StringEscaper: a Ruby class designed to escape literal strings

string-escaper.rb

#!/usr/bin/env ruby

BACKSLASH = '\\'

class StringEscaper
    def initialize chars_to_escape, escaper = BACKSLASH
        # The escaper char must be escaped as well:
        chars_to_escape.push(escaper) unless chars_to_escape.include?(escaper)
        # We escape backslashes as they are the regex escape character:
        regex_content = chars_to_escape.join('|').gsub! '\\', '\\\\\\'

        @regex = /(#{regex_content})/
        @escaper = escaper
    end

    def escape value
        return value.gsub(@regex) { |match| "#{@escaper}#{match}" }
    end
end

# Sample usage:
escaper = StringEscaper.new ['"']
text = 'This is a "test"! /!\\'

puts "UNESCAPED TEXT: #{text}"
puts "ESCAPED TEXT  : #{escaper.escape(text)}"
puts
puts '// Example, desclaring a JS var using the string above:'
puts '// Before:', "var str = \"#{text}\""
puts '// After: ', "var str = \"#{escaper.escape text}\""