ruby-quiz-2024-solver.rb

# Solver for https://ruby-quiz-2024.storesinc.tech/

require 'tempfile'

def solve(number, quiz_src, expected_error)
  threads = []
  answers = {}
  Tempfile.create("temperror_#{number}") do |error_file|
    quiz_src.size.times do |i|
      threads << Thread.start do
        Tempfile.create("#{error_file.path}_#{i}.rb") do |modified_quiz_file|
          modified_quiz_file.write "#{quiz_src[..-(i+1)]}#{quiz_src[(quiz_src.size-i+1)..]}"
          modified_quiz_file.flush

          success = system("ruby #{modified_quiz_file.path} 2>#{error_file.path}")
          if !success && File.read(error_file).include?(expected_error)
            p 'resolved!' + '-' * 100
            puts(answers[i] = File.read(modified_quiz_file))
            File.write("#{number}_answer.rb", answers.values.join("\n"))
            p 'resolved!' + '-' * 100
          end
        end

        (["\n"]+(' '..'~').to_a).each do |char|
          Tempfile.create("#{error_file.path}_#{i}#{char}.rb") do |modified_quiz_file|
            modified_quiz_file.write "#{quiz_src[..i]}#{char}#{quiz_src[i+1..]}"
            modified_quiz_file.flush

            success = system("ruby #{modified_quiz_file.path} 2>#{error_file.path}")
            if !success && File.read(error_file).include?(expected_error)
              p 'resolved!' + '-' * 100
              puts(answers["#{i}#{char}"] = File.read(modified_quiz_file))
              File.write("#{number}_answer.rb", answers.values.join("\n"))
              p 'resolved!' + '-' * 100
            end
          end
        end
      end
    end
  end

  threads.each(&:join)
end

if ARGV[0]
  quiz_src = File.read("#{ARGV[0]}_quiz.rb")
  expected_error = File.read("#{ARGV[0]}_error.rb")
  solve(ARGV[0], quiz_src, expected_error)
else
  %w[1 2 3 4 5 6 7 8 9 a b c].each do |number|
    quiz_src = File.read("#{number}_quiz.rb")
    expected_error = File.read("#{number}_error.rb")
    solve(number, quiz_src, expected_error)
  end
end