| // Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| import 'package:analyzer/dart/element/type.dart'; |
| |
| import '../analyzer.dart'; |
| import '../util/dart_type_utilities.dart'; |
| import '../util/leak_detector_visitor.dart'; |
| |
| const _desc = r'Close instances of `dart.core.Sink`.'; |
| |
| const _details = r''' |
| |
| **DO** invoke `close` on instances of `dart.core.Sink`. |
| |
| Closing instances of Sink prevents memory leaks and unexpected behavior. |
| |
| **BAD:** |
| ``` |
| class A { |
| IOSink _sinkA; |
| void init(filename) { |
| _sinkA = new File(filename).openWrite(); // LINT |
| } |
| } |
| ``` |
| |
| **BAD:** |
| ``` |
| void someFunction() { |
| IOSink _sinkF; // LINT |
| } |
| ``` |
| |
| **GOOD:** |
| ``` |
| class B { |
| IOSink _sinkB; |
| void init(filename) { |
| _sinkB = new File(filename).openWrite(); // OK |
| } |
| |
| void dispose(filename) { |
| _sinkB.close(); |
| } |
| } |
| ``` |
| |
| **GOOD:** |
| ``` |
| void someFunctionOK() { |
| IOSink _sinkFOK; // OK |
| _sinkFOK.close(); |
| } |
| ``` |
| |
| '''; |
| |
| bool _isSink(DartType type) => |
| DartTypeUtilities.implementsInterface(type, 'Sink', 'dart.core'); |
| |
| bool _isSocket(DartType type) => |
| DartTypeUtilities.implementsInterface(type, 'Socket', 'dart.io'); |
| |
| class CloseSinks extends LintRule implements NodeLintRule { |
| CloseSinks() |
| : super( |
| name: 'close_sinks', |
| description: _desc, |
| details: _details, |
| group: Group.errors); |
| |
| @override |
| void registerNodeProcessors( |
| NodeLintRegistry registry, LinterContext context) { |
| final visitor = _Visitor(this); |
| registry.addFieldDeclaration(this, visitor); |
| registry.addVariableDeclarationStatement(this, visitor); |
| } |
| } |
| |
| class _Visitor extends LeakDetectorProcessors { |
| static const _closeMethodName = 'close'; |
| static const _destroyMethodName = 'destroy'; |
| |
| @override |
| Map<DartTypePredicate, String> predicates = { |
| _isSink: _closeMethodName, |
| _isSocket: _destroyMethodName |
| }; |
| |
| _Visitor(LintRule rule) : super(rule); |
| } |