unnecessary_raw_strings (#2001)
diff --git a/example/all.yaml b/example/all.yaml
index 70c84a4..97cb311 100644
--- a/example/all.yaml
+++ b/example/all.yaml
@@ -149,6 +149,7 @@
- unnecessary_null_in_if_null_operators
- unnecessary_overrides
- unnecessary_parenthesis
+ - unnecessary_raw_strings
- unnecessary_statements
- unnecessary_string_escapes
- unnecessary_string_interpolations
diff --git a/lib/src/rules.dart b/lib/src/rules.dart
index c37d3e9..d277fd0 100644
--- a/lib/src/rules.dart
+++ b/lib/src/rules.dart
@@ -152,6 +152,7 @@
import 'rules/unnecessary_null_in_if_null_operators.dart';
import 'rules/unnecessary_overrides.dart';
import 'rules/unnecessary_parenthesis.dart';
+import 'rules/unnecessary_raw_strings.dart';
import 'rules/unnecessary_statements.dart';
import 'rules/unnecessary_string_escapes.dart';
import 'rules/unnecessary_string_interpolations.dart';
@@ -323,6 +324,7 @@
..register(UnnecessaryLambdas())
..register(UnnecessaryOverrides())
..register(UnnecessaryParenthesis())
+ ..register(UnnecessaryRawStrings())
..register(UnnecessaryStatements())
..register(UnnecessaryStringEscapes())
..register(UnnecessaryStringInterpolations())
diff --git a/lib/src/rules/unnecessary_raw_strings.dart b/lib/src/rules/unnecessary_raw_strings.dart
new file mode 100644
index 0000000..3b41a6d
--- /dev/null
+++ b/lib/src/rules/unnecessary_raw_strings.dart
@@ -0,0 +1,57 @@
+// 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'Unnecessary raw string.';
+
+const _details = r'''
+
+Use raw string only when needed.
+
+**BAD:**
+```
+var s1 = r'a';
+```
+
+**GOOD:**
+```
+var s1 = 'a';
+var s2 = r'$a';
+var s3 = r'\a';
+```
+
+''';
+
+class UnnecessaryRawStrings extends LintRule implements NodeLintRule {
+ UnnecessaryRawStrings()
+ : super(
+ name: 'unnecessary_raw_strings',
+ description: _desc,
+ details: _details,
+ group: Group.style);
+
+ @override
+ void registerNodeProcessors(NodeLintRegistry registry,
+ [LinterContext context]) {
+ final visitor = _Visitor(this);
+ registry.addSimpleStringLiteral(this, visitor);
+ }
+}
+
+class _Visitor extends SimpleAstVisitor<void> {
+ final LintRule rule;
+
+ _Visitor(this.rule);
+
+ @override
+ void visitSimpleStringLiteral(SimpleStringLiteral node) {
+ if (node.isRaw && ![r'\', r'$'].any(node.literal.lexeme.contains)) {
+ rule.reportLint(node);
+ }
+ }
+}
diff --git a/test/rules/unnecessary_raw_strings.dart b/test/rules/unnecessary_raw_strings.dart
new file mode 100644
index 0000000..7f3bc8b
--- /dev/null
+++ b/test/rules/unnecessary_raw_strings.dart
@@ -0,0 +1,22 @@
+// 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.
+
+// test w/ `pub run test -N unnecessary_raw_strings`
+
+f(o) {
+ f(r'a b c d');// LINT
+ f(r"a b c d");// LINT
+ f(r'''a b c d''');// LINT
+ f(r"""a b c d""");// LINT
+ // with \
+ f(r'a b c\d');// OK
+ f(r"a b c\d");// OK
+ f(r'''a b c\d''');// OK
+ f(r"""a b c\d""");// OK
+ // with $
+ f(r'a b c$d');// OK
+ f(r"a b c$d");// OK
+ f(r'''a b c$d''');// OK
+ f(r"""a b c$d""");// OK
+}
