[Fix rubocop#12985] Fix an error for `Style/RedundantRegexpCharacterC…

…lass`

Fixes rubocop#12985.

This PR fixes an error for `Style/RedundantRegexpCharacterClass`
when using regexp_parser gem 2.3.1 or older.

This issue has already been resolved in regexp_parser gem 2.4.

In the past, there was an issue with compatibility with regexp_parser 1.x due to the following:
rubocop#9102 (comment)

Currently, many dependent gems including Capybara have permitted upgrading to regexp_parser 2.x:
https://rubygems.org/gems/regexp_parser/reverse_dependencies

Therefore, it would be a good time to specify `spec.runtime_dependency` as regexp_parser 2.4+.

changelog/fix_an_error_for_style_redundant_regexp_character_class.md

@@ -0,0 +1 @@
+* [#12985](https://github.com/rubocop/rubocop/issues/12985): Fix an error for `Style/RedundantRegexpCharacterClass` when using regexp_parser gem 2.3.1 or older. ([@koic][])

lib/rubocop/ext/regexp_parser.rb

@@ -22,26 +22,9 @@ module Expression
         module Base
           attr_accessor :origin
 
-          if Gem::Version.new(Regexp::Parser::VERSION) >= Gem::Version.new('2.0')
-            # Shortcut to `loc.expression`
-            def expression
-              @expression ||= origin.adjust(begin_pos: ts, end_pos: ts + full_length)
-            end
-          # Please remove this `else` branch when support for regexp_parser 1.8 will be dropped.
-          # It's for compatibility with regexp_parser 1.8 and will never be maintained.
-          else
-            attr_accessor :source
-
-            def start_index
-              # ts is a byte index; convert it to a character index
-              @start_index ||= source.byteslice(0, ts).length
-            end
-
-            # Shortcut to `loc.expression`
-            def expression
-              end_pos = start_index + full_length
-              @expression ||= origin.adjust(begin_pos: start_index, end_pos: end_pos)
-            end
+          # Shortcut to `loc.expression`
+          def expression
+            @expression ||= origin.adjust(begin_pos: ts, end_pos: ts + full_length)
           end
 
           # @returns a location map like `parser` does, with:
@@ -69,8 +52,8 @@ def build_location
 
             body = expression.adjust(end_pos: -q.text.length)
             q.origin = origin
-            q.source = source if q.respond_to?(:source=) # for regexp_parser 1.8
             q_loc = q.expression
+
             { body: body, quantifier: q_loc }
           end
         end

rubocop.gemspec

@@ -36,7 +36,7 @@ Gem::Specification.new do |s|
   s.add_runtime_dependency('parallel', '~> 1.10')
   s.add_runtime_dependency('parser', '>= 3.3.0.2')
   s.add_runtime_dependency('rainbow', '>= 2.2.2', '< 4.0')
-  s.add_runtime_dependency('regexp_parser', '>= 1.8', '< 3.0')
+  s.add_runtime_dependency('regexp_parser', '>= 2.4', '< 3.0')
   s.add_runtime_dependency('rexml', '>= 3.2.5', '< 4.0')
   s.add_runtime_dependency('rubocop-ast', '>= 1.31.1', '< 2.0')
   s.add_runtime_dependency('ruby-progressbar', '~> 1.7')