[flutter_tools] handle case where file is deleted by other program or running...

[flutter_tools] handle case where file is deleted by other program or running on read only volume (#66708)

* [flutter_tools] handle case where file is deleted by other program

* Add test cases

* Update file_system.dart

* Update file_system_test.dart

* fix import

* make a static on ErrorHandligFS

* add support for no exit on failure

* address comments

* update doc comment to file or directory

packages/flutter_tools/lib/src/base/error_handling_io.dart

@@ -63,6 +63,40 @@ class ErrorHandlingFileSystem extends ForwardingFileSystem {
     }
   }
 
+  /// Delete the file or directory and return true if it exists, take no
+  /// action and return false if it does not.
+  ///
+  /// This method should be prefered to checking if it exists and
+  /// then deleting, because it handles the edge case where the file or directory
+  /// is deleted by a different program between the two calls.
+  static bool deleteIfExists(FileSystemEntity file, {bool recursive = false}) {
+    if (!file.existsSync()) {
+      return false;
+    }
+    try {
+      file.deleteSync(recursive: recursive);
+    } on FileSystemException catch (err) {
+      // Certain error codes indicate the file could not be found. It could have
+      // been deleted by a different program while the tool was running.
+      // if it still exists, the file likely exists on a read-only volume.
+      //
+      // On windows this is error code 2: ERROR_FILE_NOT_FOUND, and on
+      // macOS/Linux it is error code 2/ENOENT: No such file or directory.
+      const int kSystemCannotFindFile = 2;
+      if (err?.osError?.errorCode != kSystemCannotFindFile || _noExitOnFailure) {
+        rethrow;
+      }
+      if (file.existsSync()) {
+        throwToolExit(
+          'The Flutter tool tried to delete the file or directory ${file.path} but was '
+          'unable to. This may be due to the file and/or project\'s location on a read-only '
+          'volume. Consider relocating the project and trying again',
+        );
+      }
+    }
+    return true;
+  }
+
   static bool _noExitOnFailure = false;
 
   @override

packages/flutter_tools/lib/src/build_system/build_system.dart

@@ -10,6 +10,7 @@ import 'package:pool/pool.dart';
 import 'package:process/process.dart';
 
 import '../artifacts.dart';
+import '../base/error_handling_io.dart';
 import '../base/file_system.dart';
 import '../base/logger.dart';
 import '../base/platform.dart';
@@ -160,9 +161,7 @@ abstract class Target {
   /// Invoke to remove the stamp file if the [buildAction] threw an exception.
   void clearStamp(Environment environment) {
     final File stamp = _findStampFile(environment);
-    if (stamp.existsSync()) {
-      stamp.deleteSync();
-    }
+    ErrorHandlingFileSystem.deleteIfExists(stamp);
   }
 
   void _writeStamp(
@@ -697,9 +696,7 @@ class FlutterBuildSystem extends BuildSystem {
     for (final String lastOutput in lastOutputs) {
       if (!currentOutputs.containsKey(lastOutput)) {
         final File lastOutputFile = fileSystem.file(lastOutput);
-        if (lastOutputFile.existsSync()) {
-          lastOutputFile.deleteSync();
-        }
+        ErrorHandlingFileSystem.deleteIfExists(lastOutputFile);
       }
     }
   }
@@ -820,9 +817,7 @@ class _BuildInstance {
           continue;
         }
         final File previousFile = fileSystem.file(previousOutput);
-        if (previousFile.existsSync()) {
-          previousFile.deleteSync();
-        }
+        ErrorHandlingFileSystem.deleteIfExists(previousFile);
       }
     } on Exception catch (exception, stackTrace) {
       // TODO(jonahwilliams): throw specific exception for expected errors to mark

packages/flutter_tools/lib/src/build_system/depfile.dart

@@ -4,6 +4,7 @@
 
 import 'package:meta/meta.dart';
 
+import '../base/error_handling_io.dart';
 import '../base/file_system.dart';
 import '../base/logger.dart';
 
@@ -26,9 +27,7 @@ class DepfileService {
   /// exist.
   void writeToFile(Depfile depfile, File output) {
     if (depfile.inputs.isEmpty || depfile.outputs.isEmpty) {
-      if (output.existsSync()) {
-        output.deleteSync();
-      }
+      ErrorHandlingFileSystem.deleteIfExists(output);
       return;
     }
     final StringBuffer buffer = StringBuffer();

packages/flutter_tools/lib/src/cache.dart

@@ -10,6 +10,7 @@ import 'package:process/process.dart';
 
 import 'android/gradle_utils.dart';
 import 'base/common.dart';
+import 'base/error_handling_io.dart';
 import 'base/file_system.dart';
 import 'base/io.dart' show HttpClient, HttpClientRequest, HttpClientResponse, HttpStatus, ProcessException, SocketException;
 import 'base/logger.dart';
@@ -436,9 +437,7 @@ class Cache {
       getStampFileFor('flutter_tools').deleteSync();
       for (final ArtifactSet artifact in _artifacts) {
         final File file = getStampFileFor(artifact.stampName);
-        if (file.existsSync()) {
-          file.deleteSync();
-        }
+        ErrorHandlingFileSystem.deleteIfExists(file);
       }
     } on FileSystemException catch (err) {
       _logger.printError('Failed to delete some stamp files: $err');

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

@@ -7,6 +7,7 @@ import 'package:meta/meta.dart';
 import 'package:process/process.dart';
 
 import '../base/common.dart';
+import '../base/error_handling_io.dart';
 import '../base/file_system.dart';
 import '../base/io.dart';
 import '../base/logger.dart';
@@ -307,9 +308,7 @@ class CocoaPods {
   /// Ensures that pod install is deemed needed on next check.
   void invalidatePodInstallOutput(XcodeBasedProject xcodeProject) {
     final File manifestLock = xcodeProject.podManifestLock;
-    if (manifestLock.existsSync()) {
-      manifestLock.deleteSync();
-    }
+    ErrorHandlingFileSystem.deleteIfExists(manifestLock);
   }
 
   // Check if you need to run pod install.

packages/flutter_tools/lib/src/plugins.dart

@@ -9,6 +9,7 @@ import 'package:yaml/yaml.dart';
 
 import 'android/gradle.dart';
 import 'base/common.dart';
+import 'base/error_handling_io.dart';
 import 'base/file_system.dart';
 import 'convert.dart';
 import 'dart/package_map.dart';
@@ -435,11 +436,7 @@ const String _kFlutterPluginsDependenciesKey = 'dependencies';
 bool _writeFlutterPluginsList(FlutterProject project, List<Plugin> plugins) {
   final File pluginsFile = project.flutterPluginsDependenciesFile;
   if (plugins.isEmpty) {
-    if (pluginsFile.existsSync()) {
-      pluginsFile.deleteSync();
-      return true;
-    }
-    return false;
+    return ErrorHandlingFileSystem.deleteIfExists(pluginsFile);
   }
 
   final String iosKey = project.ios.pluginConfigKey;
@@ -506,11 +503,7 @@ List<dynamic> _createPluginLegacyDependencyGraph(List<Plugin> plugins) {
 bool _writeFlutterPluginsListLegacy(FlutterProject project, List<Plugin> plugins) {
   final File pluginsFile = project.flutterPluginsFile;
   if (plugins.isEmpty) {
-    if (pluginsFile.existsSync()) {
-      pluginsFile.deleteSync();
-      return true;
-    }
-    return false;
+    return ErrorHandlingFileSystem.deleteIfExists(pluginsFile);
   }
 
   const String info = 'This is a generated file; do not edit or check into version control.';
@@ -1051,9 +1044,7 @@ Future<void> _writeWebPluginRegistrant(FlutterProject project, List<Plugin> plug
   final String filePath = globals.fs.path.join(registryDirectory, 'generated_plugin_registrant.dart');
   if (webPlugins.isEmpty) {
     final File file = globals.fs.file(filePath);
-    if (file.existsSync()) {
-      file.deleteSync();
-    }
+    return ErrorHandlingFileSystem.deleteIfExists(file);
   } else {
     _renderTemplateToFile(
       _dartPluginRegistryTemplate,

packages/flutter_tools/lib/src/tracing.dart

@@ -3,14 +3,15 @@
 // found in the LICENSE file.
 
 import 'dart:async';
+
 import 'package:meta/meta.dart';
 import 'package:vm_service/vm_service.dart' as vm_service;
 
 import 'base/common.dart';
+import 'base/error_handling_io.dart';
 import 'base/file_system.dart';
 import 'base/logger.dart';
 import 'base/utils.dart';
-
 import 'vmservice.dart';
 
 // Names of some of the Timeline events we care about.
@@ -94,9 +95,7 @@ Future<void> downloadStartupTrace(vm_service.VmService vmService, {
   final File traceInfoFile = output.childFile('start_up_info.json');
 
   // Delete old startup data, if any.
-  if (traceInfoFile.existsSync()) {
-    traceInfoFile.deleteSync();
-  }
+  ErrorHandlingFileSystem.deleteIfExists(traceInfoFile);
 
   // Create "build" directory, if missing.
   if (!traceInfoFile.parent.existsSync()) {

packages/flutter_tools/test/commands.shard/permeable/analyze_once_test.dart

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:flutter_tools/src/base/error_handling_io.dart';
 import 'package:flutter_tools/src/globals.dart' as globals;
 import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/common.dart';
@@ -246,9 +247,7 @@ flutter_project:lib/
         exitCode: 1,
       );
     } finally {
-      if (optionsFile.existsSync()) {
-        optionsFile.deleteSync();
-      }
+      ErrorHandlingFileSystem.deleteIfExists(optionsFile);
     }
   });
 

packages/flutter_tools/test/commands.shard/permeable/packages_test.dart

@@ -6,6 +6,7 @@ import 'dart:convert';
 
 import 'package:args/command_runner.dart';
 import 'package:flutter_tools/src/base/bot_detector.dart';
+import 'package:flutter_tools/src/base/error_handling_io.dart';
 import 'package:flutter_tools/src/base/file_system.dart' hide IOSink;
 import 'package:flutter_tools/src/base/io.dart';
 import 'package:flutter_tools/src/cache.dart';
@@ -182,9 +183,7 @@ void main() {
       ].expand<String>((List<String> list) => list);
       for (final String path in allFiles) {
         final File file = globals.fs.file(globals.fs.path.join(projectPath, path));
-        if (file.existsSync()) {
-          file.deleteSync();
-        }
+        ErrorHandlingFileSystem.deleteIfExists(file);
       }
     }
 

packages/flutter_tools/test/general.shard/base/error_handling_io_test.dart

@@ -111,6 +111,58 @@ void setupDirectoryMocks({
 }
 
 void main() {
+  testWithoutContext('deleteIfExists does not delete if file does not exist', () {
+    final File file = MockFile();
+    when(file.existsSync()).thenReturn(false);
+
+    expect(ErrorHandlingFileSystem.deleteIfExists(file), false);
+  });
+
+  testWithoutContext('deleteIfExists deletes if file exists', () {
+    final File file = MockFile();
+    when(file.existsSync()).thenReturn(true);
+
+     expect(ErrorHandlingFileSystem.deleteIfExists(file), true);
+  });
+
+  testWithoutContext('deleteIfExists handles separate program deleting file', () {
+    final File file = MockFile();
+    bool exists = true;
+    // Return true for the first call, false for any subsequent calls.
+    when(file.existsSync()).thenAnswer((Invocation _) {
+      final bool result = exists;
+      exists = false;
+      return result;
+    });
+    when(file.deleteSync(recursive: false))
+      .thenThrow(const FileSystemException('', '', OSError('', 2)));
+
+    expect(ErrorHandlingFileSystem.deleteIfExists(file), true);
+  });
+
+  testWithoutContext('deleteIfExists throws tool exit if file exists on read-only volume', () {
+    final File file = MockFile();
+    when(file.existsSync()).thenReturn(true);
+    when(file.deleteSync(recursive: false))
+      .thenThrow(const FileSystemException('', '', OSError('', 2)));
+
+    expect(() => ErrorHandlingFileSystem.deleteIfExists(file), throwsA(isA<ToolExit>()));
+  });
+
+  testWithoutContext('deleteIfExists does not tool exit if file exists on read-only '
+    'volume and it is run under noExitOnFailure', () {
+    final File file = MockFile();
+    when(file.existsSync()).thenReturn(true);
+    when(file.deleteSync(recursive: false))
+      .thenThrow(const FileSystemException('', '', OSError('', 2)));
+
+    expect(() {
+      ErrorHandlingFileSystem.noExitOnFailure(() {
+        ErrorHandlingFileSystem.deleteIfExists(file);
+      });
+    }, throwsA(isA<FileSystemException>()));
+  });
+
   group('throws ToolExit on Windows', () {
     const int kDeviceFull = 112;
     const int kUserMappedSectionOpened = 1224;

packages/flutter_tools/test/general.shard/base/file_system_test.dart

@@ -180,3 +180,4 @@ void main() {
 }
 
 class MockIoProcessSignal extends Mock implements io.ProcessSignal {}
+class MockFile extends Mock implements File {}