination';
 const String _kXcodeBuildCommand = 'xcodebuild';
diff --git a/script/tool/test/analyze_command_test.dart b/script/tool/test/analyze_command_test.dart
index ec627f2..1ef4fdc 100644
--- a/script/tool/test/analyze_command_test.dart
+++ b/script/tool/test/analyze_command_test.dart
@@ -6,7 +6,7 @@
 import 'package:file/file.dart';
 import 'package:file/memory.dart';
 import 'package:flutter_plugin_tools/src/analyze_command.dart';
-import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/common/core.dart';
 import 'package:test/test.dart';
 
 import 'mocks.dart';
diff --git a/script/tool/test/common/git_version_finder_test.dart b/script/tool/test/common/git_version_finder_test.dart
new file mode 100644
index 0000000..f1f40b5
--- /dev/null
+++ b/script/tool/test/common/git_version_finder_test.dart
@@ -0,0 +1,93 @@
+// 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:io';
+
+import 'package:flutter_plugin_tools/src/common/git_version_finder.dart';
+import 'package:mockito/mockito.dart';
+import 'package:test/test.dart';
+
+import 'plugin_command_test.mocks.dart';
+
+void main() {
+  late List<List<String>?> gitDirCommands;
+  late String gitDiffResponse;
+  late MockGitDir gitDir;
+  String? mergeBaseResponse;
+
+  setUp(() {
+    gitDirCommands = <List<String>?>[];
+    gitDiffResponse = '';
+    gitDir = MockGitDir();
+    when(gitDir.runCommand(any, throwOnError: anyNamed('throwOnError')))
+        .thenAnswer((Invocation invocation) {
+      gitDirCommands.add(invocation.positionalArguments[0] as List<String>?);
+      final MockProcessResult mockProcessResult = MockProcessResult();
+      if (invocation.positionalArguments[0][0] == 'diff') {
+        when<String?>(mockProcessResult.stdout as String?)
+            .thenReturn(gitDiffResponse);
+      } else if (invocation.positionalArguments[0][0] == 'merge-base') {
+        when<String?>(mockProcessResult.stdout as String?)
+            .thenReturn(mergeBaseResponse);
+      }
+      return Future<ProcessResult>.value(mockProcessResult);
+    });
+  });
+
+  test('No git diff should result no files changed', () async {
+    final GitVersionFinder finder = GitVersionFinder(gitDir, 'some base sha');
+    final List<String> changedFiles = await finder.getChangedFiles();
+
+    expect(changedFiles, isEmpty);
+  });
+
+  test('get correct files changed based on git diff', () async {
+    gitDiffResponse = '''
+file1/file1.cc
+file2/file2.cc
+''';
+    final GitVersionFinder finder = GitVersionFinder(gitDir, 'some base sha');
+    final List<String> changedFiles = await finder.getChangedFiles();
+
+    expect(changedFiles, equals(<String>['file1/file1.cc', 'file2/file2.cc']));
+  });
+
+  test('get correct pubspec change based on git diff', () async {
+    gitDiffResponse = '''
+file1/pubspec.yaml
+file2/file2.cc
+''';
+    final GitVersionFinder finder = GitVersionFinder(gitDir, 'some base sha');
+    final List<String> changedFiles = await finder.getChangedPubSpecs();
+
+    expect(changedFiles, equals(<String>['file1/pubspec.yaml']));
+  });
+
+  test('use correct base sha if not specified', () async {
+    mergeBaseResponse = 'shaqwiueroaaidf12312jnadf123nd';
+    gitDiffResponse = '''
+file1/pubspec.yaml
+file2/file2.cc
+''';
+
+    final GitVersionFinder finder = GitVersionFinder(gitDir, null);
+    await finder.getChangedFiles();
+    verify(gitDir.runCommand(
+        <String>['diff', '--name-only', mergeBaseResponse!, 'HEAD']));
+  });
+
+  test('use correct base sha if specified', () async {
+    const String customBaseSha = 'aklsjdcaskf12312';
+    gitDiffResponse = '''
+file1/pubspec.yaml
+file2/file2.cc
+''';
+    final GitVersionFinder finder = GitVersionFinder(gitDir, customBaseSha);
+    await finder.getChangedFiles();
+    verify(gitDir
+        .runCommand(<String>['diff', '--name-only', customBaseSha, 'HEAD']));
+  });
+}
+
+class MockProcessResult extends Mock implements ProcessResult {}
diff --git a/script/tool/test/common/plugin_command_test.dart b/script/tool/test/common/plugin_command_test.dart
new file mode 100644
index 0000000..58d202e
--- /dev/null
+++ b/script/tool/test/common/plugin_command_test.dart
@@ -0,0 +1,387 @@
+// 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:io';
+
+import 'package:args/command_runner.dart';
+import 'package:file/file.dart';
+import 'package:file/memory.dart';
+import 'package:flutter_plugin_tools/src/common/plugin_command.dart';
+import 'package:flutter_plugin_tools/src/common/process_runner.dart';
+import 'package:git/git.dart';
+import 'package:mockito/annotations.dart';
+import 'package:mockito/mockito.dart';
+import 'package:test/test.dart';
+
+import '../util.dart';
+import 'plugin_command_test.mocks.dart';
+
+@GenerateMocks(<Type>[GitDir])
+void main() {
+  late RecordingProcessRunner processRunner;
+  late CommandRunner<void> runner;
+  late FileSystem fileSystem;
+  late Directory packagesDir;
+  late Directory thirdPartyPackagesDir;
+  late List<String> plugins;
+  late List<List<String>?> gitDirCommands;
+  late String gitDiffResponse;
+
+  setUp(() {
+    fileSystem = MemoryFileSystem();
+    packagesDir = createPackagesDirectory(fileSystem: fileSystem);
+    thirdPartyPackagesDir = packagesDir.parent
+        .childDirectory('third_party')
+        .childDirectory('packages');
+
+    gitDirCommands = <List<String>?>[];
+    gitDiffResponse = '';
+    final MockGitDir gitDir = MockGitDir();
+    when(gitDir.runCommand(any, throwOnError: anyNamed('throwOnError')))
+        .thenAnswer((Invocation invocation) {
+      gitDirCommands.add(invocation.positionalArguments[0] as List<String>?);
+      final MockProcessResult mockProcessResult = MockProcessResult();
+      if (invocation.positionalArguments[0][0] == 'diff') {
+        when<String?>(mockProcessResult.stdout as String?)
+            .thenReturn(gitDiffResponse);
+      }
+      return Future<ProcessResult>.value(mockProcessResult);
+    });
+    processRunner = RecordingProcessRunner();
+    plugins = <String>[];
+    final SamplePluginCommand samplePluginCommand = SamplePluginCommand(
+      plugins,
+      packagesDir,
+      processRunner: processRunner,
+      gitDir: gitDir,
+    );
+    runner =
+        CommandRunner<void>('common_command', 'Test for common functionality');
+    runner.addCommand(samplePluginCommand);
+  });
+
+  group('plugin iteration', () {
+    test('all plugins from file system', () async {
+      final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+      final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+      await runner.run(<String>['sample']);
+      expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
+    });
+
+    test('all plugins includes third_party/packages', () async {
+      final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+      final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+      final Directory plugin3 =
+          createFakePlugin('plugin3', thirdPartyPackagesDir);
+      await runner.run(<String>['sample']);
+      expect(plugins,
+          unorderedEquals(<String>[plugin1.path, plugin2.path, plugin3.path]));
+    });
+
+    test('exclude plugins when plugins flag is specified', () async {
+      createFakePlugin('plugin1', packagesDir);
+      final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+      await runner.run(
+          <String>['sample', '--plugins=plugin1,plugin2', '--exclude=plugin1']);
+      expect(plugins, unorderedEquals(<String>[plugin2.path]));
+    });
+
+    test('exclude plugins when plugins flag isn\'t specified', () async {
+      createFakePlugin('plugin1', packagesDir);
+      createFakePlugin('plugin2', packagesDir);
+      await runner.run(<String>['sample', '--exclude=plugin1,plugin2']);
+      expect(plugins, unorderedEquals(<String>[]));
+    });
+
+    test('exclude federated plugins when plugins flag is specified', () async {
+      createFakePlugin('plugin1', packagesDir,
+          parentDirectoryName: 'federated');
+      final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+      await runner.run(<String>[
+        'sample',
+        '--plugins=federated/plugin1,plugin2',
+        '--exclude=federated/plugin1'
+      ]);
+      expect(plugins, unorderedEquals(<String>[plugin2.path]));
+    });
+
+    test('exclude entire federated plugins when plugins flag is specified',
+        () async {
+      createFakePlugin('plugin1', packagesDir,
+          parentDirectoryName: 'federated');
+      final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+      await runner.run(<String>[
+        'sample',
+        '--plugins=federated/plugin1,plugin2',
+        '--exclude=federated'
+      ]);
+      expect(plugins, unorderedEquals(<String>[plugin2.path]));
+    });
+
+    group('test run-on-changed-packages', () {
+      test('all plugins should be tested if there are no changes.', () async {
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
+      });
+
+      test(
+          'all plugins should be tested if there are no plugin related changes.',
+          () async {
+        gitDiffResponse = 'AUTHORS';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
+      });
+
+      test('all plugins should be tested if .cirrus.yml changes.', () async {
+        gitDiffResponse = '''
+.cirrus.yml
+packages/plugin1/CHANGELOG
+''';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
+      });
+
+      test('all plugins should be tested if .ci.yaml changes', () async {
+        gitDiffResponse = '''
+.ci.yaml
+packages/plugin1/CHANGELOG
+''';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
+      });
+
+      test('all plugins should be tested if anything in .ci/ changes',
+          () async {
+        gitDiffResponse = '''
+.ci/Dockerfile
+packages/plugin1/CHANGELOG
+''';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
+      });
+
+      test('all plugins should be tested if anything in script changes.',
+          () async {
+        gitDiffResponse = '''
+script/tool_runner.sh
+packages/plugin1/CHANGELOG
+''';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
+      });
+
+      test('all plugins should be tested if the root analysis options change.',
+          () async {
+        gitDiffResponse = '''
+analysis_options.yaml
+packages/plugin1/CHANGELOG
+''';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
+      });
+
+      test('all plugins should be tested if formatting options change.',
+          () async {
+        gitDiffResponse = '''
+.clang-format
+packages/plugin1/CHANGELOG
+''';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
+      });
+
+      test('Only changed plugin should be tested.', () async {
+        gitDiffResponse = 'packages/plugin1/plugin1.dart';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+        createFakePlugin('plugin2', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path]));
+      });
+
+      test('multiple files in one plugin should also test the plugin',
+          () async {
+        gitDiffResponse = '''
+packages/plugin1/plugin1.dart
+packages/plugin1/ios/plugin1.m
+''';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+        createFakePlugin('plugin2', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path]));
+      });
+
+      test('multiple plugins changed should test all the changed plugins',
+          () async {
+        gitDiffResponse = '''
+packages/plugin1/plugin1.dart
+packages/plugin2/ios/plugin2.m
+''';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
+        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+        createFakePlugin('plugin3', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
+      });
+
+      test(
+          'multiple plugins inside the same plugin group changed should output the plugin group name',
+          () async {
+        gitDiffResponse = '''
+packages/plugin1/plugin1/plugin1.dart
+packages/plugin1/plugin1_platform_interface/plugin1_platform_interface.dart
+packages/plugin1/plugin1_web/plugin1_web.dart
+''';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir,
+            parentDirectoryName: 'plugin1');
+        createFakePlugin('plugin2', packagesDir);
+        createFakePlugin('plugin3', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path]));
+      });
+
+      test('--plugins flag overrides the behavior of --run-on-changed-packages',
+          () async {
+        gitDiffResponse = '''
+packages/plugin1/plugin1.dart
+packages/plugin2/ios/plugin2.m
+packages/plugin3/plugin3.dart
+''';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir,
+            parentDirectoryName: 'plugin1');
+        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
+        createFakePlugin('plugin3', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--plugins=plugin1,plugin2',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
+      });
+
+      test('--exclude flag works with --run-on-changed-packages', () async {
+        gitDiffResponse = '''
+packages/plugin1/plugin1.dart
+packages/plugin2/ios/plugin2.m
+packages/plugin3/plugin3.dart
+''';
+        final Directory plugin1 = createFakePlugin('plugin1', packagesDir,
+            parentDirectoryName: 'plugin1');
+        createFakePlugin('plugin2', packagesDir);
+        createFakePlugin('plugin3', packagesDir);
+        await runner.run(<String>[
+          'sample',
+          '--exclude=plugin2,plugin3',
+          '--base-sha=master',
+          '--run-on-changed-packages'
+        ]);
+
+        expect(plugins, unorderedEquals(<String>[plugin1.path]));
+      });
+    });
+  });
+}
+
+class SamplePluginCommand extends PluginCommand {
+  SamplePluginCommand(
+    this._plugins,
+    Directory packagesDir, {
+    ProcessRunner processRunner = const ProcessRunner(),
+    GitDir? gitDir,
+  }) : super(packagesDir, processRunner: processRunner, gitDir: gitDir);
+
+  final List<String> _plugins;
+
+  @override
+  final String name = 'sample';
+
+  @override
+  final String description = 'sample command';
+
+  @override
+  Future<void> run() async {
+    await for (final Directory package in getPlugins()) {
+      _plugins.add(package.path);
+    }
+  }
+}
+
+class MockProcessResult extends Mock implements ProcessResult {}
diff --git a/script/tool/test/common_test.mocks.dart b/script/tool/test/common/plugin_command_test.mocks.dart
similarity index 100%
rename from script/tool/test/common_test.mocks.dart
rename to script/tool/test/common/plugin_command_test.mocks.dart
diff --git a/script/tool/test/common/plugin_utils_test.dart b/script/tool/test/common/plugin_utils_test.dart
new file mode 100644
index 0000000..aaa8501
--- /dev/null
+++ b/script/tool/test/common/plugin_utils_test.dart
@@ -0,0 +1,210 @@
+// 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 'package:file/file.dart';
+import 'package:file/memory.dart';
+import 'package:flutter_plugin_tools/src/common/plugin_utils.dart';
+import 'package:test/test.dart';
+
+import '../util.dart';
+
+void main() {
+  late FileSystem fileSystem;
+  late Directory packagesDir;
+
+  setUp(() {
+    fileSystem = MemoryFileSystem();
+    packagesDir = createPackagesDirectory(fileSystem: fileSystem);
+  });
+
+  group('pluginSupportsPlatform', () {
+    test('no platforms', () async {
+      final Directory plugin = createFakePlugin('plugin', packagesDir);
+
+      expect(pluginSupportsPlatform('android', plugin), isFalse);
+      expect(pluginSupportsPlatform('ios', plugin), isFalse);
+      expect(pluginSupportsPlatform('linux', plugin), isFalse);
+      expect(pluginSupportsPlatform('macos', plugin), isFalse);
+      expect(pluginSupportsPlatform('web', plugin), isFalse);
+      expect(pluginSupportsPlatform('windows', plugin), isFalse);
+    });
+
+    test('all platforms', () async {
+      final Directory plugin = createFakePlugin(
+        'plugin',
+        packagesDir,
+        isAndroidPlugin: true,
+        isIosPlugin: true,
+        isLinuxPlugin: true,
+        isMacOsPlugin: true,
+        isWebPlugin: true,
+        isWindowsPlugin: true,
+      );
+
+      expect(pluginSupportsPlatform('android', plugin), isTrue);
+      expect(pluginSupportsPlatform('ios', plugin), isTrue);
+      expect(pluginSupportsPlatform('linux', plugin), isTrue);
+      expect(pluginSupportsPlatform('macos', plugin), isTrue);
+      expect(pluginSupportsPlatform('web', plugin), isTrue);
+      expect(pluginSupportsPlatform('windows', plugin), isTrue);
+    });
+
+    test('some platforms', () async {
+      final Directory plugin = createFakePlugin(
+        'plugin',
+        packagesDir,
+        isAndroidPlugin: true,
+        isIosPlugin: false,
+        isLinuxPlugin: true,
+        isMacOsPlugin: false,
+        isWebPlugin: true,
+        isWindowsPlugin: false,
+      );
+
+      expect(pluginSupportsPlatform('android', plugin), isTrue);
+      expect(pluginSupportsPlatform('ios', plugin), isFalse);
+      expect(pluginSupportsPlatform('linux', plugin), isTrue);
+      expect(pluginSupportsPlatform('macos', plugin), isFalse);
+      expect(pluginSupportsPlatform('web', plugin), isTrue);
+      expect(pluginSupportsPlatform('windows', plugin), isFalse);
+    });
+
+    test('inline plugins are only detected as inline', () async {
+      // createFakePlugin makes non-federated pubspec entries.
+      final Directory plugin = createFakePlugin(
+        'plugin',
+        packagesDir,
+        isAndroidPlugin: true,
+        isIosPlugin: true,
+        isLinuxPlugin: true,
+        isMacOsPlugin: true,
+        isWebPlugin: true,
+        isWindowsPlugin: true,
+      );
+
+      expect(
+          pluginSupportsPlatform('android', plugin,
+              requiredMode: PlatformSupport.inline),
+          isTrue);
+      expect(
+          pluginSupportsPlatform('android', plugin,
+              requiredMode: PlatformSupport.federated),
+          isFalse);
+      expect(
+          pluginSupportsPlatform('ios', plugin,
+              requiredMode: PlatformSupport.inline),
+          isTrue);
+      expect(
+          pluginSupportsPlatform('ios', plugin,
+              requiredMode: PlatformSupport.federated),
+          isFalse);
+      expect(
+          pluginSupportsPlatform('linux', plugin,
+              requiredMode: PlatformSupport.inline),
+          isTrue);
+      expect(
+          pluginSupportsPlatform('linux', plugin,
+              requiredMode: PlatformSupport.federated),
+          isFalse);
+      expect(
+          pluginSupportsPlatform('macos', plugin,
+              requiredMode: PlatformSupport.inline),
+          isTrue);
+      expect(
+          pluginSupportsPlatform('macos', plugin,
+              requiredMode: PlatformSupport.federated),
+          isFalse);
+      expect(
+          pluginSupportsPlatform('web', plugin,
+              requiredMode: PlatformSupport.inline),
+          isTrue);
+      expect(
+          pluginSupportsPlatform('web', plugin,
+              requiredMode: PlatformSupport.federated),
+          isFalse);
+      expect(
+          pluginSupportsPlatform('windows', plugin,
+              requiredMode: PlatformSupport.inline),
+          isTrue);
+      expect(
+          pluginSupportsPlatform('windows', plugin,
+              requiredMode: PlatformSupport.federated),
+          isFalse);
+    });
+
+    test('federated plugins are only detected as federated', () async {
+      const String pluginName = 'plugin';
+      final Directory plugin = createFakePlugin(
+        pluginName,
+        packagesDir,
+        isAndroidPlugin: true,
+        isIosPlugin: true,
+        isLinuxPlugin: true,
+        isMacOsPlugin: true,
+        isWebPlugin: true,
+        isWindowsPlugin: true,
+      );
+
+      createFakePubspec(
+        plugin,
+        name: pluginName,
+        androidSupport: PlatformSupport.federated,
+        iosSupport: PlatformSupport.federated,
+        linuxSupport: PlatformSupport.federated,
+        macosSupport: PlatformSupport.federated,
+        webSupport: PlatformSupport.federated,
+        windowsSupport: PlatformSupport.federated,
+      );
+
+      expect(
+          pluginSupportsPlatform('android', plugin,
+              requiredMode: PlatformSupport.federated),
+          isTrue);
+      expect(
+          pluginSupportsPlatform('android', plugin,
+              requiredMode: PlatformSupport.inline),
+          isFalse);
+      expect(
+          pluginSupportsPlatform('ios', plugin,
+              requiredMode: PlatformSupport.federated),
+          isTrue);
+      expect(
+          pluginSupportsPlatform('ios', plugin,
+              requiredMode: PlatformSupport.inline),
+          isFalse);
+      expect(
+          pluginSupportsPlatform('linux', plugin,
+              requiredMode: PlatformSupport.federated),
+          isTrue);
+      expect(
+          pluginSupportsPlatform('linux', plugin,
+              requiredMode: PlatformSupport.inline),
+          isFalse);
+      expect(
+          pluginSupportsPlatform('macos', plugin,
+              requiredMode: PlatformSupport.federated),
+          isTrue);
+      expect(
+          pluginSupportsPlatform('macos', plugin,
+              requiredMode: PlatformSupport.inline),
+          isFalse);
+      expect(
+          pluginSupportsPlatform('web', plugin,
+              requiredMode: PlatformSupport.federated),
+          isTrue);
+      expect(
+          pluginSupportsPlatform('web', plugin,
+              requiredMode: PlatformSupport.inline),
+          isFalse);
+      expect(
+          pluginSupportsPlatform('windows', plugin,
+              requiredMode: PlatformSupport.federated),
+          isTrue);
+      expect(
+          pluginSupportsPlatform('windows', plugin,
+              requiredMode: PlatformSupport.inline),
+          isFalse);
+    });
+  });
+}
diff --git a/script/tool/test/common/pub_version_finder_test.dart b/script/tool/test/common/pub_version_finder_test.dart
new file mode 100644
index 0000000..7d8658a
--- /dev/null
+++ b/script/tool/test/common/pub_version_finder_test.dart
@@ -0,0 +1,89 @@
+// 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:convert';
+import 'dart:io';
+
+import 'package:flutter_plugin_tools/src/common/pub_version_finder.dart';
+import 'package:http/http.dart' as http;
+import 'package:http/testing.dart';
+import 'package:mockito/mockito.dart';
+import 'package:pub_semver/pub_semver.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('Package does not exist.', () async {
+    final MockClient mockClient = MockClient((http.Request request) async {
+      return http.Response('', 404);
+    });
+    final PubVersionFinder finder = PubVersionFinder(httpClient: mockClient);
+    final PubVersionFinderResponse response =
+        await finder.getPackageVersion(package: 'some_package');
+
+    expect(response.versions, isEmpty);
+    expect(response.result, PubVersionFinderResult.noPackageFound);
+    expect(response.httpResponse.statusCode, 404);
+    expect(response.httpResponse.body, '');
+  });
+
+  test('HTTP error when getting versions from pub', () async {
+    final MockClient mockClient = MockClient((http.Request request) async {
+      return http.Response('', 400);
+    });
+    final PubVersionFinder finder = PubVersionFinder(httpClient: mockClient);
+    final PubVersionFinderResponse response =
+        await finder.getPackageVersion(package: 'some_package');
+
+    expect(response.versions, isEmpty);
+    expect(response.result, PubVersionFinderResult.fail);
+    expect(response.httpResponse.statusCode, 400);
+    expect(response.httpResponse.body, '');
+  });
+
+  test('Get a correct list of versions when http response is OK.', () async {
+    const Map<String, dynamic> httpResponse = <String, dynamic>{
+      'name': 'some_package',
+      'versions': <String>[
+        '0.0.1',
+        '0.0.2',
+        '0.0.2+2',
+        '0.1.1',
+        '0.0.1+1',
+        '0.1.0',
+        '0.2.0',
+        '0.1.0+1',
+        '0.0.2+1',
+        '2.0.0',
+        '1.2.0',
+        '1.0.0',
+      ],
+    };
+    final MockClient mockClient = MockClient((http.Request request) async {
+      return http.Response(json.encode(httpResponse), 200);
+    });
+    final PubVersionFinder finder = PubVersionFinder(httpClient: mockClient);
+    final PubVersionFinderResponse response =
+        await finder.getPackageVersion(package: 'some_package');
+
+    expect(response.versions, <Version>[
+      Version.parse('2.0.0'),
+      Version.parse('1.2.0'),
+      Version.parse('1.0.0'),
+      Version.parse('0.2.0'),
+      Version.parse('0.1.1'),
+      Version.parse('0.1.0+1'),
+      Version.parse('0.1.0'),
+      Version.parse('0.0.2+2'),
+      Version.parse('0.0.2+1'),
+      Version.parse('0.0.2'),
+      Version.parse('0.0.1+1'),
+      Version.parse('0.0.1'),
+    ]);
+    expect(response.result, PubVersionFinderResult.success);
+    expect(response.httpResponse.statusCode, 200);
+    expect(response.httpResponse.body, json.encode(httpResponse));
+  });
+}
+
+class MockProcessResult extends Mock implements ProcessResult {}
diff --git a/script/tool/test/common_test.dart b/script/tool/test/common_test.dart
deleted file mode 100644
index a51182d..0000000
--- a/script/tool/test/common_test.dart
+++ /dev/null
@@ -1,740 +0,0 @@
-// 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 'dart:convert';
-import 'dart:io';
-
-import 'package:args/command_runner.dart';
-import 'package:file/file.dart';
-import 'package:file/memory.dart';
-import 'package:flutter_plugin_tools/src/common.dart';
-import 'package:git/git.dart';
-import 'package:http/http.dart' as http;
-import 'package:http/testing.dart';
-import 'package:mockito/annotations.dart';
-import 'package:mockito/mockito.dart';
-import 'package:pub_semver/pub_semver.dart';
-import 'package:test/test.dart';
-
-import 'common_test.mocks.dart';
-import 'util.dart';
-
-@GenerateMocks(<Type>[GitDir])
-void main() {
-  late RecordingProcessRunner processRunner;
-  late CommandRunner<void> runner;
-  late FileSystem fileSystem;
-  late Directory packagesDir;
-  late Directory thirdPartyPackagesDir;
-  late List<String> plugins;
-  late List<List<String>?> gitDirCommands;
-  late String gitDiffResponse;
-
-  setUp(() {
-    fileSystem = MemoryFileSystem();
-    packagesDir = createPackagesDirectory(fileSystem: fileSystem);
-    thirdPartyPackagesDir = packagesDir.parent
-        .childDirectory('third_party')
-        .childDirectory('packages');
-
-    gitDirCommands = <List<String>?>[];
-    gitDiffResponse = '';
-    final MockGitDir gitDir = MockGitDir();
-    when(gitDir.runCommand(any, throwOnError: anyNamed('throwOnError')))
-        .thenAnswer((Invocation invocation) {
-      gitDirCommands.add(invocation.positionalArguments[0] as List<String>?);
-      final MockProcessResult mockProcessResult = MockProcessResult();
-      if (invocation.positionalArguments[0][0] == 'diff') {
-        when<String?>(mockProcessResult.stdout as String?)
-            .thenReturn(gitDiffResponse);
-      }
-      return Future<ProcessResult>.value(mockProcessResult);
-    });
-    processRunner = RecordingProcessRunner();
-    plugins = <String>[];
-    final SamplePluginCommand samplePluginCommand = SamplePluginCommand(
-      plugins,
-      packagesDir,
-      processRunner: processRunner,
-      gitDir: gitDir,
-    );
-    runner =
-        CommandRunner<void>('common_command', 'Test for common functionality');
-    runner.addCommand(samplePluginCommand);
-  });
-
-  group('plugin iteration', () {
-    test('all plugins from file system', () async {
-      final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-      final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-      await runner.run(<String>['sample']);
-      expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
-    });
-
-    test('all plugins includes third_party/packages', () async {
-      final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-      final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-      final Directory plugin3 =
-          createFakePlugin('plugin3', thirdPartyPackagesDir);
-      await runner.run(<String>['sample']);
-      expect(plugins,
-          unorderedEquals(<String>[plugin1.path, plugin2.path, plugin3.path]));
-    });
-
-    test('exclude plugins when plugins flag is specified', () async {
-      createFakePlugin('plugin1', packagesDir);
-      final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-      await runner.run(
-          <String>['sample', '--plugins=plugin1,plugin2', '--exclude=plugin1']);
-      expect(plugins, unorderedEquals(<String>[plugin2.path]));
-    });
-
-    test('exclude plugins when plugins flag isn\'t specified', () async {
-      createFakePlugin('plugin1', packagesDir);
-      createFakePlugin('plugin2', packagesDir);
-      await runner.run(<String>['sample', '--exclude=plugin1,plugin2']);
-      expect(plugins, unorderedEquals(<String>[]));
-    });
-
-    test('exclude federated plugins when plugins flag is specified', () async {
-      createFakePlugin('plugin1', packagesDir,
-          parentDirectoryName: 'federated');
-      final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-      await runner.run(<String>[
-        'sample',
-        '--plugins=federated/plugin1,plugin2',
-        '--exclude=federated/plugin1'
-      ]);
-      expect(plugins, unorderedEquals(<String>[plugin2.path]));
-    });
-
-    test('exclude entire federated plugins when plugins flag is specified',
-        () async {
-      createFakePlugin('plugin1', packagesDir,
-          parentDirectoryName: 'federated');
-      final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-      await runner.run(<String>[
-        'sample',
-        '--plugins=federated/plugin1,plugin2',
-        '--exclude=federated'
-      ]);
-      expect(plugins, unorderedEquals(<String>[plugin2.path]));
-    });
-
-    group('test run-on-changed-packages', () {
-      test('all plugins should be tested if there are no changes.', () async {
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
-      });
-
-      test(
-          'all plugins should be tested if there are no plugin related changes.',
-          () async {
-        gitDiffResponse = 'AUTHORS';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
-      });
-
-      test('all plugins should be tested if .cirrus.yml changes.', () async {
-        gitDiffResponse = '''
-.cirrus.yml
-packages/plugin1/CHANGELOG
-''';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
-      });
-
-      test('all plugins should be tested if .ci.yaml changes', () async {
-        gitDiffResponse = '''
-.ci.yaml
-packages/plugin1/CHANGELOG
-''';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
-      });
-
-      test('all plugins should be tested if anything in .ci/ changes',
-          () async {
-        gitDiffResponse = '''
-.ci/Dockerfile
-packages/plugin1/CHANGELOG
-''';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
-      });
-
-      test('all plugins should be tested if anything in script changes.',
-          () async {
-        gitDiffResponse = '''
-script/tool_runner.sh
-packages/plugin1/CHANGELOG
-''';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
-      });
-
-      test('all plugins should be tested if the root analysis options change.',
-          () async {
-        gitDiffResponse = '''
-analysis_options.yaml
-packages/plugin1/CHANGELOG
-''';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
-      });
-
-      test('all plugins should be tested if formatting options change.',
-          () async {
-        gitDiffResponse = '''
-.clang-format
-packages/plugin1/CHANGELOG
-''';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
-      });
-
-      test('Only changed plugin should be tested.', () async {
-        gitDiffResponse = 'packages/plugin1/plugin1.dart';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-        createFakePlugin('plugin2', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path]));
-      });
-
-      test('multiple files in one plugin should also test the plugin',
-          () async {
-        gitDiffResponse = '''
-packages/plugin1/plugin1.dart
-packages/plugin1/ios/plugin1.m
-''';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-        createFakePlugin('plugin2', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path]));
-      });
-
-      test('multiple plugins changed should test all the changed plugins',
-          () async {
-        gitDiffResponse = '''
-packages/plugin1/plugin1.dart
-packages/plugin2/ios/plugin2.m
-''';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir);
-        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-        createFakePlugin('plugin3', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
-      });
-
-      test(
-          'multiple plugins inside the same plugin group changed should output the plugin group name',
-          () async {
-        gitDiffResponse = '''
-packages/plugin1/plugin1/plugin1.dart
-packages/plugin1/plugin1_platform_interface/plugin1_platform_interface.dart
-packages/plugin1/plugin1_web/plugin1_web.dart
-''';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir,
-            parentDirectoryName: 'plugin1');
-        createFakePlugin('plugin2', packagesDir);
-        createFakePlugin('plugin3', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path]));
-      });
-
-      test('--plugins flag overrides the behavior of --run-on-changed-packages',
-          () async {
-        gitDiffResponse = '''
-packages/plugin1/plugin1.dart
-packages/plugin2/ios/plugin2.m
-packages/plugin3/plugin3.dart
-''';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir,
-            parentDirectoryName: 'plugin1');
-        final Directory plugin2 = createFakePlugin('plugin2', packagesDir);
-        createFakePlugin('plugin3', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--plugins=plugin1,plugin2',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path, plugin2.path]));
-      });
-
-      test('--exclude flag works with --run-on-changed-packages', () async {
-        gitDiffResponse = '''
-packages/plugin1/plugin1.dart
-packages/plugin2/ios/plugin2.m
-packages/plugin3/plugin3.dart
-''';
-        final Directory plugin1 = createFakePlugin('plugin1', packagesDir,
-            parentDirectoryName: 'plugin1');
-        createFakePlugin('plugin2', packagesDir);
-        createFakePlugin('plugin3', packagesDir);
-        await runner.run(<String>[
-          'sample',
-          '--exclude=plugin2,plugin3',
-          '--base-sha=master',
-          '--run-on-changed-packages'
-        ]);
-
-        expect(plugins, unorderedEquals(<String>[plugin1.path]));
-      });
-    });
-  });
-
-  group('$GitVersionFinder', () {
-    late FileSystem fileSystem;
-    late List<List<String>?> gitDirCommands;
-    late String gitDiffResponse;
-    String? mergeBaseResponse;
-    late MockGitDir gitDir;
-
-    setUp(() {
-      fileSystem = MemoryFileSystem();
-      createPackagesDirectory(fileSystem: fileSystem);
-      gitDirCommands = <List<String>?>[];
-      gitDiffResponse = '';
-      gitDir = MockGitDir();
-      when(gitDir.runCommand(any, throwOnError: anyNamed('throwOnError')))
-          .thenAnswer((Invocation invocation) {
-        gitDirCommands.add(invocation.positionalArguments[0] as List<String>?);
-        final MockProcessResult mockProcessResult = MockProcessResult();
-        if (invocation.positionalArguments[0][0] == 'diff') {
-          when<String?>(mockProcessResult.stdout as String?)
-              .thenReturn(gitDiffResponse);
-        } else if (invocation.positionalArguments[0][0] == 'merge-base') {
-          when<String?>(mockProcessResult.stdout as String?)
-              .thenReturn(mergeBaseResponse);
-        }
-        return Future<ProcessResult>.value(mockProcessResult);
-      });
-      processRunner = RecordingProcessRunner();
-    });
-
-    test('No git diff should result no files changed', () async {
-      final GitVersionFinder finder = GitVersionFinder(gitDir, 'some base sha');
-      final List<String> changedFiles = await finder.getChangedFiles();
-
-      expect(changedFiles, isEmpty);
-    });
-
-    test('get correct files changed based on git diff', () async {
-      gitDiffResponse = '''
-file1/file1.cc
-file2/file2.cc
-''';
-      final GitVersionFinder finder = GitVersionFinder(gitDir, 'some base sha');
-      final List<String> changedFiles = await finder.getChangedFiles();
-
-      expect(
-          changedFiles, equals(<String>['file1/file1.cc', 'file2/file2.cc']));
-    });
-
-    test('get correct pubspec change based on git diff', () async {
-      gitDiffResponse = '''
-file1/pubspec.yaml
-file2/file2.cc
-''';
-      final GitVersionFinder finder = GitVersionFinder(gitDir, 'some base sha');
-      final List<String> changedFiles = await finder.getChangedPubSpecs();
-
-      expect(changedFiles, equals(<String>['file1/pubspec.yaml']));
-    });
-
-    test('use correct base sha if not specified', () async {
-      mergeBaseResponse = 'shaqwiueroaaidf12312jnadf123nd';
-      gitDiffResponse = '''
-file1/pubspec.yaml
-file2/file2.cc
-''';
-
-      final GitVersionFinder finder = GitVersionFinder(gitDir, null);
-      await finder.getChangedFiles();
-      verify(gitDir.runCommand(
-          <String>['diff', '--name-only', mergeBaseResponse!, 'HEAD']));
-    });
-
-    test('use correct base sha if specified', () async {
-      const String customBaseSha = 'aklsjdcaskf12312';
-      gitDiffResponse = '''
-file1/pubspec.yaml
-file2/file2.cc
-''';
-      final GitVersionFinder finder = GitVersionFinder(gitDir, customBaseSha);
-      await finder.getChangedFiles();
-      verify(gitDir
-          .runCommand(<String>['diff', '--name-only', customBaseSha, 'HEAD']));
-    });
-  });
-
-  group('$PubVersionFinder', () {
-    test('Package does not exist.', () async {
-      final MockClient mockClient = MockClient((http.Request request) async {
-        return http.Response('', 404);
-      });
-      final PubVersionFinder finder = PubVersionFinder(httpClient: mockClient);
-      final PubVersionFinderResponse response =
-          await finder.getPackageVersion(package: 'some_package');
-
-      expect(response.versions, isEmpty);
-      expect(response.result, PubVersionFinderResult.noPackageFound);
-      expect(response.httpResponse.statusCode, 404);
-      expect(response.httpResponse.body, '');
-    });
-
-    test('HTTP error when getting versions from pub', () async {
-      final MockClient mockClient = MockClient((http.Request request) async {
-        return http.Response('', 400);
-      });
-      final PubVersionFinder finder = PubVersionFinder(httpClient: mockClient);
-      final PubVersionFinderResponse response =
-          await finder.getPackageVersion(package: 'some_package');
-
-      expect(response.versions, isEmpty);
-      expect(response.result, PubVersionFinderResult.fail);
-      expect(response.httpResponse.statusCode, 400);
-      expect(response.httpResponse.body, '');
-    });
-
-    test('Get a correct list of versions when http response is OK.', () async {
-      const Map<String, dynamic> httpResponse = <String, dynamic>{
-        'name': 'some_package',
-        'versions': <String>[
-          '0.0.1',
-          '0.0.2',
-          '0.0.2+2',
-          '0.1.1',
-          '0.0.1+1',
-          '0.1.0',
-          '0.2.0',
-          '0.1.0+1',
-          '0.0.2+1',
-          '2.0.0',
-          '1.2.0',
-          '1.0.0',
-        ],
-      };
-      final MockClient mockClient = MockClient((http.Request request) async {
-        return http.Response(json.encode(httpResponse), 200);
-      });
-      final PubVersionFinder finder = PubVersionFinder(httpClient: mockClient);
-      final PubVersionFinderResponse response =
-          await finder.getPackageVersion(package: 'some_package');
-
-      expect(response.versions, <Version>[
-        Version.parse('2.0.0'),
-        Version.parse('1.2.0'),
-        Version.parse('1.0.0'),
-        Version.parse('0.2.0'),
-        Version.parse('0.1.1'),
-        Version.parse('0.1.0+1'),
-        Version.parse('0.1.0'),
-        Version.parse('0.0.2+2'),
-        Version.parse('0.0.2+1'),
-        Version.parse('0.0.2'),
-        Version.parse('0.0.1+1'),
-        Version.parse('0.0.1'),
-      ]);
-      expect(response.result, PubVersionFinderResult.success);
-      expect(response.httpResponse.statusCode, 200);
-      expect(response.httpResponse.body, json.encode(httpResponse));
-    });
-  });
-
-  group('pluginSupportsPlatform', () {
-    test('no platforms', () async {
-      final Directory plugin = createFakePlugin('plugin', packagesDir);
-
-      expect(pluginSupportsPlatform('android', plugin), isFalse);
-      expect(pluginSupportsPlatform('ios', plugin), isFalse);
-      expect(pluginSupportsPlatform('linux', plugin), isFalse);
-      expect(pluginSupportsPlatform('macos', plugin), isFalse);
-      expect(pluginSupportsPlatform('web', plugin), isFalse);
-      expect(pluginSupportsPlatform('windows', plugin), isFalse);
-    });
-
-    test('all platforms', () async {
-      final Directory plugin = createFakePlugin(
-        'plugin',
-        packagesDir,
-        isAndroidPlugin: true,
-        isIosPlugin: true,
-        isLinuxPlugin: true,
-        isMacOsPlugin: true,
-        isWebPlugin: true,
-        isWindowsPlugin: true,
-      );
-
-      expect(pluginSupportsPlatform('android', plugin), isTrue);
-      expect(pluginSupportsPlatform('ios', plugin), isTrue);
-      expect(pluginSupportsPlatform('linux', plugin), isTrue);
-      expect(pluginSupportsPlatform('macos', plugin), isTrue);
-      expect(pluginSupportsPlatform('web', plugin), isTrue);
-      expect(pluginSupportsPlatform('windows', plugin), isTrue);
-    });
-
-    test('some platforms', () async {
-      final Directory plugin = createFakePlugin(
-        'plugin',
-        packagesDir,
-        isAndroidPlugin: true,
-        isIosPlugin: false,
-        isLinuxPlugin: true,
-        isMacOsPlugin: false,
-        isWebPlugin: true,
-        isWindowsPlugin: false,
-      );
-
-      expect(pluginSupportsPlatform('android', plugin), isTrue);
-      expect(pluginSupportsPlatform('ios', plugin), isFalse);
-      expect(pluginSupportsPlatform('linux', plugin), isTrue);
-      expect(pluginSupportsPlatform('macos', plugin), isFalse);
-      expect(pluginSupportsPlatform('web', plugin), isTrue);
-      expect(pluginSupportsPlatform('windows', plugin), isFalse);
-    });
-
-    test('inline plugins are only detected as inline', () async {
-      // createFakePlugin makes non-federated pubspec entries.
-      final Directory plugin = createFakePlugin(
-        'plugin',
-        packagesDir,
-        isAndroidPlugin: true,
-        isIosPlugin: true,
-        isLinuxPlugin: true,
-        isMacOsPlugin: true,
-        isWebPlugin: true,
-        isWindowsPlugin: true,
-      );
-
-      expect(
-          pluginSupportsPlatform('android', plugin,
-              requiredMode: PlatformSupport.inline),
-          isTrue);
-      expect(
-          pluginSupportsPlatform('android', plugin,
-              requiredMode: PlatformSupport.federated),
-          isFalse);
-      expect(
-          pluginSupportsPlatform('ios', plugin,
-              requiredMode: PlatformSupport.inline),
-          isTrue);
-      expect(
-          pluginSupportsPlatform('ios', plugin,
-              requiredMode: PlatformSupport.federated),
-          isFalse);
-      expect(
-          pluginSupportsPlatform('linux', plugin,
-              requiredMode: PlatformSupport.inline),
-          isTrue);
-      expect(
-          pluginSupportsPlatform('linux', plugin,
-              requiredMode: PlatformSupport.federated),
-          isFalse);
-      expect(
-          pluginSupportsPlatform('macos', plugin,
-              requiredMode: PlatformSupport.inline),
-          isTrue);
-      expect(
-          pluginSupportsPlatform('macos', plugin,
-              requiredMode: PlatformSupport.federated),
-          isFalse);
-      expect(
-          pluginSupportsPlatform('web', plugin,
-              requiredMode: PlatformSupport.inline),
-          isTrue);
-      expect(
-          pluginSupportsPlatform('web', plugin,
-              requiredMode: PlatformSupport.federated),
-          isFalse);
-      expect(
-          pluginSupportsPlatform('windows', plugin,
-              requiredMode: PlatformSupport.inline),
-          isTrue);
-      expect(
-          pluginSupportsPlatform('windows', plugin,
-              requiredMode: PlatformSupport.federated),
-          isFalse);
-    });
-
-    test('federated plugins are only detected as federated', () async {
-      const String pluginName = 'plugin';
-      final Directory plugin = createFakePlugin(
-        pluginName,
-        packagesDir,
-        isAndroidPlugin: true,
-        isIosPlugin: true,
-        isLinuxPlugin: true,
-        isMacOsPlugin: true,
-        isWebPlugin: true,
-        isWindowsPlugin: true,
-      );
-
-      createFakePubspec(
-        plugin,
-        name: pluginName,
-        androidSupport: PlatformSupport.federated,
-        iosSupport: PlatformSupport.federated,
-        linuxSupport: PlatformSupport.federated,
-        macosSupport: PlatformSupport.federated,
-        webSupport: PlatformSupport.federated,
-        windowsSupport: PlatformSupport.federated,
-      );
-
-      expect(
-          pluginSupportsPlatform('android', plugin,
-              requiredMode: PlatformSupport.federated),
-          isTrue);
-      expect(
-          pluginSupportsPlatform('android', plugin,
-              requiredMode: PlatformSupport.inline),
-          isFalse);
-      expect(
-          pluginSupportsPlatform('ios', plugin,
-              requiredMode: PlatformSupport.federated),
-          isTrue);
-      expect(
-          pluginSupportsPlatform('ios', plugin,
-              requiredMode: PlatformSupport.inline),
-          isFalse);
-      expect(
-          pluginSupportsPlatform('linux', plugin,
-              requiredMode: PlatformSupport.federated),
-          isTrue);
-      expect(
-          pluginSupportsPlatform('linux', plugin,
-              requiredMode: PlatformSupport.inline),
-          isFalse);
-      expect(
-          pluginSupportsPlatform('macos', plugin,
-              requiredMode: PlatformSupport.federated),
-          isTrue);
-      expect(
-          pluginSupportsPlatform('macos', plugin,
-              requiredMode: PlatformSupport.inline),
-          isFalse);
-      expect(
-          pluginSupportsPlatform('web', plugin,
-              requiredMode: PlatformSupport.federated),
-          isTrue);
-      expect(
-          pluginSupportsPlatform('web', plugin,
-              requiredMode: PlatformSupport.inline),
-          isFalse);
-      expect(
-          pluginSupportsPlatform('windows', plugin,
-              requiredMode: PlatformSupport.federated),
-          isTrue);
-      expect(
-          pluginSupportsPlatform('windows', plugin,
-              requiredMode: PlatformSupport.inline),
-          isFalse);
-    });
-  });
-}
-
-class SamplePluginCommand extends PluginCommand {
-  SamplePluginCommand(
-    this._plugins,
-    Directory packagesDir, {
-    ProcessRunner processRunner = const ProcessRunner(),
-    GitDir? gitDir,
-  }) : super(packagesDir, processRunner: processRunner, gitDir: gitDir);
-
-  final List<String> _plugins;
-
-  @override
-  final String name = 'sample';
-
-  @override
-  final String description = 'sample command';
-
-  @override
-  Future<void> run() async {
-    await for (final Directory package in getPlugins()) {
-      _plugins.add(package.path);
-    }
-  }
-}
-
-class MockProcessResult extends Mock implements ProcessResult {}
diff --git a/script/tool/test/drive_examples_command_test.dart b/script/tool/test/drive_examples_command_test.dart
index c9a8b9d..9c5bd18 100644
--- a/script/tool/test/drive_examples_command_test.dart
+++ b/script/tool/test/drive_examples_command_test.dart
@@ -5,7 +5,7 @@
 import 'package:args/command_runner.dart';
 import 'package:file/file.dart';
 import 'package:file/memory.dart';
-import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/common/core.dart';
 import 'package:flutter_plugin_tools/src/drive_examples_command.dart';
 import 'package:path/path.dart' as p;
 import 'package:platform/platform.dart';
diff --git a/script/tool/test/firebase_test_lab_test.dart b/script/tool/test/firebase_test_lab_test.dart
index aa8be17..0bc8f1e 100644
--- a/script/tool/test/firebase_test_lab_test.dart
+++ b/script/tool/test/firebase_test_lab_test.dart
@@ -7,7 +7,7 @@
 import 'package:args/command_runner.dart';
 import 'package:file/file.dart';
 import 'package:file/memory.dart';
-import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/common/core.dart';
 import 'package:flutter_plugin_tools/src/firebase_test_lab_command.dart';
 import 'package:test/test.dart';
 
diff --git a/script/tool/test/license_check_command_test.dart b/script/tool/test/license_check_command_test.dart
index a874d7d..dfe8d25 100644
--- a/script/tool/test/license_check_command_test.dart
+++ b/script/tool/test/license_check_command_test.dart
@@ -5,7 +5,7 @@
 import 'package:args/command_runner.dart';
 import 'package:file/file.dart';
 import 'package:file/memory.dart';
-import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/common/core.dart';
 import 'package:flutter_plugin_tools/src/license_check_command.dart';
 import 'package:test/test.dart';
 
diff --git a/script/tool/test/publish_check_command_test.dart b/script/tool/test/publish_check_command_test.dart
index e572256..c0ccd29 100644
--- a/script/tool/test/publish_check_command_test.dart
+++ b/script/tool/test/publish_check_command_test.dart
@@ -9,7 +9,7 @@
 import 'package:args/command_runner.dart';
 import 'package:file/file.dart';
 import 'package:file/memory.dart';
-import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/common/core.dart';
 import 'package:flutter_plugin_tools/src/publish_check_command.dart';
 import 'package:http/http.dart' as http;
 import 'package:http/testing.dart';
diff --git a/script/tool/test/publish_plugin_command_test.dart b/script/tool/test/publish_plugin_command_test.dart
index 1cb4245..ef682bf 100644
--- a/script/tool/test/publish_plugin_command_test.dart
+++ b/script/tool/test/publish_plugin_command_test.dart
@@ -9,7 +9,8 @@
 import 'package:args/command_runner.dart';
 import 'package:file/file.dart';
 import 'package:file/local.dart';
-import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/common/core.dart';
+import 'package:flutter_plugin_tools/src/common/process_runner.dart';
 import 'package:flutter_plugin_tools/src/publish_plugin_command.dart';
 import 'package:git/git.dart';
 import 'package:mockito/mockito.dart';
diff --git a/script/tool/test/pubspec_check_command_test.dart b/script/tool/test/pubspec_check_command_test.dart
index 576060d..f5fe6ae 100644
--- a/script/tool/test/pubspec_check_command_test.dart
+++ b/script/tool/test/pubspec_check_command_test.dart
@@ -5,7 +5,7 @@
 import 'package:args/command_runner.dart';
 import 'package:file/file.dart';
 import 'package:file/memory.dart';
-import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/common/core.dart';
 import 'package:flutter_plugin_tools/src/pubspec_check_command.dart';
 import 'package:test/test.dart';
 
diff --git a/script/tool/test/util.dart b/script/tool/test/util.dart
index c590d8a..79c46fc 100644
--- a/script/tool/test/util.dart
+++ b/script/tool/test/util.dart
@@ -9,7 +9,8 @@
 import 'package:args/command_runner.dart';
 import 'package:file/file.dart';
 import 'package:file/memory.dart';
-import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/common/plugin_utils.dart';
+import 'package:flutter_plugin_tools/src/common/process_runner.dart';
 import 'package:meta/meta.dart';
 import 'package:quiver/collection.dart';
 
diff --git a/script/tool/test/version_check_test.dart b/script/tool/test/version_check_test.dart
index 1199c27..a8e7e20 100644
--- a/script/tool/test/version_check_test.dart
+++ b/script/tool/test/version_check_test.dart
@@ -9,7 +9,7 @@
 import 'package:args/command_runner.dart';
 import 'package:file/file.dart';
 import 'package:file/memory.dart';
-import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/common/core.dart';
 import 'package:flutter_plugin_tools/src/version_check_command.dart';
 import 'package:http/http.dart' as http;
 import 'package:http/testing.dart';
@@ -17,7 +17,7 @@
 import 'package:pub_semver/pub_semver.dart';
 import 'package:test/test.dart';
 
-import 'common_test.mocks.dart';
+import 'common/plugin_command_test.mocks.dart';
 import 'util.dart';
 
 void testAllowedVersion(
diff --git a/script/tool/test/xctest_command_test.dart b/script/tool/test/xctest_command_test.dart
index 8ed8144..c0bd6b5 100644
--- a/script/tool/test/xctest_command_test.dart
+++ b/script/tool/test/xctest_command_test.dart
@@ -7,7 +7,8 @@
 import 'package:args/command_runner.dart';
 import 'package:file/file.dart';
 import 'package:file/memory.dart';
-import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/common/core.dart';
+import 'package:flutter_plugin_tools/src/common/plugin_utils.dart';
 import 'package:flutter_plugin_tools/src/xctest_command.dart';
 import 'package:test/test.dart';