| // 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/token.dart'; |
| import 'package:analyzer/dart/ast/visitor.dart'; |
| |
| import '../analyzer.dart'; |
| |
| const _desc = r'Avoid const keyword.'; |
| |
| const _details = r''' |
| |
| **AVOID** repeating const keyword in a const context. |
| |
| **BAD:** |
| ```dart |
| class A { const A(); } |
| m(){ |
| const a = const A(); |
| final b = const [const A()]; |
| } |
| ``` |
| |
| **GOOD:** |
| ```dart |
| class A { const A(); } |
| m(){ |
| const a = A(); |
| final b = const [A()]; |
| } |
| ``` |
| |
| '''; |
| |
| class UnnecessaryConst extends LintRule implements NodeLintRule { |
| UnnecessaryConst() |
| : super( |
| name: 'unnecessary_const', |
| description: _desc, |
| details: _details, |
| group: Group.style); |
| |
| @override |
| void registerNodeProcessors( |
| NodeLintRegistry registry, LinterContext context) { |
| var visitor = _Visitor(this); |
| registry.addInstanceCreationExpression(this, visitor); |
| registry.addListLiteral(this, visitor); |
| registry.addSetOrMapLiteral(this, visitor); |
| } |
| } |
| |
| class _Visitor extends SimpleAstVisitor { |
| final LintRule rule; |
| _Visitor(this.rule); |
| |
| @override |
| void visitInstanceCreationExpression(InstanceCreationExpression node) { |
| if (node.keyword?.type != Keyword.CONST) return; |
| |
| if (node.inConstantContext) { |
| rule.reportLint(node); |
| } |
| } |
| |
| @override |
| void visitListLiteral(ListLiteral node) => _visitTypedLiteral(node); |
| |
| @override |
| void visitSetOrMapLiteral(SetOrMapLiteral node) { |
| _visitTypedLiteral(node); |
| } |
| |
| void _visitTypedLiteral(TypedLiteral node) { |
| if (node.constKeyword?.type != Keyword.CONST) return; |
| |
| if (node.inConstantContext) { |
| rule.reportLint(node); |
| } |
| } |
| } |