Symlink SwiftPM plugins in the same directory (#168932)

This PR symlinks SwiftPM plugins in the same directory so that they're
relative to each other and the `FlutterGeneratedPluginSwiftPackage`.

This allows plugins to depend on each other via relative paths.

For example,

> Flutter/ephemeral/Packages/.packages/plugin_a --> symlink -->
/local/path/to/plugin_a
> Flutter/ephemeral/Packages/.packages/plugin_b --> symlink -->
/path/to/.pub-cache/plugin_b

Then in plugin_b's Package.swift, you can do the following to add a
dependency on plugin_a:
```swift
dependencies: [
  .package(name: "plugin_a", path: "../plugin_a"),
],
```

Addresses https://github.com/flutter/flutter/issues/166528 and
incremental change toward
https://github.com/flutter/flutter/issues/166489.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

packages/flutter_tools/lib/src/macos/swift_package_manager.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import '../base/common.dart';
+import '../base/error_handling_io.dart';
 import '../base/file_system.dart';
 import '../base/template.dart';
 import '../base/version.dart';
@@ -54,10 +55,19 @@ class SwiftPackageManager {
   ) async {
     _validatePlatform(platform);
 
+    final Directory symlinkDirectory = project.relativeSwiftPackagesDirectory;
+    ErrorHandlingFileSystem.deleteIfExists(symlinkDirectory, recursive: true);
+    symlinkDirectory.createSync(recursive: true);
+
     final (
       List<SwiftPackagePackageDependency> packageDependencies,
       List<SwiftPackageTargetDependency> targetDependencies,
-    ) = _dependenciesForPlugins(plugins, platform);
+    ) = _dependenciesForPlugins(
+      plugins: plugins,
+      platform: platform,
+      symlinkDirectory: symlinkDirectory,
+      pathRelativeTo: project.flutterPluginSwiftPackageDirectory.path,
+    );
 
     // If there aren't any Swift Package plugins and the project hasn't been
     // migrated yet, don't generate a Swift package or migrate the app since
@@ -100,10 +110,13 @@ class SwiftPackageManager {
     pluginsPackage.createSwiftPackage();
   }
 
-  (List<SwiftPackagePackageDependency>, List<SwiftPackageTargetDependency>) _dependenciesForPlugins(
+  (List<SwiftPackagePackageDependency>, List<SwiftPackageTargetDependency>)
-    List<Plugin> plugins,
+  _dependenciesForPlugins({
-    SupportedPlatform platform,
+    required List<Plugin> plugins,
-  ) {
+    required SupportedPlatform platform,
+    required Directory symlinkDirectory,
+    required String pathRelativeTo,
+  }) {
     final List<SwiftPackagePackageDependency> packageDependencies =
         <SwiftPackagePackageDependency>[];
     final List<SwiftPackageTargetDependency> targetDependencies = <SwiftPackageTargetDependency>[];
@@ -113,18 +126,21 @@ class SwiftPackageManager {
         _fileSystem,
         platform.name,
       );
+      String? packagePath = plugin.pluginSwiftPackagePath(_fileSystem, platform.name);
       if (plugin.platforms[platform.name] == null ||
           pluginSwiftPackageManifestPath == null ||
+          packagePath == null ||
           !_fileSystem.file(pluginSwiftPackageManifestPath).existsSync()) {
         continue;
       }
 
-      packageDependencies.add(
+      final Link pluginSymlink = symlinkDirectory.childLink(plugin.name);
-        SwiftPackagePackageDependency(
+      ErrorHandlingFileSystem.deleteIfExists(pluginSymlink);
-          name: plugin.name,
+      pluginSymlink.createSync(packagePath);
-          path: _fileSystem.file(pluginSwiftPackageManifestPath).parent.path,
+      packagePath = pluginSymlink.path;
-        ),
+      packagePath = _fileSystem.path.relative(packagePath, from: pathRelativeTo);
-      );
+
+      packageDependencies.add(SwiftPackagePackageDependency(name: plugin.name, path: packagePath));
 
       // The target dependency product name is hyphen separated because it's
       // the dependency's library name, which Swift Package Manager will

packages/flutter_tools/lib/src/plugins.dart

@@ -438,14 +438,29 @@ class Plugin {
   /// Dev dependencies are intended to be stripped out in release builds.
   final bool isDevDependency;
 
-  /// Expected path to the plugin's Package.swift. Returns null if the plugin
+  /// Expected path to the plugin's swift package, which contains the Package.swift.
-  /// does not support the [platform] or the [platform] is not iOS or macOS.
+  ///
-  String? pluginSwiftPackageManifestPath(FileSystem fileSystem, String platform) {
+  /// This path should be `/path/to/[package_name]/[platform]/[package_name]`
+  /// (e.g. `/path/to/my_plugin/ios/my_plugin`).
+  ///
+  /// Returns null if the plugin does not support the [platform] or the
+  /// [platform] is not iOS or macOS.
+  String? pluginSwiftPackagePath(FileSystem fileSystem, String platform) {
     final String? platformDirectoryName = _darwinPluginDirectoryName(platform);
     if (platformDirectoryName == null) {
       return null;
     }
-    return fileSystem.path.join(path, platformDirectoryName, name, 'Package.swift');
+    return fileSystem.path.join(path, platformDirectoryName, name);
+  }
+
+  /// Expected path to the plugin's Package.swift. Returns null if the plugin
+  /// does not support the [platform] or the [platform] is not iOS or macOS.
+  String? pluginSwiftPackageManifestPath(FileSystem fileSystem, String platform) {
+    final String? packagePath = pluginSwiftPackagePath(fileSystem, platform);
+    if (packagePath == null) {
+      return null;
+    }
+    return fileSystem.path.join(packagePath, 'Package.swift');
   }
 
   /// Expected path to the plugin's podspec. Returns null if the plugin does

packages/flutter_tools/lib/src/xcode_project.dart

@@ -139,13 +139,20 @@ abstract class XcodeBasedProject extends FlutterProjectPlatform {
   /// checked in should live here.
   Directory get ephemeralDirectory => managedDirectory.childDirectory('ephemeral');
 
-  /// The Flutter generated directory for the Swift Package handling plugin
+  /// The Flutter generated directory for generated Swift packages.
-  /// dependencies.
+  Directory get flutterSwiftPackagesDirectory => ephemeralDirectory.childDirectory('Packages');
-  Directory get flutterPluginSwiftPackageDirectory => ephemeralDirectory
-      .childDirectory('Packages')
-      .childDirectory(kFlutterGeneratedPluginSwiftPackageName);
 
-  /// The Flutter generated Swift Package manifest (Package.swift) for plugin
+  /// Flutter plugins that support SwiftPM will be symlinked in this directory to keep all
+  /// Swift packages relative to each other.
+  Directory get relativeSwiftPackagesDirectory =>
+      flutterSwiftPackagesDirectory.childDirectory('.packages');
+
+  /// The Flutter generated directory for the Swift package handling plugin
+  /// dependencies.
+  Directory get flutterPluginSwiftPackageDirectory =>
+      flutterSwiftPackagesDirectory.childDirectory(kFlutterGeneratedPluginSwiftPackageName);
+
+  /// The Flutter generated Swift package manifest (Package.swift) for plugin
   /// dependencies.
   File get flutterPluginSwiftPackageManifest =>
       flutterPluginSwiftPackageDirectory.childFile('Package.swift');

packages/flutter_tools/test/general.shard/macos/cocoapod_utils_test.dart

@@ -506,12 +506,20 @@ class FakeMacOSProject extends Fake implements MacOSProject {
       hostAppRoot.childDirectory('Runner.xcodeproj').childFile('project.pbxproj');
 
   @override
-  File get flutterPluginSwiftPackageManifest => hostAppRoot
+  Directory get flutterSwiftPackagesDirectory =>
-      .childDirectory('Flutter')
+      hostAppRoot.childDirectory('Flutter').childDirectory('ephemeral').childDirectory('Packages');
-      .childDirectory('ephemeral')
+
-      .childDirectory('Packages')
+  @override
-      .childDirectory('FlutterGeneratedPluginSwiftPackage')
+  Directory get relativeSwiftPackagesDirectory =>
-      .childFile('Package.swift');
+      flutterSwiftPackagesDirectory.childDirectory('.packages');
+
+  @override
+  Directory get flutterPluginSwiftPackageDirectory =>
+      flutterSwiftPackagesDirectory.childDirectory('FlutterGeneratedPluginSwiftPackage');
+
+  @override
+  File get flutterPluginSwiftPackageManifest =>
+      flutterPluginSwiftPackageDirectory.childFile('Package.swift');
 
   @override
   bool usesSwiftPackageManager = false;
@@ -547,12 +555,20 @@ class FakeIosProject extends Fake implements IosProject {
       hostAppRoot.childDirectory('Runner.xcodeproj').childFile('project.pbxproj');
 
   @override
-  File get flutterPluginSwiftPackageManifest => hostAppRoot
+  Directory get flutterSwiftPackagesDirectory =>
-      .childDirectory('Flutter')
+      hostAppRoot.childDirectory('Flutter').childDirectory('ephemeral').childDirectory('Packages');
-      .childDirectory('ephemeral')
+
-      .childDirectory('Packages')
+  @override
-      .childDirectory('FlutterGeneratedPluginSwiftPackage')
+  Directory get relativeSwiftPackagesDirectory =>
-      .childFile('Package.swift');
+      flutterSwiftPackagesDirectory.childDirectory('.packages');
+
+  @override
+  Directory get flutterPluginSwiftPackageDirectory =>
+      flutterSwiftPackagesDirectory.childDirectory('FlutterGeneratedPluginSwiftPackage');
+
+  @override
+  File get flutterPluginSwiftPackageManifest =>
+      flutterPluginSwiftPackageDirectory.childFile('Package.swift');
 
   @override
   bool usesSwiftPackageManager = false;

packages/flutter_tools/test/general.shard/macos/swift_package_manager_test.dart

@@ -4,6 +4,7 @@
 
 import 'package:file/file.dart';
 import 'package:file/memory.dart';
+import 'package:file_testing/file_testing.dart';
 import 'package:flutter_tools/src/isolated/mustache_template.dart';
 import 'package:flutter_tools/src/macos/swift_package_manager.dart';
 import 'package:flutter_tools/src/platform_plugins.dart';
@@ -118,13 +119,15 @@ $_doubleIndent
               fileSystem: fs,
             );
 
-            final File validPlugin1Manifest = fs.file(
+            final Directory validPlugin1Directory = fs.directory(
-              '/local/path/to/plugins/valid_plugin_1/Package.swift',
+              '/local/path/to/plugins/valid_plugin_1',
-            )..createSync(recursive: true);
+            );
+            validPlugin1Directory.childFile('Package.swift').createSync(recursive: true);
+
             final FakePlugin validPlugin1 = FakePlugin(
               name: 'valid_plugin_1',
               platforms: <String, PluginPlatform>{platform.name: FakePluginPlatform()},
-              pluginSwiftPackageManifestPath: validPlugin1Manifest.path,
+              pluginSwiftPackagePath: validPlugin1Directory.path,
             );
             final SwiftPackageManager spm = SwiftPackageManager(
               fileSystem: fs,
@@ -135,6 +138,11 @@ $_doubleIndent
             final String supportedPlatform =
                 platform == SupportedPlatform.ios ? '.iOS("13.0")' : '.macOS("10.15")';
             expect(project.flutterPluginSwiftPackageManifest.existsSync(), isTrue);
+            expect(project.relativeSwiftPackagesDirectory.childLink('valid_plugin_1'), exists);
+            expect(
+              project.relativeSwiftPackagesDirectory.childLink('valid_plugin_1').targetSync(),
+              validPlugin1Directory.path,
+            );
             expect(project.flutterPluginSwiftPackageManifest.readAsStringSync(), '''
 // swift-tools-version: 5.9
 // The swift-tools-version declares the minimum version of Swift required to build this package.
@@ -153,7 +161,7 @@ let package = Package(
         .library(name: "FlutterGeneratedPluginSwiftPackage", type: .static, targets: ["FlutterGeneratedPluginSwiftPackage"])
     ],
     dependencies: [
-        .package(name: "valid_plugin_1", path: "/local/path/to/plugins/valid_plugin_1")
+        .package(name: "valid_plugin_1", path: "../.packages/valid_plugin_1")
     ],
     targets: [
         .target(
@@ -176,34 +184,38 @@ let package = Package(
             final FakePlugin nonPlatformCompatiblePlugin = FakePlugin(
               name: 'invalid_plugin_due_to_incompatible_platform',
               platforms: <String, PluginPlatform>{},
-              pluginSwiftPackageManifestPath: '/some/path',
+              pluginSwiftPackagePath: '/some/path',
             );
             final FakePlugin pluginSwiftPackageManifestIsNull = FakePlugin(
               name: 'invalid_plugin_due_to_null_plugin_swift_package_path',
               platforms: <String, PluginPlatform>{platform.name: FakePluginPlatform()},
-              pluginSwiftPackageManifestPath: null,
+              pluginSwiftPackagePath: null,
             );
             final FakePlugin pluginSwiftPackageManifestNotExists = FakePlugin(
               name: 'invalid_plugin_due_to_plugin_swift_package_path_does_not_exist',
               platforms: <String, PluginPlatform>{platform.name: FakePluginPlatform()},
-              pluginSwiftPackageManifestPath: '/some/path',
+              pluginSwiftPackagePath: '/some/path',
             );
 
-            final File validPlugin1Manifest = fs.file(
+            final Directory validPlugin1Directory = fs.directory(
-              '/local/path/to/plugins/valid_plugin_1/Package.swift',
+              '/local/path/to/plugins/valid_plugin_1',
-            )..createSync(recursive: true);
+            );
+            validPlugin1Directory.childFile('Package.swift').createSync(recursive: true);
             final FakePlugin validPlugin1 = FakePlugin(
               name: 'valid_plugin_1',
               platforms: <String, PluginPlatform>{platform.name: FakePluginPlatform()},
-              pluginSwiftPackageManifestPath: validPlugin1Manifest.path,
+              pluginSwiftPackagePath: validPlugin1Directory.path,
             );
-            final File validPlugin2Manifest = fs.file(
+
-              '/.pub-cache/plugins/valid_plugin_2/Package.swift',
+            final Directory validPlugin2Directory = fs.directory(
-            )..createSync(recursive: true);
+              '/.pub-cache/plugins/valid_plugin_2',
+            );
+            validPlugin2Directory.childFile('Package.swift').createSync(recursive: true);
+
             final FakePlugin validPlugin2 = FakePlugin(
               name: 'valid_plugin_2',
               platforms: <String, PluginPlatform>{platform.name: FakePluginPlatform()},
-              pluginSwiftPackageManifestPath: validPlugin2Manifest.path,
+              pluginSwiftPackagePath: validPlugin2Directory.path,
             );
 
             final SwiftPackageManager spm = SwiftPackageManager(
@@ -225,6 +237,16 @@ let package = Package(
             final String supportedPlatform =
                 platform == SupportedPlatform.ios ? '.iOS("13.0")' : '.macOS("10.15")';
             expect(project.flutterPluginSwiftPackageManifest.existsSync(), isTrue);
+            expect(project.relativeSwiftPackagesDirectory.childLink('valid_plugin_1'), exists);
+            expect(
+              project.relativeSwiftPackagesDirectory.childLink('valid_plugin_1').targetSync(),
+              validPlugin1Directory.path,
+            );
+            expect(project.relativeSwiftPackagesDirectory.childLink('valid_plugin_2'), exists);
+            expect(
+              project.relativeSwiftPackagesDirectory.childLink('valid_plugin_2').targetSync(),
+              validPlugin2Directory.path,
+            );
             expect(project.flutterPluginSwiftPackageManifest.readAsStringSync(), '''
 // swift-tools-version: 5.9
 // The swift-tools-version declares the minimum version of Swift required to build this package.
@@ -243,8 +265,8 @@ let package = Package(
         .library(name: "FlutterGeneratedPluginSwiftPackage", type: .static, targets: ["FlutterGeneratedPluginSwiftPackage"])
     ],
     dependencies: [
-        .package(name: "valid_plugin_1", path: "/local/path/to/plugins/valid_plugin_1"),
+        .package(name: "valid_plugin_1", path: "../.packages/valid_plugin_1"),
-        .package(name: "valid_plugin_2", path: "/.pub-cache/plugins/valid_plugin_2")
+        .package(name: "valid_plugin_2", path: "../.packages/valid_plugin_2")
     ],
     targets: [
         .target(
@@ -373,11 +395,16 @@ class FakeXcodeProject extends Fake implements IosProject {
   String hostAppProjectName = 'Runner';
 
   @override
-  Directory get flutterPluginSwiftPackageDirectory => hostAppRoot
+  Directory get flutterSwiftPackagesDirectory =>
-      .childDirectory('Flutter')
+      hostAppRoot.childDirectory('Flutter').childDirectory('ephemeral').childDirectory('Packages');
-      .childDirectory('ephemeral')
+
-      .childDirectory('Packages')
+  @override
-      .childDirectory('FlutterGeneratedPluginSwiftPackage');
+  Directory get relativeSwiftPackagesDirectory =>
+      flutterSwiftPackagesDirectory.childDirectory('.packages');
+
+  @override
+  Directory get flutterPluginSwiftPackageDirectory =>
+      flutterSwiftPackagesDirectory.childDirectory('FlutterGeneratedPluginSwiftPackage');
 
   @override
   File get flutterPluginSwiftPackageManifest =>
@@ -391,13 +418,10 @@ class FakeXcodeProject extends Fake implements IosProject {
 }
 
 class FakePlugin extends Fake implements Plugin {
-  FakePlugin({
+  FakePlugin({required this.name, required this.platforms, required String? pluginSwiftPackagePath})
-    required this.name,
+    : _pluginSwiftPackagePath = pluginSwiftPackagePath;
-    required this.platforms,
-    required String? pluginSwiftPackageManifestPath,
-  }) : _pluginSwiftPackageManifestPath = pluginSwiftPackageManifestPath;
 
-  final String? _pluginSwiftPackageManifestPath;
+  final String? _pluginSwiftPackagePath;
 
   @override
   final String name;
@@ -405,9 +429,17 @@ class FakePlugin extends Fake implements Plugin {
   @override
   final Map<String, PluginPlatform> platforms;
 
+  @override
+  String? pluginSwiftPackagePath(FileSystem fileSystem, String platform) {
+    return _pluginSwiftPackagePath;
+  }
+
   @override
   String? pluginSwiftPackageManifestPath(FileSystem fileSystem, String platform) {
-    return _pluginSwiftPackageManifestPath;
+    if (_pluginSwiftPackagePath == null) {
+      return null;
+    }
+    return '$_pluginSwiftPackagePath/Package.swift';
   }
 }
 

packages/flutter_tools/test/general.shard/plugins_test.dart

@@ -2153,7 +2153,7 @@ flutter:
     });
 
     group('Plugin files', () {
-      testWithoutContext('pluginSwiftPackageManifestPath for iOS and macOS plugins', () async {
+      testWithoutContext('for SwiftPM and podspec paths for iOS and macOS plugins', () async {
         final MemoryFileSystem fs = MemoryFileSystem.test();
         final Plugin plugin = Plugin(
           name: 'test',
@@ -2168,7 +2168,11 @@ flutter:
           isDirectDependency: true,
           isDevDependency: false,
         );
-
+        expect(plugin.pluginSwiftPackagePath(fs, IOSPlugin.kConfigKey), '/path/to/test/ios/test');
+        expect(
+          plugin.pluginSwiftPackagePath(fs, MacOSPlugin.kConfigKey),
+          '/path/to/test/macos/test',
+        );
         expect(
           plugin.pluginSwiftPackageManifestPath(fs, IOSPlugin.kConfigKey),
           '/path/to/test/ios/test/Package.swift',
@@ -2177,74 +2181,6 @@ flutter:
           plugin.pluginSwiftPackageManifestPath(fs, MacOSPlugin.kConfigKey),
           '/path/to/test/macos/test/Package.swift',
         );
-      });
-
-      testWithoutContext('pluginSwiftPackageManifestPath for darwin plugins', () async {
-        final MemoryFileSystem fs = MemoryFileSystem.test();
-        final Plugin plugin = Plugin(
-          name: 'test',
-          path: '/path/to/test/',
-          defaultPackagePlatforms: const <String, String>{},
-          pluginDartClassPlatforms: const <String, DartPluginClassAndFilePair>{},
-          platforms: const <String, PluginPlatform>{
-            IOSPlugin.kConfigKey: IOSPlugin(
-              name: 'test',
-              classPrefix: '',
-              sharedDarwinSource: true,
-            ),
-            MacOSPlugin.kConfigKey: MacOSPlugin(name: 'test', sharedDarwinSource: true),
-          },
-          dependencies: <String>[],
-          isDirectDependency: true,
-          isDevDependency: false,
-        );
-
-        expect(
-          plugin.pluginSwiftPackageManifestPath(fs, IOSPlugin.kConfigKey),
-          '/path/to/test/darwin/test/Package.swift',
-        );
-        expect(
-          plugin.pluginSwiftPackageManifestPath(fs, MacOSPlugin.kConfigKey),
-          '/path/to/test/darwin/test/Package.swift',
-        );
-      });
-
-      testWithoutContext('pluginSwiftPackageManifestPath for non darwin plugins', () async {
-        final MemoryFileSystem fs = MemoryFileSystem.test();
-        final Plugin plugin = Plugin(
-          name: 'test',
-          path: '/path/to/test/',
-          defaultPackagePlatforms: const <String, String>{},
-          pluginDartClassPlatforms: const <String, DartPluginClassAndFilePair>{},
-          platforms: const <String, PluginPlatform>{
-            WindowsPlugin.kConfigKey: WindowsPlugin(name: 'test', pluginClass: ''),
-          },
-          dependencies: <String>[],
-          isDirectDependency: true,
-          isDevDependency: false,
-        );
-
-        expect(plugin.pluginSwiftPackageManifestPath(fs, IOSPlugin.kConfigKey), isNull);
-        expect(plugin.pluginSwiftPackageManifestPath(fs, MacOSPlugin.kConfigKey), isNull);
-        expect(plugin.pluginSwiftPackageManifestPath(fs, WindowsPlugin.kConfigKey), isNull);
-      });
-
-      testWithoutContext('pluginPodspecPath for iOS and macOS plugins', () async {
-        final MemoryFileSystem fs = MemoryFileSystem.test();
-        final Plugin plugin = Plugin(
-          name: 'test',
-          path: '/path/to/test/',
-          defaultPackagePlatforms: const <String, String>{},
-          pluginDartClassPlatforms: const <String, DartPluginClassAndFilePair>{},
-          platforms: const <String, PluginPlatform>{
-            IOSPlugin.kConfigKey: IOSPlugin(name: 'test', classPrefix: ''),
-            MacOSPlugin.kConfigKey: MacOSPlugin(name: 'test'),
-          },
-          dependencies: <String>[],
-          isDirectDependency: true,
-          isDevDependency: false,
-        );
-
         expect(
           plugin.pluginPodspecPath(fs, IOSPlugin.kConfigKey),
           '/path/to/test/ios/test.podspec',
@@ -2255,7 +2191,7 @@ flutter:
         );
       });
 
-      testWithoutContext('pluginPodspecPath for darwin plugins', () async {
+      testWithoutContext('for SwiftPM and podspec paths for darwin plugins', () async {
         final MemoryFileSystem fs = MemoryFileSystem.test();
         final Plugin plugin = Plugin(
           name: 'test',
@@ -2275,6 +2211,22 @@ flutter:
           isDevDependency: false,
         );
 
+        expect(
+          plugin.pluginSwiftPackagePath(fs, IOSPlugin.kConfigKey),
+          '/path/to/test/darwin/test',
+        );
+        expect(
+          plugin.pluginSwiftPackagePath(fs, MacOSPlugin.kConfigKey),
+          '/path/to/test/darwin/test',
+        );
+        expect(
+          plugin.pluginSwiftPackageManifestPath(fs, IOSPlugin.kConfigKey),
+          '/path/to/test/darwin/test/Package.swift',
+        );
+        expect(
+          plugin.pluginSwiftPackageManifestPath(fs, MacOSPlugin.kConfigKey),
+          '/path/to/test/darwin/test/Package.swift',
+        );
         expect(
           plugin.pluginPodspecPath(fs, IOSPlugin.kConfigKey),
           '/path/to/test/darwin/test.podspec',
@@ -2285,7 +2237,7 @@ flutter:
         );
       });
 
-      testWithoutContext('pluginPodspecPath for non darwin plugins', () async {
+      testWithoutContext('for SwiftPM and podspec paths for non darwin plugins', () async {
         final MemoryFileSystem fs = MemoryFileSystem.test();
         final Plugin plugin = Plugin(
           name: 'test',
@@ -2300,6 +2252,12 @@ flutter:
           isDevDependency: false,
         );
 
+        expect(plugin.pluginSwiftPackagePath(fs, IOSPlugin.kConfigKey), isNull);
+        expect(plugin.pluginSwiftPackagePath(fs, MacOSPlugin.kConfigKey), isNull);
+        expect(plugin.pluginSwiftPackagePath(fs, WindowsPlugin.kConfigKey), isNull);
+        expect(plugin.pluginSwiftPackageManifestPath(fs, IOSPlugin.kConfigKey), isNull);
+        expect(plugin.pluginSwiftPackageManifestPath(fs, MacOSPlugin.kConfigKey), isNull);
+        expect(plugin.pluginSwiftPackageManifestPath(fs, WindowsPlugin.kConfigKey), isNull);
         expect(plugin.pluginPodspecPath(fs, IOSPlugin.kConfigKey), isNull);
         expect(plugin.pluginPodspecPath(fs, MacOSPlugin.kConfigKey), isNull);
         expect(plugin.pluginPodspecPath(fs, WindowsPlugin.kConfigKey), isNull);

packages/flutter_tools/test/general.shard/xcode_project_test.dart

@@ -51,6 +51,21 @@ void main() {
       expect(project.ephemeralDirectory.path, 'app_name/.ios/Flutter/ephemeral');
     });
 
+    testWithoutContext('flutterSwiftPackagesDirectory', () {
+      final MemoryFileSystem fs = MemoryFileSystem.test();
+      final IosProject project = IosProject.fromFlutter(FakeFlutterProject(fileSystem: fs));
+      expect(project.flutterSwiftPackagesDirectory.path, 'app_name/ios/Flutter/ephemeral/Packages');
+    });
+
+    testWithoutContext('relativeSwiftPackagesDirectory', () {
+      final MemoryFileSystem fs = MemoryFileSystem.test();
+      final IosProject project = IosProject.fromFlutter(FakeFlutterProject(fileSystem: fs));
+      expect(
+        project.relativeSwiftPackagesDirectory.path,
+        'app_name/ios/Flutter/ephemeral/Packages/.packages',
+      );
+    });
+
     testWithoutContext('flutterPluginSwiftPackageDirectory', () {
       final MemoryFileSystem fs = MemoryFileSystem.test();
       final IosProject project = IosProject.fromFlutter(FakeFlutterProject(fileSystem: fs));
@@ -440,6 +455,24 @@ void main() {
       expect(project.ephemeralDirectory.path, 'app_name/macos/Flutter/ephemeral');
     });
 
+    testWithoutContext('flutterSwiftPackagesDirectory', () {
+      final MemoryFileSystem fs = MemoryFileSystem.test();
+      final MacOSProject project = MacOSProject.fromFlutter(FakeFlutterProject(fileSystem: fs));
+      expect(
+        project.flutterSwiftPackagesDirectory.path,
+        'app_name/macos/Flutter/ephemeral/Packages',
+      );
+    });
+
+    testWithoutContext('relativeSwiftPackagesDirectory', () {
+      final MemoryFileSystem fs = MemoryFileSystem.test();
+      final MacOSProject project = MacOSProject.fromFlutter(FakeFlutterProject(fileSystem: fs));
+      expect(
+        project.relativeSwiftPackagesDirectory.path,
+        'app_name/macos/Flutter/ephemeral/Packages/.packages',
+      );
+    });
+
     testWithoutContext('flutterPluginSwiftPackageDirectory', () {
       final MemoryFileSystem fs = MemoryFileSystem.test();
       final MacOSProject project = MacOSProject.fromFlutter(FakeFlutterProject(fileSystem: fs));

packages/flutter_tools/test/integration.shard/swift_package_manager_test.dart

@@ -101,6 +101,71 @@ void main() {
             flutterBin,
             workingDirectoryPath,
           );
+
+          // Create a SwiftPM plugin that depends on native code from another SwiftPM plugin
+          final SwiftPackageManagerPlugin createdSwiftPMPlugin =
+              await SwiftPackageManagerUtils.createPlugin(
+                flutterBin,
+                workingDirectoryPath,
+                platform: platformName,
+                iosLanguage: iosLanguage,
+                usesSwiftPackageManager: true,
+              );
+          final File swiftPMPluginPackageManifest = fileSystem
+              .directory(createdSwiftPMPlugin.pluginPath)
+              .childDirectory(platformName)
+              .childDirectory(createdSwiftPMPlugin.pluginName)
+              .childFile('Package.swift');
+          final String manifestContents = swiftPMPluginPackageManifest.readAsStringSync();
+          swiftPMPluginPackageManifest.writeAsStringSync(
+            manifestContents
+                .replaceFirst(
+                  'dependencies: []',
+                  'dependencies: [.package(name: "${integrationTestPlugin.pluginName}", path: "../${integrationTestPlugin.pluginName}")]',
+                )
+                .replaceFirst(
+                  'dependencies: []',
+                  'dependencies: [.product(name: "${integrationTestPlugin.pluginName.replaceAll('_', '-')}", package: "${integrationTestPlugin.pluginName}")]',
+                ),
+          );
+          final File swiftPMPluginPodspec = fileSystem
+              .directory(createdSwiftPMPlugin.pluginPath)
+              .childDirectory(platformName)
+              .childFile('${createdSwiftPMPlugin.pluginName}.podspec');
+          final String podspecContents = swiftPMPluginPodspec.readAsStringSync();
+          swiftPMPluginPodspec.writeAsStringSync(
+            podspecContents.replaceFirst(
+              '\nend',
+              "\n  s.dependency '${integrationTestPlugin.pluginName}'\n\nend",
+            ),
+          );
+          final String pluginClassFileName =
+              iosLanguage == 'swift'
+                  ? '${createdSwiftPMPlugin.className}.swift'
+                  : '${createdSwiftPMPlugin.className}.m';
+          final String pluginClassFileImport =
+              iosLanguage == 'swift'
+                  ? 'import ${integrationTestPlugin.pluginName}'
+                  : '@import ${integrationTestPlugin.pluginName};';
+          final File pluginClassFile = fileSystem
+              .directory(createdSwiftPMPlugin.pluginPath)
+              .childDirectory(platformName)
+              .childDirectory(createdSwiftPMPlugin.pluginName)
+              .childDirectory('Sources')
+              .childDirectory(createdSwiftPMPlugin.pluginName)
+              .childFile(pluginClassFileName);
+          final String pluginClassFileContent = pluginClassFile.readAsStringSync();
+          pluginClassFile.writeAsStringSync('$pluginClassFileImport\n$pluginClassFileContent');
+          SwiftPackageManagerUtils.addDependency(
+            appDirectoryPath: createdSwiftPMPlugin.pluginPath,
+            plugin: integrationTestPlugin,
+          );
+
+          SwiftPackageManagerUtils.addDependency(
+            appDirectoryPath: appDirectoryPath,
+            plugin: createdSwiftPMPlugin,
+          );
+
           await SwiftPackageManagerUtils.buildApp(
             flutterBin,
             appDirectoryPath,
@@ -731,9 +796,9 @@ void main() {
     expect(generatedManifestFile, exists);
 
     String generatedManifest = generatedManifestFile.readAsStringSync();
-    final String generatedSwiftDependency = '''
+    const String generatedSwiftDependency = '''
     dependencies: [
-        .package(name: "integration_test", path: "${integrationTestPlugin.swiftPackagePlatformPath}")
+        .package(name: "integration_test", path: "../.packages/integration_test")
     ],
 ''';
 
@@ -828,9 +893,9 @@ void main() {
 
     String xcodeProject = xcodeProjectFile.readAsStringSync();
     String generatedManifest = generatedManifestFile.readAsStringSync();
-    final String generatedSwiftDependency = '''
+    const String generatedSwiftDependency = '''
     dependencies: [
-        .package(name: "integration_test", path: "${integrationTestPlugin.swiftPackagePlatformPath}")
+        .package(name: "integration_test", path: "../.packages/integration_test")
     ],
 ''';
 

packages/flutter_tools/test/integration.shard/swift_package_manager_utils.dart

@@ -211,9 +211,15 @@ class SwiftPackageManagerUtils {
       pluginName: pluginName,
       pluginPath: pluginDirectory.path,
       platform: platform,
+      className:
+          '${_capitalize(platform)}${_capitalize(iosLanguage)}${_capitalize(dependencyManager)}Plugin',
     );
   }
 
+  static String _capitalize(String str) {
+    return str[0].toUpperCase() + str.substring(1);
+  }
+
   static void addDependency({
     required SwiftPackageManagerPlugin plugin,
     required String appDirectoryPath,
@@ -269,6 +275,7 @@ class SwiftPackageManagerUtils {
                 'integration_test',
                 'integration_test_macos',
               ),
+      className: 'IntegrationTestPlugin',
     );
   }
 
@@ -295,7 +302,7 @@ class SwiftPackageManagerUtils {
       if (swiftPackageMangerEnabled) {
         expectedLines.addAll(<Pattern>[
           RegExp(
-            '${swiftPackagePlugin.pluginName}: [/private]*${swiftPackagePlugin.pluginPath}/$platform/${swiftPackagePlugin.pluginName} @ local',
+            '${swiftPackagePlugin.pluginName}: [/private]*$appPlatformDirectoryPath/Flutter/ephemeral/Packages/.packages/${swiftPackagePlugin.pluginName} @ local',
           ),
           "➜ Explicit dependency on target '${swiftPackagePlugin.pluginName}' in project '${swiftPackagePlugin.pluginName}'",
         ]);
@@ -335,6 +342,8 @@ class SwiftPackageManagerUtils {
     bool migrated = false,
   }) {
     final String frameworkName = platform == 'ios' ? 'Flutter' : 'FlutterMacOS';
+    final String appPlatformDirectoryPath = fileSystem.path.join(appDirectoryPath, platform);
+
     final List<String> unexpectedLines = <String>[];
     if (cocoaPodsPlugin == null && !migrated) {
       unexpectedLines.addAll(<String>[
@@ -351,7 +360,7 @@ class SwiftPackageManagerUtils {
         ]);
       } else {
         unexpectedLines.addAll(<String>[
-          '${swiftPackagePlugin.pluginName}: ${swiftPackagePlugin.pluginPath}/$platform/${swiftPackagePlugin.pluginName} @ local',
+          '${swiftPackagePlugin.pluginName}: $appPlatformDirectoryPath/Flutter/ephemeral/Packages/.packages/${swiftPackagePlugin.pluginName} @ local',
           "➜ Explicit dependency on target '${swiftPackagePlugin.pluginName}' in project '${swiftPackagePlugin.pluginName}'",
         ]);
       }
@@ -368,11 +377,13 @@ class SwiftPackageManagerPlugin {
     required this.pluginName,
     required this.pluginPath,
     required this.platform,
+    required this.className,
   });
 
   final String pluginName;
   final String pluginPath;
   final String platform;
+  final String className;
   String get exampleAppPath => fileSystem.path.join(pluginPath, 'example');
   String get exampleAppPlatformPath => fileSystem.path.join(exampleAppPath, platform);
   String get swiftPackagePlatformPath => fileSystem.path.join(pluginPath, platform, pluginName);