| // Copyright (c) 2018, 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/ast/ast.dart'; |
| import 'package:analyzer/dart/ast/visitor.dart'; |
| import 'package:linter/src/analyzer.dart'; |
| |
| const _desc = r'Unnecessary parenthesis can be removed.'; |
| |
| const _details = r''' |
| |
| **AVOID** using parenthesis when not needed. |
| |
| **GOOD:** |
| ``` |
| a = b; |
| ``` |
| |
| **BAD:** |
| ``` |
| a = (b); |
| ``` |
| |
| '''; |
| |
| class UnnecessaryParenthesis extends LintRule { |
| UnnecessaryParenthesis() |
| : super( |
| name: 'unnecessary_parenthesis', |
| description: _desc, |
| details: _details, |
| group: Group.style); |
| |
| @override |
| AstVisitor getVisitor() => new Visitor(this); |
| } |
| |
| class Visitor extends SimpleAstVisitor { |
| LintRule rule; |
| Visitor(this.rule); |
| |
| @override |
| visitParenthesizedExpression(ParenthesizedExpression node) { |
| if (node.expression is SimpleIdentifier) { |
| rule.reportLint(node); |
| return; |
| } |
| |
| final parent = node.parent; |
| |
| if (parent is ParenthesizedExpression) { |
| rule.reportLint(node); |
| return; |
| } |
| |
| if (parent is Expression) { |
| if (parent is BinaryExpression) return; |
| if (parent is ConditionalExpression) return; |
| if (parent is CascadeExpression) return; |
| if (parent.precedence < node.expression.precedence) { |
| rule.reportLint(node); |
| return; |
| } |
| } else { |
| rule.reportLint(node); |
| return; |
| } |
| } |
| } |