[tool] Use flutter for pub commands when examples use Flutter

script/tool/lib/src/analyze_command.dart

@@ -323,6 +323,9 @@ class AnalyzeCommand extends PackageLoopingCommand {
       processRunner,
       platform,
       dartSdkPathOverride: _dartBinaryPath,
+      // 'get' and 'downgrade' resolve examples as well, so check
+      // those as well when deciding between `flutter` and `dart`.
+      recursiveFlutterCheck: true,
     );
   }
 

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

@@ -26,6 +26,7 @@ Future<bool> runPubGet(
     processRunner,
     platform,
     streamOutput: streamOutput,
+    recursiveFlutterCheck: true,
   );
 }
 
@@ -41,8 +42,14 @@ Future<bool> runPubCommand(
   Platform platform, {
   bool streamOutput = true,
   String? dartSdkPathOverride,
+  bool recursiveFlutterCheck = false,
 }) async {
-  final String command = _pubCommand(package, platform, dartSdkPathOverride: dartSdkPathOverride);
+  final String command = _pubCommand(
+    package,
+    platform,
+    dartSdkPathOverride: dartSdkPathOverride,
+    recursiveFlutterCheck: recursiveFlutterCheck,
+  );
   final args = <String>['pub', ...commandArgs];
   final int exitCode;
   if (streamOutput) {
@@ -78,10 +85,24 @@ Future<io.Process> startPubCommand(
   ], workingDirectory: package.directory);
 }
 
-String _pubCommand(RepositoryPackage package, Platform platform, {String? dartSdkPathOverride}) {
+String _pubCommand(
+  RepositoryPackage package,
+  Platform platform, {
+  String? dartSdkPathOverride,
+  bool recursiveFlutterCheck = false,
+}) {
   // Running `dart pub get` on a Flutter package can fail if a non-Flutter Dart
   // is first in the path, so use `flutter pub get` for any Flutter package.
-  return package.requiresFlutter()
+  bool useFlutter = package.requiresFlutter();
+  if (!useFlutter && recursiveFlutterCheck) {
+    for (final RepositoryPackage example in package.getExamples()) {
+      if (example.requiresFlutter()) {
+        useFlutter = true;
+        break;
+      }
+    }
+  }
+  return useFlutter
       ? (platform.isWindows ? 'flutter.bat' : 'flutter')
       : (dartSdkPathOverride ?? 'dart');
 }

script/tool/test/analyze_command_test.dart

@@ -175,6 +175,21 @@ void main() {
       );
     });
 
+    test('runs flutter pub get for non-Flutter packages with Flutter examples', () async {
+      final RepositoryPackage mainPackage = createFakePackage('a', packagesDir, examples: []);
+      createFakePackage('example', mainPackage.directory, examples: [], isFlutter: true);
+
+      await runCapturingPrint(runner, <String>['analyze']);
+
+      expect(
+        processRunner.recordedCalls,
+        orderedEquals(<ProcessCall>[
+          ProcessCall('flutter', const <String>['pub', 'get'], mainPackage.path),
+          ProcessCall('dart', const <String>['analyze', '--fatal-infos'], mainPackage.path),
+        ]),
+      );
+    });
+
     test('passes lib/ directory with --lib-only', () async {
       final RepositoryPackage package = createFakePackage('a_package', packagesDir);
 
@@ -254,16 +269,47 @@ void main() {
     });
 
     test('downgrades first when requested', () async {
-      final RepositoryPackage plugin = createFakePlugin('a', packagesDir);
+      final RepositoryPackage package = createFakePackage('a', packagesDir);
 
       await runCapturingPrint(runner, <String>['analyze', '--downgrade']);
 
       expect(
         processRunner.recordedCalls,
         orderedEquals(<ProcessCall>[
-          ProcessCall('flutter', const <String>['pub', 'downgrade'], plugin.path),
-          ProcessCall('flutter', const <String>['pub', 'get'], plugin.path),
-          ProcessCall('dart', const <String>['analyze', '--fatal-infos'], plugin.path),
+          ProcessCall('dart', const <String>['pub', 'downgrade'], package.path),
+          ProcessCall('dart', const <String>['pub', 'get'], package.path),
+          ProcessCall('dart', const <String>['analyze', '--fatal-infos'], package.path),
+        ]),
+      );
+    });
+
+    test('downgrades using flutter for Flutter packages', () async {
+      final RepositoryPackage package = createFakePackage('a', packagesDir, isFlutter: true);
+
+      await runCapturingPrint(runner, <String>['analyze', '--downgrade']);
+
+      expect(
+        processRunner.recordedCalls,
+        orderedEquals(<ProcessCall>[
+          ProcessCall('flutter', const <String>['pub', 'downgrade'], package.path),
+          ProcessCall('flutter', const <String>['pub', 'get'], package.path),
+          ProcessCall('dart', const <String>['analyze', '--fatal-infos'], package.path),
+        ]),
+      );
+    });
+
+    test('downgrades using flutter for non-Flutter packages with Flutter examples', () async {
+      final RepositoryPackage package = createFakePackage('a', packagesDir, examples: []);
+      createFakePackage('example', package.directory, examples: [], isFlutter: true);
+
+      await runCapturingPrint(runner, <String>['analyze', '--downgrade']);
+
+      expect(
+        processRunner.recordedCalls,
+        orderedEquals(<ProcessCall>[
+          ProcessCall('flutter', const <String>['pub', 'downgrade'], package.path),
+          ProcessCall('flutter', const <String>['pub', 'get'], package.path),
+          ProcessCall('dart', const <String>['analyze', '--fatal-infos'], package.path),
         ]),
       );
     });

script/tool/test/common/pub_utils_test.dart

@@ -17,7 +17,7 @@ void main() {
     (:packagesDir, :processRunner, gitProcessRunner: _, gitDir: _) = configureBaseCommandMocks();
   });
 
-  test('runs with Dart for a non-Flutter package by default', () async {
+  test('runs with Dart for a non-Flutter package', () async {
     final RepositoryPackage package = createFakePackage('a_package', packagesDir);
     final platform = MockPlatform();
 
@@ -31,7 +31,7 @@ void main() {
     );
   });
 
-  test('runs with Flutter for a Flutter package by default', () async {
+  test('runs with Flutter for a Flutter package', () async {
     final RepositoryPackage package = createFakePackage('a_package', packagesDir, isFlutter: true);
     final platform = MockPlatform();
 
@@ -45,6 +45,21 @@ void main() {
     );
   });
 
+  test('runs with Flutter for a non-Flutter package with a Flutter example', () async {
+    final RepositoryPackage package = createFakePackage('a_package', packagesDir, examples: []);
+    createFakePackage('example', package.directory, examples: [], isFlutter: true);
+    final platform = MockPlatform();
+
+    await runPubGet(package, processRunner, platform);
+
+    expect(
+      processRunner.recordedCalls,
+      orderedEquals(<ProcessCall>[
+        ProcessCall('flutter', const <String>['pub', 'get'], package.path),
+      ]),
+    );
+  });
+
   test('uses the correct Flutter command on Windows', () async {
     final RepositoryPackage package = createFakePackage('a_package', packagesDir, isFlutter: true);
     final platform = MockPlatform(isWindows: true);