Add Swift Package Manager as new opt-in feature for iOS and macOS (#146256)

This PR adds initial support for Swift Package Manager (SPM). Users must opt in. Only compatible with Xcode 15+.

Fixes flutter/flutter#146369.

## Included Features

This PR includes the following features:
* Enabling SPM via config 
`flutter config --enable-swift-package-manager`
* Disabling SPM via config (will disable for all projects) 
`flutter config --no-enable-swift-package-manager`
* Disabling SPM via pubspec.yaml (will disable for the specific project)
```
flutter:
  disable-swift-package-manager: true
```
* Migrating existing apps to add SPM integration if using a Flutter plugin with a Package.swift
  * Generates a Swift Package (named `FlutterGeneratedPluginSwiftPackage`) that handles Flutter SPM-compatible plugin dependencies. Generated package is added to the Xcode project.
* Error parsing of common errors that may occur due to using CocoaPods and Swift Package Manager together
* Tool will print warnings when using all Swift Package plugins and encourage you to remove CocoaPods

This PR also converts `integration_test` and `integration_test_macos` plugins to be both Swift Packages and CocoaPod Pods.

## How it Works
The Flutter CLI will generate a Swift Package called `FlutterGeneratedPluginSwiftPackage`, which will have local dependencies on all Swift Package compatible Flutter plugins.  

The `FlutterGeneratedPluginSwiftPackage` package will be added to the Xcode project via altering of the `project.pbxproj`. 

In addition, a "Pre-action" script will be added via altering of the `Runner.xcscheme`. This script will invoke the flutter tool to copy the Flutter/FlutterMacOS framework to the `BUILT_PRODUCTS_DIR` directory before the build starts. This is needed because plugins need to be linked to the Flutter framework and fortunately Swift Package Manager automatically uses `BUILT_PRODUCTS_DIR` as a framework search path.

CocoaPods will continue to run and be used to support non-Swift Package compatible Flutter plugins.

## Not Included Features

It does not include the following (will be added in future PRs):
* Create plugin template
* Create app template
* Add-to-App integration

Author: vashworth

dev/bots/analyze.dart

@@ -793,6 +793,9 @@ Future<void> _verifyNoMissingLicenseForExtension(
     if (contents.isEmpty) {
       continue; // let's not go down the /bin/true rabbit hole
     }
+    if (path.basename(file.path) == 'Package.swift') {
+      continue;
+    }
     if (!contents.startsWith(RegExp(header + licensePattern))) {
       errors.add(file.path);
     }

packages/flutter_tools/bin/macos_assemble.sh

@@ -144,11 +144,23 @@ BuildApp() {
   if [[ -n "$CODE_SIZE_DIRECTORY" ]]; then
     flutter_args+=("-dCodeSizeDirectory=${CODE_SIZE_DIRECTORY}")
   fi
-  flutter_args+=("${build_mode}_macos_bundle_flutter_assets")
+
+  # Run flutter assemble with the build mode specific target that was passed in.
+  # If no target was passed it, default to build mode specific
+  # macos_bundle_flutter_assets target.
+  if [[ -n "$1" ]]; then
+    flutter_args+=("${build_mode}$1")
+  else
+    flutter_args+=("${build_mode}_macos_bundle_flutter_assets")
+  fi
 
   RunCommand "${flutter_args[@]}"
 }
 
+PrepareFramework() {
+  BuildApp "_unpack_macos"
+}
+
 # Adds the App.framework as an embedded binary, the flutter_assets as
 # resources, and the native assets.
 EmbedFrameworks() {
@@ -192,5 +204,7 @@ else
       BuildApp ;;
     "embed")
       EmbedFrameworks ;;
+    "prepare")
+      PrepareFramework ;;
   esac
 fi

packages/flutter_tools/bin/podhelper.rb

@@ -302,7 +302,10 @@ def flutter_install_plugin_pods(application_path = nil, relative_symlink_dir, pl
   system('mkdir', '-p', symlink_plugins_dir)
 
   plugins_file = File.join(application_path, '..', '.flutter-plugins-dependencies')
-  plugin_pods = flutter_parse_plugins_file(plugins_file, platform)
+  dependencies_hash = flutter_parse_plugins_file(plugins_file)
+  plugin_pods = flutter_get_plugins_list(dependencies_hash, platform)
+  swift_package_manager_enabled = flutter_get_swift_package_manager_enabled(dependencies_hash)
+
   plugin_pods.each do |plugin_hash|
     plugin_name = plugin_hash['name']
     plugin_path = plugin_hash['path']
@@ -319,25 +322,43 @@ def flutter_install_plugin_pods(application_path = nil, relative_symlink_dir, pl
     # Keep pod path relative so it can be checked into Podfile.lock.
     relative = flutter_relative_path_from_podfile(symlink)
 
+    # If Swift Package Manager is enabled and the plugin has a Package.swift,
+    # skip from installing as a pod.
+    swift_package_exists = File.exists?(File.join(relative, platform_directory, plugin_name, "Package.swift"))
+    next if swift_package_manager_enabled && swift_package_exists
+
+    # If a plugin is Swift Package Manager compatible but not CocoaPods compatible, skip it.
+    # The tool will print an error about it.
+    next if swift_package_exists && !File.exists?(File.join(relative, platform_directory, plugin_name + ".podspec"))
+
     pod plugin_name, path: File.join(relative, platform_directory)
   end
 end
 
-# .flutter-plugins-dependencies format documented at
-# https://flutter.dev/go/plugins-list-migration
-def flutter_parse_plugins_file(file, platform)
+def flutter_parse_plugins_file(file)
   file_path = File.expand_path(file)
   return [] unless File.exist? file_path
 
   dependencies_file = File.read(file)
-  dependencies_hash = JSON.parse(dependencies_file)
+  JSON.parse(dependencies_file)
+end
 
+# .flutter-plugins-dependencies format documented at
+# https://flutter.dev/go/plugins-list-migration
+def flutter_get_plugins_list(dependencies_hash, platform)
   # dependencies_hash.dig('plugins', 'ios') not available until Ruby 2.3
+  return [] unless dependencies_hash.any?
   return [] unless dependencies_hash.has_key?('plugins')
   return [] unless dependencies_hash['plugins'].has_key?(platform)
   dependencies_hash['plugins'][platform] || []
 end
 
+def flutter_get_swift_package_manager_enabled(dependencies_hash)
+  return false unless dependencies_hash.any?
+  return false unless dependencies_hash.has_key?('swift_package_manager_enabled')
+  dependencies_hash['swift_package_manager_enabled'] == true
+end
+
 def flutter_relative_path_from_podfile(path)
   # defined_in_file is set by CocoaPods and is a Pathname to the Podfile.
   project_directory_pathname = defined_in_file.dirname

packages/flutter_tools/bin/xcode_backend.dart

@@ -49,6 +49,8 @@ class Context {
     switch (subCommand) {
       case 'build':
         buildApp();
+      case 'prepare':
+        prepare();
       case 'thin':
         // No-op, thinning is handled during the bundle asset assemble build target.
         break;
@@ -351,21 +353,67 @@ class Context {
     }
   }
 
+  void prepare() {
+    final bool verbose = (environment['VERBOSE_SCRIPT_LOGGING'] ?? '').isNotEmpty;
+    final String sourceRoot = environment['SOURCE_ROOT'] ?? '';
+    final String projectPath = environment['FLUTTER_APPLICATION_PATH'] ?? '$sourceRoot/..';
+
+    final String buildMode = parseFlutterBuildMode();
+
+    final List<String> flutterArgs = _generateFlutterArgsForAssemble(buildMode, verbose);
+
+    flutterArgs.add('${buildMode}_unpack_ios');
+
+    final ProcessResult result = runSync(
+      '${environmentEnsure('FLUTTER_ROOT')}/bin/flutter',
+      flutterArgs,
+      verbose: verbose,
+      allowFail: true,
+      workingDirectory: projectPath, // equivalent of RunCommand pushd "${project_path}"
+    );
+
+    if (result.exitCode != 0) {
+      echoError('Failed to copy Flutter framework.');
+      exitApp(-1);
+    }
+  }
+
   void buildApp() {
-    final bool verbose = environment['VERBOSE_SCRIPT_LOGGING'] != null && environment['VERBOSE_SCRIPT_LOGGING'] != '';
+    final bool verbose = (environment['VERBOSE_SCRIPT_LOGGING'] ?? '').isNotEmpty;
     final String sourceRoot = environment['SOURCE_ROOT'] ?? '';
-    String projectPath = '$sourceRoot/..';
-    if (environment['FLUTTER_APPLICATION_PATH'] != null) {
-      projectPath = environment['FLUTTER_APPLICATION_PATH']!;
+    final String projectPath = environment['FLUTTER_APPLICATION_PATH'] ?? '$sourceRoot/..';
+
+    final String buildMode = parseFlutterBuildMode();
+
+    final List<String> flutterArgs = _generateFlutterArgsForAssemble(buildMode, verbose);
+
+    flutterArgs.add('${buildMode}_ios_bundle_flutter_assets');
+
+    final ProcessResult result = runSync(
+      '${environmentEnsure('FLUTTER_ROOT')}/bin/flutter',
+      flutterArgs,
+      verbose: verbose,
+      allowFail: true,
+      workingDirectory: projectPath, // equivalent of RunCommand pushd "${project_path}"
+    );
+
+    if (result.exitCode != 0) {
+      echoError('Failed to package $projectPath.');
+      exitApp(-1);
     }
 
+    streamOutput('done');
+    streamOutput(' └─Compiling, linking and signing...');
+
+    echo('Project $projectPath built and packaged successfully.');
+  }
+
+  List<String> _generateFlutterArgsForAssemble(String buildMode, bool verbose) {
     String targetPath = 'lib/main.dart';
     if (environment['FLUTTER_TARGET'] != null) {
       targetPath = environment['FLUTTER_TARGET']!;
     }
 
-    final String buildMode = parseFlutterBuildMode();
-
     // Warn the user if not archiving (ACTION=install) in release mode.
     final String? action = environment['ACTION'];
     if (action == 'install' && buildMode != 'release') {
@@ -432,24 +480,6 @@ class Context {
       flutterArgs.add('-dCodeSizeDirectory=${environment['CODE_SIZE_DIRECTORY']}');
     }
 
-    flutterArgs.add('${buildMode}_ios_bundle_flutter_assets');
-
-    final ProcessResult result = runSync(
-      '${environmentEnsure('FLUTTER_ROOT')}/bin/flutter',
-      flutterArgs,
-      verbose: verbose,
-      allowFail: true,
-      workingDirectory: projectPath, // equivalent of RunCommand pushd "${project_path}"
-    );
-
-    if (result.exitCode != 0) {
-      echoError('Failed to package $projectPath.');
-      exitApp(-1);
-    }
-
-    streamOutput('done');
-    streamOutput(' └─Compiling, linking and signing...');
-
-    echo('Project $projectPath built and packaged successfully.');
+    return flutterArgs;
   }
 }

packages/flutter_tools/lib/src/commands/assemble.dart

@@ -41,6 +41,9 @@ List<Target> _kDefaultTargets = <Target>[
   const DebugMacOSBundleFlutterAssets(),
   const ProfileMacOSBundleFlutterAssets(),
   const ReleaseMacOSBundleFlutterAssets(),
+  const DebugUnpackMacOS(),
+  const ProfileUnpackMacOS(),
+  const ReleaseUnpackMacOS(),
   // Linux targets
   const DebugBundleLinuxAssets(TargetPlatform.linux_x64),
   const DebugBundleLinuxAssets(TargetPlatform.linux_arm64),
@@ -72,6 +75,9 @@ List<Target> _kDefaultTargets = <Target>[
   const DebugIosApplicationBundle(),
   const ProfileIosApplicationBundle(),
   const ReleaseIosApplicationBundle(),
+  const DebugUnpackIOS(),
+  const ProfileUnpackIOS(),
+  const ReleaseUnpackIOS(),
   // Windows targets
   const UnpackWindows(TargetPlatform.windows_x64),
   const UnpackWindows(TargetPlatform.windows_arm64),

packages/flutter_tools/lib/src/commands/build_ios.dart

@@ -23,6 +23,7 @@ import '../globals.dart' as globals;
 import '../ios/application_package.dart';
 import '../ios/mac.dart';
 import '../ios/plist_parser.dart';
+import '../project.dart';
 import '../reporting/reporting.dart';
 import '../runner/flutter_command.dart';
 import 'build.dart';
@@ -686,7 +687,15 @@ abstract class _BuildIOSSubCommand extends BuildSubCommand {
     xcodeBuildResult = result;
 
     if (!result.success) {
-      await diagnoseXcodeBuildFailure(result, globals.flutterUsage, globals.logger, globals.analytics);
+      await diagnoseXcodeBuildFailure(
+        result,
+        analytics: globals.analytics,
+        fileSystem: globals.fs,
+        flutterUsage: globals.flutterUsage,
+        logger: globals.logger,
+        platform: SupportedPlatform.ios,
+        project: app.project.parent,
+      );
       final String presentParticiple = xcodeBuildAction == XcodeBuildAction.build ? 'building' : 'archiving';
       throwToolExit('Encountered error while $presentParticiple for $logTarget.');
     }

packages/flutter_tools/lib/src/commands/build_ios_framework.dart

@@ -272,7 +272,12 @@ class BuildIOSFrameworkCommand extends BuildFrameworkCommand {
           buildInfo, modeDirectory, iPhoneBuildOutput, simulatorBuildOutput);
 
       // Build and copy plugins.
-      await processPodsIfNeeded(project.ios, getIosBuildDirectory(), buildInfo.mode);
+      await processPodsIfNeeded(
+        project.ios,
+        getIosBuildDirectory(),
+        buildInfo.mode,
+        forceCocoaPodsOnly: true,
+      );
       if (boolArg('plugins') && hasPlugins(project)) {
         await _producePlugins(buildInfo.mode, xcodeBuildConfiguration, iPhoneBuildOutput, simulatorBuildOutput, modeDirectory);
       }

packages/flutter_tools/lib/src/commands/build_macos_framework.dart

@@ -94,7 +94,12 @@ class BuildMacOSFrameworkCommand extends BuildFrameworkCommand {
       await _produceAppFramework(buildInfo, modeDirectory, buildOutput);
 
       // Build and copy plugins.
-      await processPodsIfNeeded(project.macos, getMacOSBuildDirectory(), buildInfo.mode);
+      await processPodsIfNeeded(
+        project.macos,
+        getMacOSBuildDirectory(),
+        buildInfo.mode,
+        forceCocoaPodsOnly: true,
+      );
       if (boolArg('plugins') && hasPlugins(project)) {
         await _producePlugins(xcodeBuildConfiguration, buildOutput, modeDirectory);
       }

packages/flutter_tools/lib/src/features.dart

@@ -51,6 +51,9 @@ abstract class FeatureFlags {
   /// Whether native assets compilation and bundling is enabled.
   bool get isPreviewDeviceEnabled => true;
 
+  /// Whether Swift Package Manager dependency management is enabled.
+  bool get isSwiftPackageManagerEnabled => false;
+
   /// Whether a particular feature is enabled for the current channel.
   ///
   /// Prefer using one of the specific getters above instead of this API.
@@ -70,6 +73,7 @@ const List<Feature> allFeatures = <Feature>[
   cliAnimation,
   nativeAssets,
   previewDevice,
+  swiftPackageManager,
 ];
 
 /// All current Flutter feature flags that can be configured.
@@ -175,6 +179,16 @@ const Feature previewDevice = Feature(
   ),
 );
 
+/// Enable Swift Package Mangaer as a darwin dependency manager.
+const Feature swiftPackageManager = Feature(
+  name: 'support for Swift Package Manager for iOS and macOS',
+  configSetting: 'enable-swift-package-manager',
+  environmentOverride: 'SWIFT_PACKAGE_MANAGER',
+  master: FeatureChannelSetting(
+    available: true,
+  ),
+);
+
 /// A [Feature] is a process for conditionally enabling tool features.
 ///
 /// All settings are optional, and if not provided will generally default to

packages/flutter_tools/lib/src/flutter_features.dart

@@ -58,6 +58,9 @@ class FlutterFeatureFlags implements FeatureFlags {
   @override
   bool get isPreviewDeviceEnabled => isEnabled(previewDevice);
 
+  @override
+  bool get isSwiftPackageManagerEnabled => isEnabled(swiftPackageManager);
+
   @override
   bool isEnabled(Feature feature) {
     final String currentChannel = _flutterVersion.channel;

packages/flutter_tools/lib/src/flutter_manifest.dart

@@ -136,6 +136,12 @@ class FlutterManifest {
     return _flutterDescriptor['uses-material-design'] as bool? ?? false;
   }
 
+  /// If true, does not use Swift Package Manager as a dependency manager.
+  /// CocoaPods will be used instead.
+  bool get disabledSwiftPackageManager {
+    return _flutterDescriptor['disable-swift-package-manager'] as bool? ?? false;
+  }
+
   /// True if this Flutter module should use AndroidX dependencies.
   ///
   /// If false the deprecated Android Support library will be used.
@@ -547,6 +553,10 @@ void _validateFlutter(YamlMap? yaml, List<String> errors) {
         break;
       case 'deferred-components':
         _validateDeferredComponents(kvp, errors);
+      case 'disable-swift-package-manager':
+        if (yamlValue is! bool) {
+          errors.add('Expected "$yamlKey" to be a bool, but got $yamlValue (${yamlValue.runtimeType}).');
+        }
       default:
         errors.add('Unexpected child "$yamlKey" found under "flutter".');
         break;