preprocess.rb in rubocop-md-0.3.0

- old
+ new

@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 require "ripper"
 
 module RuboCop
   module Markdown
     # Transform source Markdown file into valid Ruby file
@@ -8,13 +10,13 @@
       # This is a regexp to extract code blocks from .md files.
       #
       # Only recognizes backticks-style code blocks.
       #
       # Try it: http://rubular.com/r/iJaKBkSrrT
-      MD_REGEXP = /^([ \t]*`{3,4})([\w[[:blank:]]]*\n)([\s\S]+?)(^[ \t]*\1[[:blank:]]*\n?)/m
+      MD_REGEXP = /^([ \t]*`{3,4})([\w[[:blank:]]]*\n)([\s\S]+?)(^[ \t]*\1[[:blank:]]*\n?)/m.freeze
 
-      MARKER = "<--rubocop/md-->".freeze
+      MARKER = "<--rubocop/md-->"
 
       # See https://github.com/github/linguist/blob/v5.3.3/lib/linguist/languages.yml#L3925
       RUBY_TYPES = %w[
         ruby
         jruby
@@ -105,25 +107,27 @@
       # Try to parse with Ripper
       # Invalid Ruby code (or non-Ruby) returns `nil`.
       # Return true if it's explicit Ruby and warn_invalid?
       def valid_syntax?(syntax, src)
         return true if ruby?(syntax) && warn_invalid?
+
         !Ripper.sexp(src).nil?
       end
 
       # Whether to show warning when snippet is not a valid Ruby
       def warn_invalid?
-        config["Markdown"] && config["Markdown"].fetch("WarnInvalid", true)
+        config["Markdown"]&.fetch("WarnInvalid", true)
       end
 
       # Whether to try to detect Ruby by parsing codeblock.
       # If it's set to false we lint only implicitly specified Ruby blocks.
       def autodetect?
-        config["Markdown"] && config["Markdown"].fetch("Autodetect", true)
+        config["Markdown"]&.fetch("Autodetect", true)
       end
 
       def comment_lines!(src)
         return if src =~ /\A\n\z/
+
         src.gsub!(/^(.)/m, "##{MARKER}\\1")
       end
     end
   end
 end