[flutter_plugin_tools] Allow disabling Swift Package Manager when building examples

script/tool/lib/src/build_examples_command.dart

@@ -61,7 +61,7 @@ class BuildExamplesCommand extends PackageLoopingCommand {
       defaultsTo: '',
       help: 'Enables the given Dart SDK experiments.',
     );
-    argParser.addFlag(_swiftPackageManagerFlag);
+    argParser.addFlag(_swiftPackageManagerFlag, defaultsTo: null);
   }
 
   // Maps the switch this command uses to identify a platform to information
@@ -115,13 +115,22 @@ class BuildExamplesCommand extends PackageLoopingCommand {
       'single key "$_pluginToolsConfigGlobalKey" containing a list of build '
       'arguments.';
 
-  /// Returns true if `--swift-package-manager` flag was passed along with
-  /// either `--ios` or `--macos`.
-  bool get usingSwiftPackageManager {
+  /// Returns whether the Swift Package Manager feature should be enabled,
+  /// disabled, or left to the release channel's default value.
+  bool? get _swiftPackageManagerFeatureConfig {
     final List<String> platformFlags = _platforms.keys.toList();
-    return getBoolArg(_swiftPackageManagerFlag) &&
-        (platformFlags.contains(platformIOS) ||
-            platformFlags.contains(platformMacOS));
+    if (!platformFlags.contains(platformIOS) &&
+        !platformFlags.contains(platformMacOS)) {
+      return null;
+    }
+
+    // TODO(loic-sharma): Allow enabling on stable once Swift Package Manager
+    // feature is available on stable.
+    if (platform.environment['CHANNEL'] != 'master') {
+      return null;
+    }
+
+    return getNullableBoolArg(_swiftPackageManagerFlag);
   }
 
   @override
@@ -135,15 +144,21 @@ class BuildExamplesCommand extends PackageLoopingCommand {
       throw ToolExit(_exitNoPlatformFlags);
     }
 
-    // TODO(vashworth): Enable on stable once Swift Package Manager feature is
-    // available on stable.
-    if (usingSwiftPackageManager &&
-        platform.environment['CHANNEL'] != 'stable') {
-      await processRunner.runAndStream(
-        flutterCommand,
-        <String>['config', '--enable-swift-package-manager'],
-        exitOnError: true,
-      );
+    switch (_swiftPackageManagerFeatureConfig) {
+      case true:
+        await processRunner.runAndStream(
+          flutterCommand,
+          <String>['config', '--enable-swift-package-manager'],
+          exitOnError: true,
+        );
+      case false:
+        await processRunner.runAndStream(
+          flutterCommand,
+          <String>['config', '--no-enable-swift-package-manager'],
+          exitOnError: true,
+        );
+      case null:
+        break;
     }
   }
 

script/tool/lib/src/common/package_command.dart

@@ -230,6 +230,11 @@ abstract class PackageCommand extends Command<void> {
     return (argResults![key] as bool?) ?? false;
   }
 
+  /// Convenience accessor for boolean arguments.
+  bool? getNullableBoolArg(String key) {
+    return argResults![key] as bool?;
+  }
+
   /// Convenience accessor for String arguments.
   String getStringArg(String key) {
     return (argResults![key] as String?) ?? '';

script/tool/test/build_examples_command_test.dart

@@ -164,6 +164,53 @@ void main() {
           ]));
     });
 
+    test('building for iOS with CocoaPods on master channel', () async {
+      mockPlatform.isMacOS = true;
+      mockPlatform.environment['CHANNEL'] = 'master';
+
+      final RepositoryPackage plugin = createFakePlugin('plugin', packagesDir,
+          platformSupport: <String, PlatformDetails>{
+            platformIOS: const PlatformDetails(PlatformSupport.inline),
+          });
+
+      final Directory pluginExampleDirectory = getExampleDir(plugin);
+
+      final List<String> output = await runCapturingPrint(runner, <String>[
+        'build-examples',
+        '--ios',
+        '--enable-experiment=exp1',
+        '--no-swift-package-manager',
+      ]);
+
+      expect(
+        output,
+        containsAllInOrder(<String>[
+          '\nBUILDING plugin/example for iOS',
+        ]),
+      );
+
+      expect(
+        processRunner.recordedCalls,
+        orderedEquals(<ProcessCall>[
+          ProcessCall(
+            getFlutterCommand(mockPlatform),
+            const <String>['config', '--no-enable-swift-package-manager'],
+            null,
+          ),
+          ProcessCall(
+            getFlutterCommand(mockPlatform),
+            const <String>[
+              'build',
+              'ios',
+              '--no-codesign',
+              '--enable-experiment=exp1'
+            ],
+            pluginExampleDirectory.path,
+          ),
+        ]),
+      );
+    });
+
     test('building for iOS with Swift Package Manager on master channel',
         () async {
       mockPlatform.isMacOS = true;
@@ -212,6 +259,50 @@ void main() {
       );
     });
 
+    test(
+        'building for iOS with CocoaPods on stable channel does not disable SPM',
+        () async {
+      mockPlatform.isMacOS = true;
+      mockPlatform.environment['CHANNEL'] = 'stable';
+
+      final RepositoryPackage plugin = createFakePlugin('plugin', packagesDir,
+          platformSupport: <String, PlatformDetails>{
+            platformIOS: const PlatformDetails(PlatformSupport.inline),
+          });
+
+      final Directory pluginExampleDirectory = getExampleDir(plugin);
+
+      final List<String> output = await runCapturingPrint(runner, <String>[
+        'build-examples',
+        '--ios',
+        '--enable-experiment=exp1',
+        '--no-swift-package-manager',
+      ]);
+
+      expect(
+        output,
+        containsAllInOrder(<String>[
+          '\nBUILDING plugin/example for iOS',
+        ]),
+      );
+
+      expect(
+        processRunner.recordedCalls,
+        orderedEquals(<ProcessCall>[
+          ProcessCall(
+            getFlutterCommand(mockPlatform),
+            const <String>[
+              'build',
+              'ios',
+              '--no-codesign',
+              '--enable-experiment=exp1'
+            ],
+            pluginExampleDirectory.path,
+          ),
+        ]),
+      );
+    });
+
     test(
         'building for iOS with Swift Package Manager on stable channel does not enable SPM',
         () async {
@@ -353,6 +444,48 @@ void main() {
           ]));
     });
 
+    test('building for macOS with CocoaPods on master channel', () async {
+      mockPlatform.isMacOS = true;
+      mockPlatform.environment['CHANNEL'] = 'master';
+
+      final RepositoryPackage plugin = createFakePlugin('plugin', packagesDir,
+          platformSupport: <String, PlatformDetails>{
+            platformMacOS: const PlatformDetails(PlatformSupport.inline),
+          });
+
+      final Directory pluginExampleDirectory = getExampleDir(plugin);
+
+      final List<String> output = await runCapturingPrint(runner,
+          <String>['build-examples', '--macos', '--no-swift-package-manager']);
+
+      expect(
+        output,
+        containsAllInOrder(<String>[
+          '\nBUILDING plugin/example for macOS',
+        ]),
+      );
+
+      expect(
+        processRunner.recordedCalls,
+        orderedEquals(<ProcessCall>[
+          ProcessCall(
+            getFlutterCommand(mockPlatform),
+            const <String>['config', '--no-enable-swift-package-manager'],
+            null,
+          ),
+          ProcessCall(
+            getFlutterCommand(mockPlatform),
+            const <String>[
+              'build',
+              'macos',
+            ],
+            pluginExampleDirectory.path,
+          ),
+        ]),
+      );
+    });
+
+
     test('building for macOS with Swift Package Manager on master channel',
         () async {
       mockPlatform.isMacOS = true;
@@ -395,6 +528,44 @@ void main() {
       );
     });
 
+    test(
+        'building for macOS with CocoaPods on stable channel does not disable SPM',
+        () async {
+      mockPlatform.isMacOS = true;
+      mockPlatform.environment['CHANNEL'] = 'stable';
+
+      final RepositoryPackage plugin = createFakePlugin('plugin', packagesDir,
+          platformSupport: <String, PlatformDetails>{
+            platformMacOS: const PlatformDetails(PlatformSupport.inline),
+          });
+
+      final Directory pluginExampleDirectory = getExampleDir(plugin);
+
+      final List<String> output = await runCapturingPrint(runner,
+          <String>['build-examples', '--macos', '--no-swift-package-manager']);
+
+      expect(
+        output,
+        containsAllInOrder(<String>[
+          '\nBUILDING plugin/example for macOS',
+        ]),
+      );
+
+      expect(
+        processRunner.recordedCalls,
+        orderedEquals(<ProcessCall>[
+          ProcessCall(
+            getFlutterCommand(mockPlatform),
+            const <String>[
+              'build',
+              'macos',
+            ],
+            pluginExampleDirectory.path,
+          ),
+        ]),
+      );
+    });
+
     test(
         'building for macOS with Swift Package Manager on stable channel does not enable SPM',
         () async {