| // Copyright (c) 2020, 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 '../analyzer.dart'; |
| |
| const _desc = r'Use raw string to avoid escapes.'; |
| |
| const _details = r''' |
| |
| A raw string can be used to avoid escaping only backslashes and dollars. |
| |
| **BAD:** |
| ``` |
| var s = 'A string with only \\ and \$'; |
| ``` |
| |
| **GOOD:** |
| ``` |
| var s = r'A string with only \ and $'; |
| ``` |
| |
| '''; |
| |
| class UseRawStrings extends LintRule implements NodeLintRule { |
| UseRawStrings() |
| : super( |
| name: 'use_raw_strings', |
| description: _desc, |
| details: _details, |
| group: Group.style); |
| |
| @override |
| void registerNodeProcessors( |
| NodeLintRegistry registry, LinterContext context) { |
| final visitor = _Visitor(this); |
| registry.addSimpleStringLiteral(this, visitor); |
| } |
| } |
| |
| class _Visitor extends SimpleAstVisitor { |
| final LintRule rule; |
| |
| _Visitor(this.rule); |
| |
| @override |
| void visitSimpleStringLiteral(SimpleStringLiteral node) { |
| if (node.isRaw) return; |
| |
| final lexeme = node.literal.lexeme.substring( |
| node.contentsOffset - node.literal.offset, |
| node.contentsEnd - node.literal.offset); |
| var hasEscape = false; |
| for (var i = 0; i < lexeme.length - 1; i++) { |
| var current = lexeme[i]; |
| if (current == r'\') { |
| hasEscape = true; |
| i += 1; |
| current = lexeme[i]; |
| if (current != r'\' && current != r'$') { |
| return; |
| } |
| } |
| } |
| if (hasEscape) { |
| rule.reportLint(node); |
| } |
| } |
| } |