added cleanContext (#93264)

* added cleanContext

* using async

* added one more test

dev/conductor/core/lib/src/clean.dart

@@ -49,12 +49,11 @@ class CleanCommand extends Command<void> {
       'This will abort a work in progress release.';
 
   @override
-  void run() {
+  Future<void> run() {
     final ArgResults argumentResults = argResults!;
     final File stateFile = checkouts.fileSystem.file(argumentResults[kStateOption]);
     if (!stateFile.existsSync()) {
-      throw ConductorException(
+      throw ConductorException('No persistent state file found at ${stateFile.path}!');
-          'No persistent state file found at ${stateFile.path}!');
     }
 
     if (!(argumentResults[kYesFlag] as bool)) {
@@ -67,10 +66,28 @@ class CleanCommand extends Command<void> {
       // Only proceed if the first character of stdin is 'y' or 'Y'
       if (response.isEmpty || response[0].toLowerCase() != 'y') {
         stdio.printStatus('Aborting clean operation.');
-        return;
       }
     }
     stdio.printStatus('Deleting persistent state file ${stateFile.path}...');
-    stateFile.deleteSync();
+
+    final RunContext context = RunContext(
+      stateFile: stateFile,
+    );
+    return context.run();
+  }
+}
+
+/// Context for cleaning up persistent state file.
+///
+/// This is a frontend-agnostic implementation.
+class RunContext {
+  RunContext({
+    required this.stateFile,
+  });
+
+  final File stateFile;
+
+  Future<void> run() {
+    return stateFile.delete();
   }
 }

dev/conductor/core/test/clean_test.dart

@@ -15,6 +15,7 @@ void main() {
   group('clean command', () {
     const String flutterRoot = '/flutter';
     const String checkoutsParentDirectory = '$flutterRoot/dev/tools/';
+    const String stateFilePath = '/state-file.json';
 
     late MemoryFileSystem fileSystem;
     late FakePlatform platform;
@@ -47,24 +48,36 @@ void main() {
     });
 
     test('throws if no state file found', () async {
-      const String stateFile = '/state-file.json';
-
       await expectLater(
         () async => runner.run(<String>[
           'clean',
           '--$kStateOption',
-          stateFile,
+          stateFilePath,
           '--$kYesFlag',
         ]),
         throwsExceptionWith(
-          'No persistent state file found at $stateFile',
+          'No persistent state file found at $stateFilePath',
         ),
       );
     });
 
-    test('deletes state file', () async {
+    test('deletes an empty state file', () async {
-      final File stateFile = fileSystem.file('/state-file.json');
+      final File stateFile = fileSystem.file(stateFilePath);
-      stateFile.writeAsStringSync('{}');
+      stateFile.writeAsStringSync('');
+
+      await runner.run(<String>[
+        'clean',
+        '--$kStateOption',
+        stateFile.path,
+        '--$kYesFlag',
+      ]);
+
+      expect(stateFile.existsSync(), false);
+    });
+
+    test('deletes a state file with content', () async {
+      final File stateFile = fileSystem.file(stateFilePath);
+      stateFile.writeAsStringSync('{status: pending}');
 
       await runner.run(<String>[
         'clean',