Enable raw strings lint rules (#418) * Enable use_raw_strings lint rule * Enable unnecessary_raw_strings lint rule Co-authored-by: Sam Rawlins <srawlins@google.com>

diff --git a/analysis_options.yaml b/analysis_options.yaml
index 18598d8..92ca266 100644
--- a/analysis_options.yaml
+++ b/analysis_options.yaml

@@ -33,4 +33,6 @@
     - throw_in_finally
     - prefer_final_locals
     - use_if_null_to_convert_nulls_to_bools
+    - use_raw_strings
+    - unnecessary_raw_strings
     - prefer_interpolation_to_compose_strings

diff --git a/example/app.dart b/example/app.dart
index f9556c2..78da8a3 100644
--- a/example/app.dart
+++ b/example/app.dart

@@ -14,7 +14,7 @@
 
 final nullSanitizer = NullTreeSanitizer();
 const typing = Duration(milliseconds: 150);
-final introText = r'''Markdown is the **best**!
+final introText = '''Markdown is the **best**!
 
 * It has lists.
 * It has [links](https://dart.dev).

diff --git a/lib/src/block_parser.dart b/lib/src/block_parser.dart
index b54fce7..17a7739 100644
--- a/lib/src/block_parser.dart
+++ b/lib/src/block_parser.dart

@@ -88,9 +88,9 @@
     LongBlockHtmlSyntax(r'^ {0,3}<script(?:\s|>|$)', '</script>'),
     LongBlockHtmlSyntax(r'^ {0,3}<style(?:\s|>|$)', '</style>'),
     LongBlockHtmlSyntax('^ {0,3}<!--', '-->'),
-    LongBlockHtmlSyntax('^ {0,3}<\\?', '\\?>'),
+    LongBlockHtmlSyntax(r'^ {0,3}<\?', r'\?>'),
     LongBlockHtmlSyntax('^ {0,3}<![A-Z]', '>'),
-    LongBlockHtmlSyntax('^ {0,3}<!\\[CDATA\\[', '\\]\\]>'),
+    LongBlockHtmlSyntax(r'^ {0,3}<!\[CDATA\[', r'\]\]>'),
     const OtherTagBlockHtmlSyntax(),
     const SetextHeaderSyntax(),
     const HeaderSyntax(),
@@ -211,7 +211,7 @@
       element.children!.first.textContent
           .toLowerCase()
           .trim()
-          .replaceAll(RegExp(r'[^a-z0-9 _-]'), '')
+          .replaceAll(RegExp('[^a-z0-9 _-]'), '')
           .replaceAll(RegExp(r'\s'), '-');
 }
 
@@ -591,19 +591,19 @@
 
 class BlockTagBlockHtmlSyntax extends BlockHtmlSyntax {
   static final _pattern = RegExp(
-      r'^ {0,3}</?(?:address|article|aside|base|basefont|blockquote|body|'
-      r'caption|center|col|colgroup|dd|details|dialog|dir|div|dl|dt|fieldset|'
-      r'figcaption|figure|footer|form|frame|frameset|h1|head|header|hr|html|'
-      r'iframe|legend|li|link|main|menu|menuitem|meta|nav|noframes|ol|optgroup|'
-      r'option|p|param|section|source|summary|table|tbody|td|tfoot|th|thead|'
-      r'title|tr|track|ul)'
+      '^ {0,3}</?(?:address|article|aside|base|basefont|blockquote|body|'
+      'caption|center|col|colgroup|dd|details|dialog|dir|div|dl|dt|fieldset|'
+      'figcaption|figure|footer|form|frame|frameset|h1|head|header|hr|html|'
+      'iframe|legend|li|link|main|menu|menuitem|meta|nav|noframes|ol|optgroup|'
+      'option|p|param|section|source|summary|table|tbody|td|tfoot|th|thead|'
+      'title|tr|track|ul)'
       r'(?:\s|>|/>|$)');
 
   /// The [_pattern] regular expression above is very expensive, even on
   /// paragraphs of Markdown with no HTML. This regular expression can be used
   /// first as a basic check that the input might possibly be an HTML block
   /// tag, which occur very rarely in typical Markdown.
-  static final _openBracketPattern = RegExp(r'^ {0,3}<');
+  static final _openBracketPattern = RegExp('^ {0,3}<');
 
   @override
   RegExp get pattern => _pattern;
@@ -1238,7 +1238,7 @@
   bool _parseReflinkDefinition(BlockParser parser, String contents) {
     final pattern = RegExp(
         // Leading indentation.
-        r'''^[ ]{0,3}'''
+        '''^[ ]{0,3}'''
         // Reference id in brackets, and URL.
         r'''\[((?:\\\]|[^\]])+)\]:\s*(?:<(\S+)>|(\S+))\s*'''
         // Title in double or single quotes, or parens.

diff --git a/lib/src/inline_parser.dart b/lib/src/inline_parser.dart
index 29b09b3..ac0cc73 100644
--- a/lib/src/inline_parser.dart
+++ b/lib/src/inline_parser.dart

@@ -22,7 +22,7 @@
     // "*" surrounded by spaces is left alone.
     TextSyntax(r' \* ', startCharacter: $space),
     // "_" surrounded by spaces is left alone.
-    TextSyntax(r' _ ', startCharacter: $space),
+    TextSyntax(' _ ', startCharacter: $space),
     // Parse "**strong**" and "*emphasis*" tags.
     EmphasisSyntax.asterisk(),
     // Parse "__strong__" and "_emphasis_" tags.
@@ -35,13 +35,13 @@
       List<InlineSyntax>.unmodifiable(<InlineSyntax>[
     // Leave already-encoded HTML entities alone. Ensures we don't turn
     // "&amp;" into "&amp;amp;"
-    TextSyntax(r'&[#a-zA-Z0-9]*;', startCharacter: $ampersand),
+    TextSyntax('&[#a-zA-Z0-9]*;', startCharacter: $ampersand),
     // Encode "&".
-    TextSyntax(r'&', sub: '&amp;', startCharacter: $ampersand),
+    TextSyntax('&', sub: '&amp;', startCharacter: $ampersand),
     // Encode "<".
-    TextSyntax(r'<', sub: '&lt;', startCharacter: $lt),
+    TextSyntax('<', sub: '&lt;', startCharacter: $lt),
     // Encode ">".
-    TextSyntax(r'>', sub: '&gt;', startCharacter: $gt),
+    TextSyntax('>', sub: '&gt;', startCharacter: $gt),
   ]);
 
   /// The string of Markdown being parsed.
@@ -549,7 +549,7 @@
 
   // Trailing punctuation (specifically, ?, !, ., ,, :, *, _, and ~) will not
   // be considered part of the autolink
-  static const truncatingPunctuationPositive = r'[?!.,:*_~]';
+  static const truncatingPunctuationPositive = '[?!.,:*_~]';
 
   static final regExpTrailingPunc = RegExp('$truncatingPunctuationPositive*\$');
   static final regExpEndsWithColon = RegExp(r'\&[a-zA-Z0-9]+;$');
@@ -742,7 +742,7 @@
   // This RegExp is inspired by
   // https://github.com/commonmark/commonmark.js/blob/1f7d09099c20d7861a674674a5a88733f55ff729/lib/inlines.js#L39.
   // I don't know if there is any way to simplify it or maintain it.
-  static final RegExp punctuation = RegExp(r'['
+  static final RegExp punctuation = RegExp('['
       r'''!"#$%&'()*+,\-./:;<=>?@\[\]\\^_`{|}~'''
       r'\xA1\xA7\xAB\xB6\xB7\xBB\xBF\u037E\u0387\u055A-\u055F\u0589\u058A\u05BE'
       r'\u05C0\u05C3\u05C6\u05F3\u05F4\u0609\u060A\u060C\u060D\u061B\u061E'

diff --git a/test/blns.dart b/test/blns.dart
index f059f6d..a649c3a 100644
--- a/test/blns.dart
+++ b/test/blns.dart

@@ -2,9 +2,9 @@
 //
 // This file was generated from big-list-of-naughty-strings's JSON file:
 // https://github.com/minimaxir/big-list-of-naughty-strings/raw/master/blns.json
-// at 2021-11-14 15:03:54.726971 by the script, tool/update_blns.dart.
+// at 2022-04-16 22:37:54.467197 by the script, tool/update_blns.dart.
 
-// ignore_for_file: text_direction_code_point_in_literal
+// ignore_for_file: text_direction_code_point_in_literal, use_raw_strings
 
 const blns = <String>[
   '',

diff --git a/test/markdown_test.dart b/test/markdown_test.dart
index 539c397..827a696 100644
--- a/test/markdown_test.dart
+++ b/test/markdown_test.dart

@@ -106,7 +106,7 @@
 
     validateCore(
         'can choose to _not_ resolve something, like an empty link',
-        r'''
+        '''
 resolve [[]] thing
 ''',
         '''

diff --git a/tool/stats.dart b/tool/stats.dart
index 55ec4ca..55f05b8 100644
--- a/tool/stats.dart
+++ b/tool/stats.dart

@@ -81,7 +81,7 @@
   }
 }
 
-final _sectionNameReplace = RegExp('[ \\)\\(]+');
+final _sectionNameReplace = RegExp(r'[ \)\(]+');
 
 String _unitOutput(Iterable<DataCase> cases) => cases.map((dataCase) => '''
 >>> ${dataCase.front_matter}

diff --git a/tool/update_blns.dart b/tool/update_blns.dart
index 589b52f..7491470 100644
--- a/tool/update_blns.dart
+++ b/tool/update_blns.dart

@@ -27,7 +27,7 @@
 // $_blnsJsonRawUrl
 // at ${DateTime.now()} by the script, tool/update_blns.dart.
 
-// ignore_for_file: text_direction_code_point_in_literal
+// ignore_for_file: text_direction_code_point_in_literal, use_raw_strings
 
 ''');
   blnsContent.writeln('const blns = <String>[');