packages/flutter_tools/lib/src/plugins.dart

// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:async';

import 'package:mustache/mustache.dart' as mustache;
import 'package:xml/xml.dart' as xml;
import 'package:yaml/yaml.dart';

import 'android/gradle.dart';
import 'base/common.dart';
import 'base/file_system.dart';
import 'dart/package_map.dart';
import 'features.dart';
import 'globals.dart';
import 'macos/cocoapods.dart';
import 'platform_plugins.dart';
import 'project.dart';

void _renderTemplateToFile(String template, dynamic context, String filePath) {
  final String renderedTemplate =
     mustache.Template(template).renderString(context);
  final File file = fs.file(filePath);
  file.createSync(recursive: true);
  file.writeAsStringSync(renderedTemplate);
}

class Plugin {
  Plugin({
    this.name,
    this.path,
    this.platforms,
  });

  /// Parses [Plugin] specification from the provided pluginYaml.
  ///
  /// This currently supports two formats. Legacy and Multi-platform.
  /// Example of the deprecated Legacy format.
  /// flutter:
  ///  plugin:
  ///    androidPackage: io.flutter.plugins.sample
  ///    iosPrefix: FLT
  ///    pluginClass: SamplePlugin
  ///
  /// Example Multi-platform format.
  /// flutter:
  ///  plugin:
  ///    platforms:
  ///      android:
  ///        package: io.flutter.plugins.sample
  ///        pluginClass: SamplePlugin
  ///      ios:
  ///        pluginClass: SamplePlugin
  ///      linux:
  ///        pluginClass: SamplePlugin
  ///      macos:
  ///        pluginClass: SamplePlugin
  ///      windows:
  ///        pluginClass: SamplePlugin
  factory Plugin.fromYaml(String name, String path, dynamic pluginYaml) {
    final List<String> errors = validatePluginYaml(pluginYaml);
    if (errors.isNotEmpty) {
      throwToolExit('Invalid plugin specification.\n${errors.join('\n')}');
    }
    if (pluginYaml != null && pluginYaml['platforms'] != null) {
      return Plugin._fromMultiPlatformYaml(name, path, pluginYaml);
    }
    return Plugin._fromLegacyYaml(name, path, pluginYaml); // ignore: deprecated_member_use_from_same_package
  }

  factory Plugin._fromMultiPlatformYaml(String name, String path, dynamic pluginYaml) {
    assert (pluginYaml != null && pluginYaml['platforms'] != null,
            'Invalid multi-platform plugin specification.');
    final dynamic platformsYaml = pluginYaml['platforms'];

    assert (_validateMultiPlatformYaml(platformsYaml).isEmpty,
            'Invalid multi-platform plugin specification.');

    final Map<String, PluginPlatform> platforms = <String, PluginPlatform>{};

    if (platformsYaml[AndroidPlugin.kConfigKey] != null) {
      platforms[AndroidPlugin.kConfigKey] = AndroidPlugin.fromYaml(
        name,
        platformsYaml[AndroidPlugin.kConfigKey],
        path,
      );
    }

    if (platformsYaml[IOSPlugin.kConfigKey] != null) {
      platforms[IOSPlugin.kConfigKey] =
          IOSPlugin.fromYaml(name, platformsYaml[IOSPlugin.kConfigKey]);
    }

    if (platformsYaml[LinuxPlugin.kConfigKey] != null) {
      platforms[LinuxPlugin.kConfigKey] =
          LinuxPlugin.fromYaml(name, platformsYaml[LinuxPlugin.kConfigKey]);
    }

    if (platformsYaml[MacOSPlugin.kConfigKey] != null) {
      platforms[MacOSPlugin.kConfigKey] =
          MacOSPlugin.fromYaml(name, platformsYaml[MacOSPlugin.kConfigKey]);
    }

    if (platformsYaml[WebPlugin.kConfigKey] != null) {
      platforms[WebPlugin.kConfigKey] =
          WebPlugin.fromYaml(name, platformsYaml[WebPlugin.kConfigKey]);
    }

    if (platformsYaml[WindowsPlugin.kConfigKey] != null) {
      platforms[WindowsPlugin.kConfigKey] =
          WindowsPlugin.fromYaml(name, platformsYaml[WindowsPlugin.kConfigKey]);
    }

    return Plugin(
      name: name,
      path: path,
      platforms: platforms,
    );
  }

  @deprecated
  factory Plugin._fromLegacyYaml(String name, String path, dynamic pluginYaml) {
    final Map<String, PluginPlatform> platforms = <String, PluginPlatform>{};
    final String pluginClass = pluginYaml['pluginClass'];
    if (pluginYaml != null && pluginClass != null) {
      final String androidPackage = pluginYaml['androidPackage'];
      if (androidPackage != null) {
        platforms[AndroidPlugin.kConfigKey] = AndroidPlugin(
          name: name,
          package: pluginYaml['androidPackage'],
          pluginClass: pluginClass,
          pluginPath: path,
        );
      }

      final String iosPrefix = pluginYaml['iosPrefix'] ?? '';
      platforms[IOSPlugin.kConfigKey] =
          IOSPlugin(
            name: name,
            classPrefix: iosPrefix,
            pluginClass: pluginClass,
          );
    }
    return Plugin(
      name: name,
      path: path,
      platforms: platforms,
    );
  }

  static List<String> validatePluginYaml(YamlMap yaml) {
    if (yaml.containsKey('platforms')) {
      final int numKeys = yaml.keys.toSet().length;
      if (numKeys != 1) {
        return <String>[
          'Invalid plugin specification. There must be only one key: "platforms", found multiple: ${yaml.keys.join(',')}',
        ];
      } else {
        return _validateMultiPlatformYaml(yaml['platforms']);
      }
    } else {
      return _validateLegacyYaml(yaml);
    }
  }

  static List<String> _validateMultiPlatformYaml(YamlMap yaml) {
    final List<String> errors = <String>[];
    if (yaml.containsKey(AndroidPlugin.kConfigKey) &&
        !AndroidPlugin.validate(yaml[AndroidPlugin.kConfigKey])) {
      errors.add('Invalid "android" plugin specification.');
    }
    if (yaml.containsKey(IOSPlugin.kConfigKey) &&
        !IOSPlugin.validate(yaml[IOSPlugin.kConfigKey])) {
      errors.add('Invalid "ios" plugin specification.');
    }
    if (yaml.containsKey(LinuxPlugin.kConfigKey) &&
        !LinuxPlugin.validate(yaml[LinuxPlugin.kConfigKey])) {
      errors.add('Invalid "linux" plugin specification.');
    }
    if (yaml.containsKey(MacOSPlugin.kConfigKey) &&
        !MacOSPlugin.validate(yaml[MacOSPlugin.kConfigKey])) {
      errors.add('Invalid "macos" plugin specification.');
    }
    if (yaml.containsKey(WindowsPlugin.kConfigKey) &&
        !WindowsPlugin.validate(yaml[WindowsPlugin.kConfigKey])) {
      errors.add('Invalid "windows" plugin specification.');
    }
    return errors;
  }

  static List<String> _validateLegacyYaml(YamlMap yaml) {
    final List<String> errors = <String>[];
    if (yaml['androidPackage'] != null && yaml['androidPackage'] is! String) {
      errors.add('The "androidPackage" must either be null or a string.');
    }
    if (yaml['iosPrefix'] != null && yaml['iosPrefix'] is! String) {
      errors.add('The "iosPrefix" must either be null or a string.');
    }
    if (yaml['pluginClass'] != null && yaml['pluginClass'] is! String) {
      errors.add('The "pluginClass" must either be null or a string..');
    }
    return errors;
  }

  final String name;
  final String path;

  /// This is a mapping from platform config key to the plugin platform spec.
  final Map<String, PluginPlatform> platforms;
}

Plugin _pluginFromPubspec(String name, Uri packageRoot) {
  final String pubspecPath = fs.path.fromUri(packageRoot.resolve('pubspec.yaml'));
  if (!fs.isFileSync(pubspecPath)) {
    return null;
  }
  final dynamic pubspec = loadYaml(fs.file(pubspecPath).readAsStringSync());
  if (pubspec == null) {
    return null;
  }
  final dynamic flutterConfig = pubspec['flutter'];
  if (flutterConfig == null || !flutterConfig.containsKey('plugin')) {
    return null;
  }
  final String packageRootPath = fs.path.fromUri(packageRoot);
  printTrace('Found plugin $name at $packageRootPath');
  return Plugin.fromYaml(
    name,
    packageRootPath,
    flutterConfig['plugin'],
  );
}

List<Plugin> findPlugins(FlutterProject project) {
  final List<Plugin> plugins = <Plugin>[];
  Map<String, Uri> packages;
  try {
    final String packagesFile = fs.path.join(
      project.directory.path,
      PackageMap.globalPackagesPath,
    );
    packages = PackageMap(packagesFile).map;
  } on FormatException catch (e) {
    printTrace('Invalid .packages file: $e');
    return plugins;
  }
  packages.forEach((String name, Uri uri) {
    final Uri packageRoot = uri.resolve('..');
    final Plugin plugin = _pluginFromPubspec(name, packageRoot);
    if (plugin != null) {
      plugins.add(plugin);
    }
  });
  return plugins;
}

/// Returns true if .flutter-plugins has changed, otherwise returns false.
bool _writeFlutterPluginsList(FlutterProject project, List<Plugin> plugins) {
  final File pluginsFile = project.flutterPluginsFile;
  final String oldContents = _readFlutterPluginsList(project);
  final String pluginManifest =
      plugins.map<String>((Plugin p) => '${p.name}=${escapePath(p.path)}').join('\n');
  if (pluginManifest.isNotEmpty) {
    pluginsFile.writeAsStringSync('$pluginManifest\n', flush: true);
  } else {
    if (pluginsFile.existsSync()) {
      pluginsFile.deleteSync();
    }
  }
  final String newContents = _readFlutterPluginsList(project);
  return oldContents != newContents;
}

/// Returns the contents of the `.flutter-plugins` file in [project], or
/// null if that file does not exist.
String _readFlutterPluginsList(FlutterProject project) {
  return project.flutterPluginsFile.existsSync()
      ? project.flutterPluginsFile.readAsStringSync()
      : null;
}

const String _androidPluginRegistryTemplateOldEmbedding = '''package io.flutter.plugins;

import io.flutter.plugin.common.PluginRegistry;
{{#plugins}}
import {{package}}.{{class}};
{{/plugins}}

/**
 * Generated file. Do not edit.
 */
public final class GeneratedPluginRegistrant {
  public static void registerWith(PluginRegistry registry) {
    if (alreadyRegisteredWith(registry)) {
      return;
    }
{{#plugins}}
    {{class}}.registerWith(registry.registrarFor("{{package}}.{{class}}"));
{{/plugins}}
  }

  private static boolean alreadyRegisteredWith(PluginRegistry registry) {
    final String key = GeneratedPluginRegistrant.class.getCanonicalName();
    if (registry.hasPlugin(key)) {
      return true;
    }
    registry.registrarFor(key);
    return false;
  }
}
''';

const String _androidPluginRegistryTemplateNewEmbedding = '''package dev.flutter.plugins;

{{#androidX}}
import androidx.annotation.NonNull;
{{/androidX}}
{{^androidX}}
import android.support.annotation.NonNull;
{{/androidX}}
import io.flutter.embedding.engine.FlutterEngine;
{{#needsShim}}
import io.flutter.embedding.engine.plugins.shim.ShimPluginRegistry;
{{/needsShim}}

/**
 * Generated file. Do not edit.
 * This file is generated by the Flutter tool based on the
 * plugins that support the Android platform.
 */
public final class GeneratedPluginRegistrant {
  public static void registerWith(@NonNull FlutterEngine flutterEngine) {
{{#needsShim}}
    ShimPluginRegistry shimPluginRegistry = new ShimPluginRegistry(flutterEngine);
{{/needsShim}}
{{#plugins}}
  {{#usesEmbedding2}}
    flutterEngine.getPlugins().add(new {{package}}.{{class}}());
  {{/usesEmbedding2}}
  {{^usesEmbedding2}}
    {{package}}.{{class}}.registerWith(shimPluginRegistry.registrarFor("{{package}}.{{class}}"));
  {{/usesEmbedding2}}
{{/plugins}}
  }
}
''';

List<Map<String, dynamic>> _extractPlatformMaps(List<Plugin> plugins, String type) {
  final List<Map<String, dynamic>> pluginConfigs = <Map<String, dynamic>>[];
  for (Plugin p in plugins) {
    final PluginPlatform platformPlugin = p.platforms[type];
    if (platformPlugin != null) {
      pluginConfigs.add(platformPlugin.toMap());
    }
  }
  return pluginConfigs;
}

/// Returns the version of the Android embedding that the current
/// [project] is using.
String _getAndroidEmbeddingVersion(FlutterProject project) {
  if (!featureFlags.isNewAndroidEmbeddingEnabled) {
    return '1';
  }
  assert(project.android != null);
  final File androidManifest = project.android.appManifestFile;
  assert(androidManifest.existsSync());
  xml.XmlDocument document;
  try {
    document = xml.parse(androidManifest.readAsStringSync());
  } on xml.XmlParserException {
    throwToolExit('Error parsing ${project.android.appManifestFile} '
                  'Please ensure that the android manifest is a valid XML document and try again.');
  } on FileSystemException {
    throwToolExit('Error reading ${project.android.appManifestFile} even though it exists. '
                  'Please ensure that you have read permission to this file and try again.');
  }
  for (xml.XmlElement metaData in document.findAllElements('meta-data')) {
    final String name = metaData.getAttribute('android:name');
    if (name == 'flutterEmbedding') {
      return metaData.getAttribute('android:value');
    }
  }
  return '1';
}

Future<void> _writeAndroidPluginRegistrant(FlutterProject project, List<Plugin> plugins) async {
  final List<Map<String, dynamic>> androidPlugins =
    _extractPlatformMaps(plugins, AndroidPlugin.kConfigKey);

  final Map<String, dynamic> templateContext = <String, dynamic>{
    'plugins': androidPlugins,
    'androidX': isAppUsingAndroidX(project.android.hostAppGradleRoot),
  };
  final String javaSourcePath = fs.path.join(
    project.android.pluginRegistrantHost.path,
    'src',
    'main',
    'java',
  );

  String registryPath;
  String templateContent;

  final String appEmbeddingVersion = _getAndroidEmbeddingVersion(project);
  switch (appEmbeddingVersion) {
    case '2':
      templateContext['needsShim'] = false;
      // If a plugin is using an embedding version older than 2.0 and the app is using 2.0,
      // then add  shim for the old plugins.
      for (Map<String, dynamic> plugin in androidPlugins) {
        if (!plugin['usesEmbedding2']) {
          templateContext['needsShim'] = true;
          break;
        }
      }
      registryPath = fs.path.join(
        javaSourcePath,
        'dev',
        'flutter',
        'plugins',
        'GeneratedPluginRegistrant.java',
      );
      templateContent = _androidPluginRegistryTemplateNewEmbedding;
    break;
    case '1':
      registryPath = fs.path.join(
        javaSourcePath,
        'io',
        'flutter',
        'plugins',
        'GeneratedPluginRegistrant.java',
      );
      templateContent = _androidPluginRegistryTemplateOldEmbedding;
    break;
    default:
      throwToolExit('Unsupported Android embedding');
  }
  printTrace('Generating $registryPath');
  _renderTemplateToFile(
    templateContent,
    templateContext,
    registryPath,
  );
}

const String _objcPluginRegistryHeaderTemplate = '''//
//  Generated file. Do not edit.
//

#ifndef GeneratedPluginRegistrant_h
#define GeneratedPluginRegistrant_h

#import <{{framework}}/{{framework}}.h>

NS_ASSUME_NONNULL_BEGIN

@interface GeneratedPluginRegistrant : NSObject
+ (void)registerWithRegistry:(NSObject<FlutterPluginRegistry>*)registry;
@end

NS_ASSUME_NONNULL_END
#endif /* GeneratedPluginRegistrant_h */
''';

const String _objcPluginRegistryImplementationTemplate = '''//
//  Generated file. Do not edit.
//

#import "GeneratedPluginRegistrant.h"

{{#plugins}}
#if __has_include(<{{name}}/{{class}}.h>)
#import <{{name}}/{{class}}.h>
#else
@import {{name}};
#endif

{{/plugins}}
@implementation GeneratedPluginRegistrant

+ (void)registerWithRegistry:(NSObject<FlutterPluginRegistry>*)registry {
{{#plugins}}
  [{{prefix}}{{class}} registerWithRegistrar:[registry registrarForPlugin:@"{{prefix}}{{class}}"]];
{{/plugins}}
}

@end
''';

const String _swiftPluginRegistryTemplate = '''//
//  Generated file. Do not edit.
//

import {{framework}}
import Foundation

{{#plugins}}
import {{name}}
{{/plugins}}

func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
  {{#plugins}}
  {{class}}.register(with: registry.registrar(forPlugin: "{{class}}"))
{{/plugins}}
}
''';

const String _pluginRegistrantPodspecTemplate = '''
#
# Generated file, do not edit.
#

Pod::Spec.new do |s|
  s.name             = 'FlutterPluginRegistrant'
  s.version          = '0.0.1'
  s.summary          = 'Registers plugins with your flutter app'
  s.description      = <<-DESC
Depends on all your plugins, and provides a function to register them.
                       DESC
  s.homepage         = 'https://flutter.dev'
  s.license          = { :type => 'BSD' }
  s.author           = { 'Flutter Dev Team' => 'flutter-dev@googlegroups.com' }
  s.{{os}}.deployment_target = '{{deploymentTarget}}'
  s.source_files =  "Classes", "Classes/**/*.{h,m}"
  s.source           = { :path => '.' }
  s.public_header_files = './Classes/**/*.h'
  s.static_framework    = true
  s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES' }
  s.dependency '{{framework}}'
  {{#plugins}}
  s.dependency '{{name}}'
  {{/plugins}}
end
''';

const String _dartPluginRegistryTemplate = '''//
// Generated file. Do not edit.
//
import 'dart:ui';

{{#plugins}}
import 'package:{{name}}/{{file}}';
{{/plugins}}

import 'package:flutter_web_plugins/flutter_web_plugins.dart';

void registerPlugins(PluginRegistry registry) {
{{#plugins}}
  {{class}}.registerWith(registry.registrarFor({{class}}));
{{/plugins}}
  registry.registerMessageHandler();
}
''';

const String _cppPluginRegistryHeaderTemplate = '''//
//  Generated file. Do not edit.
//

#ifndef GENERATED_PLUGIN_REGISTRANT_
#define GENERATED_PLUGIN_REGISTRANT_

#include <flutter/plugin_registry.h>

// Registers Flutter plugins.
void RegisterPlugins(flutter::PluginRegistry* registry);

#endif  // GENERATED_PLUGIN_REGISTRANT_
''';

const String _cppPluginRegistryImplementationTemplate = '''//
//  Generated file. Do not edit.
//

#include "generated_plugin_registrant.h"

{{#plugins}}
#include <{{filename}}.h>
{{/plugins}}

void RegisterPlugins(flutter::PluginRegistry* registry) {
{{#plugins}}
  {{class}}RegisterWithRegistrar(
      registry->GetRegistrarForPlugin("{{class}}"));
{{/plugins}}
}
''';

Future<void> _writeIOSPluginRegistrant(FlutterProject project, List<Plugin> plugins) async {
  final List<Map<String, dynamic>> iosPlugins = _extractPlatformMaps(plugins, IOSPlugin.kConfigKey);
  final Map<String, dynamic> context = <String, dynamic>{
    'os': 'ios',
    'deploymentTarget': '8.0',
    'framework': 'Flutter',
    'plugins': iosPlugins,
  };
  final String registryDirectory = project.ios.pluginRegistrantHost.path;
  if (project.isModule) {
    final String registryClassesDirectory = fs.path.join(registryDirectory, 'Classes');
    _renderTemplateToFile(
      _pluginRegistrantPodspecTemplate,
      context,
      fs.path.join(registryDirectory, 'FlutterPluginRegistrant.podspec'),
    );
    _renderTemplateToFile(
      _objcPluginRegistryHeaderTemplate,
      context,
      fs.path.join(registryClassesDirectory, 'GeneratedPluginRegistrant.h'),
    );
    _renderTemplateToFile(
      _objcPluginRegistryImplementationTemplate,
      context,
      fs.path.join(registryClassesDirectory, 'GeneratedPluginRegistrant.m'),
    );
  } else {
    _renderTemplateToFile(
      _objcPluginRegistryHeaderTemplate,
      context,
      fs.path.join(registryDirectory, 'GeneratedPluginRegistrant.h'),
    );
    _renderTemplateToFile(
      _objcPluginRegistryImplementationTemplate,
      context,
      fs.path.join(registryDirectory, 'GeneratedPluginRegistrant.m'),
    );
  }
}

Future<void> _writeLinuxPluginRegistrant(FlutterProject project, List<Plugin> plugins) async {
  final List<Map<String, dynamic>> linuxPlugins = _extractPlatformMaps(plugins, LinuxPlugin.kConfigKey);
  final Map<String, dynamic> context = <String, dynamic>{
    'plugins': linuxPlugins,
  };
  await _writeCppPluginRegistrant(project.linux.managedDirectory, context);
}

Future<void> _writeMacOSPluginRegistrant(FlutterProject project, List<Plugin> plugins) async {
  final List<Map<String, dynamic>> macosPlugins = _extractPlatformMaps(plugins, MacOSPlugin.kConfigKey);
  final Map<String, dynamic> context = <String, dynamic>{
    'os': 'macos',
    'framework': 'FlutterMacOS',
    'plugins': macosPlugins,
  };
  final String registryDirectory = project.macos.managedDirectory.path;
  _renderTemplateToFile(
    _swiftPluginRegistryTemplate,
    context,
    fs.path.join(registryDirectory, 'GeneratedPluginRegistrant.swift'),
  );
}

Future<void> _writeWindowsPluginRegistrant(FlutterProject project, List<Plugin> plugins) async {
  final List<Map<String, dynamic>> windowsPlugins = _extractPlatformMaps(plugins, WindowsPlugin.kConfigKey);
  final Map<String, dynamic> context = <String, dynamic>{
    'plugins': windowsPlugins,
  };
  await _writeCppPluginRegistrant(project.windows.managedDirectory, context);
}

Future<void> _writeCppPluginRegistrant(Directory destination, Map<String, dynamic> templateContext) async {
  final String registryDirectory = destination.path;
  _renderTemplateToFile(
    _cppPluginRegistryHeaderTemplate,
    templateContext,
    fs.path.join(registryDirectory, 'generated_plugin_registrant.h'),
  );
  _renderTemplateToFile(
    _cppPluginRegistryImplementationTemplate,
    templateContext,
    fs.path.join(registryDirectory, 'generated_plugin_registrant.cc'),
  );
}

Future<void> _writeWebPluginRegistrant(FlutterProject project, List<Plugin> plugins) async {
  final List<Map<String, dynamic>> webPlugins = _extractPlatformMaps(plugins, WebPlugin.kConfigKey);
  final Map<String, dynamic> context = <String, dynamic>{
    'plugins': webPlugins,
  };
  final String registryDirectory = project.web.libDirectory.path;
  final String filePath = fs.path.join(registryDirectory, 'generated_plugin_registrant.dart');
  if (webPlugins.isEmpty) {
    final File file = fs.file(filePath);
    if (file.existsSync()) {
      file.deleteSync();
    }
  } else {
    _renderTemplateToFile(
      _dartPluginRegistryTemplate,
      context,
      filePath,
    );
  }
}

/// Rewrites the `.flutter-plugins` file of [project] based on the plugin
/// dependencies declared in `pubspec.yaml`.
///
/// If `checkProjects` is true, then plugins are only injected into directories
/// which already exist.
///
/// Assumes `pub get` has been executed since last change to `pubspec.yaml`.
void refreshPluginsList(FlutterProject project, {bool checkProjects = false}) {
  final List<Plugin> plugins = findPlugins(project);
  final bool changed = _writeFlutterPluginsList(project, plugins);
  if (changed) {
    if (!checkProjects || project.ios.existsSync()) {
      cocoaPods.invalidatePodInstallOutput(project.ios);
    }
    // TODO(stuartmorgan): Potentially add checkProjects once a decision has
    // made about how to handle macOS in existing projects.
    if (project.macos.existsSync()) {
      cocoaPods.invalidatePodInstallOutput(project.macos);
    }
  }
}

/// Injects plugins found in `pubspec.yaml` into the platform-specific projects.
///
/// If `checkProjects` is true, then plugins are only injected into directories
/// which already exist.
///
/// Assumes [refreshPluginsList] has been called since last change to `pubspec.yaml`.
Future<void> injectPlugins(FlutterProject project, {bool checkProjects = false}) async {
  final List<Plugin> plugins = findPlugins(project);
  if ((checkProjects && project.android.existsSync()) || !checkProjects) {
    await _writeAndroidPluginRegistrant(project, plugins);
  }
  if ((checkProjects && project.ios.existsSync()) || !checkProjects) {
    await _writeIOSPluginRegistrant(project, plugins);
  }
  // TODO(stuartmorgan): Revisit the conditions here once the plans for handling
  // desktop in existing projects are in place. For now, ignore checkProjects
  // on desktop and always treat it as true.
  if (featureFlags.isLinuxEnabled && project.linux.existsSync()) {
    await _writeLinuxPluginRegistrant(project, plugins);
  }
  if (featureFlags.isMacOSEnabled && project.macos.existsSync()) {
    await _writeMacOSPluginRegistrant(project, plugins);
  }
  if (featureFlags.isWindowsEnabled && project.windows.existsSync()) {
    await _writeWindowsPluginRegistrant(project, plugins);
  }
  for (final XcodeBasedProject subproject in <XcodeBasedProject>[project.ios, project.macos]) {
    if (!project.isModule && (!checkProjects || subproject.existsSync())) {
      final CocoaPods cocoaPods = CocoaPods();
      if (plugins.isNotEmpty) {
        await cocoaPods.setupPodfile(subproject);
      }
      /// The user may have a custom maintained Podfile that they're running `pod install`
      /// on themselves.
      else if (subproject.podfile.existsSync() && subproject.podfileLock.existsSync()) {
        cocoaPods.addPodsDependencyToFlutterXcconfig(subproject);
      }
    }
  }
  if (featureFlags.isWebEnabled && project.web.existsSync()) {
    await _writeWebPluginRegistrant(project, plugins);
  }
}

/// Returns whether the specified Flutter [project] has any plugin dependencies.
///
/// Assumes [refreshPluginsList] has been called since last change to `pubspec.yaml`.
bool hasPlugins(FlutterProject project) {
  return _readFlutterPluginsList(project) != null;
}