Skip podspec Swift Search Path validation if only swift file is Package.swift (#6627)

Usually when an iOS plugin uses Swift files, it requires a workaround in the podspec to add Swift to the search paths. Part of the `podspec-check` command is validating this workaround is found. However, when the only Swift file is the `Package.swift` (Swift Package Manager manifest), skip this validation since having this file does not indicate the plugin uses Swift files.

Fixes flutter/flutter#147548.

Author: vashworth

script/tool/lib/src/podspec_check_command.dart

@@ -161,8 +161,14 @@ class PodspecCheckCommand extends PackageLoopingCommand {
   }
 
   /// Returns true if there is any iOS plugin implementation code written in
-  /// Swift.
+  /// Swift. Skips files named "Package.swift", which is a Swift Pacakge Manager
+  /// manifest file and does not mean the plugin is written in Swift.
   Future<bool> _hasIOSSwiftCode(RepositoryPackage package) async {
+    final String iosSwiftPackageManifestPath = package
+        .platformDirectory(FlutterPlatform.ios)
+        .childDirectory(package.directory.basename)
+        .childFile('Package.swift')
+        .path;
     return getFilesForPackage(package).any((File entity) {
       final String relativePath =
           getRelativePosixPath(entity, from: package.directory);
@@ -171,7 +177,8 @@ class PodspecCheckCommand extends PackageLoopingCommand {
         return false;
       }
       final String filePath = entity.path;
-      return path.extension(filePath) == '.swift';
+      return filePath != iosSwiftPackageManifestPath &&
+          path.extension(filePath) == '.swift';
     });
   }
 

script/tool/test/license_check_command_test.dart

@@ -544,6 +544,23 @@ void main() {
             contains('  third_party/bad.cc'),
           ]));
     });
+
+    test('passes if Package.swift has license blocks', () async {
+      final File checked = root.childFile('Package.swift');
+      checked.createSync();
+      writeLicense(checked, prefix: '// swift-tools-version: 5.9\n');
+
+      final List<String> output =
+          await runCapturingPrint(runner, <String>['license-check']);
+
+      // Sanity check that the test did actually check a file.
+      expect(
+          output,
+          containsAllInOrder(<Matcher>[
+            contains('Checking Package.swift'),
+            contains('All files passed validation!'),
+          ]));
+    });
   });
 }
 

script/tool/test/podspec_check_command_test.dart

@@ -319,8 +319,14 @@ void main() {
 
     test('fails if an iOS Swift plugin is missing the search paths workaround',
         () async {
-      final RepositoryPackage plugin = createFakePlugin('plugin1', packagesDir,
-          extraFiles: <String>['ios/Classes/SomeSwift.swift']);
+      final RepositoryPackage plugin = createFakePlugin(
+        'plugin1',
+        packagesDir,
+        extraFiles: <String>[
+          'ios/Classes/SomeSwift.swift',
+          'ios/plugin1/Package.swift',
+        ],
+      );
       _writeFakePodspec(plugin, 'ios');
 
       Error? commandError;
@@ -378,6 +384,27 @@ void main() {
           ));
     });
 
+    test('does not require the search paths workaround for iOS Package.swift',
+        () async {
+      final RepositoryPackage plugin = createFakePlugin(
+        'plugin1',
+        packagesDir,
+        extraFiles: <String>['ios/plugin1/Package.swift'],
+      );
+      _writeFakePodspec(plugin, 'ios');
+
+      final List<String> output =
+          await runCapturingPrint(runner, <String>['podspec-check']);
+
+      expect(
+          output,
+          containsAllInOrder(
+            <Matcher>[
+              contains('Ran for 1 package(s)'),
+            ],
+          ));
+    });
+
     test('does not require the search paths workaround for macOS plugins',
         () async {
       final RepositoryPackage plugin = createFakePlugin('plugin1', packagesDir,