How I would start mastermind

mastermind_test.rb

require 'minitest/autorun'
require 'minitest/spec'
require 'minitest/pride'
require 'stringio'


# I *might* wind up with classes like this
class RandomInputGenerator
  def call
    4.times.map { ['R', 'G', 'B', 'Y'].sample }.join
  end
end
class PredeterminedInputGenerator
  def initialize(input)
    @input = input
  end

  def call
    @input
  end
end


class Cli
  class Input
    def initialize(input)
      @input = (input || 'q').chomp.downcase
    end

    def instructions?
      @input == 'i'
    end

    def quit?
      @input == 'q' || @input == 'quit'
    end
  end

  # this *might* take an input_generator,
  # which would either be an instance of RandomInputGenerator or PredeterminedInputGenerator
  def initialize(instream, outstream)
    self.instream, self.outstream = instream, outstream
  end

  def call
    outstream.puts  "Welcome to MASTERMIND"
    outstream.puts  "Would you like to (p)lay, read the (i)nstructions, or (q)uit?"

    loop do
      outstream.print "> "
      input = Input.new(instream.gets)

      if input.instructions?
        outstream.puts 'Instructions: FIXME'
      elsif input.quit?
        outstream.puts 'Goodbye!'
        break
      end
    end
  end

  private

  attr_accessor :instream, :outstream
end



class MastermindTest < Minitest::Spec
  def input_for(input_string)
    StringIO.new(input_string)
  end

  def output_stream
    @output_stream ||= StringIO.new
  end

  it 'prints instructions when I say "i", and quits when I say "q"' do
    mastermind = Cli.new input_for("i\nq\n"), output_stream
    mastermind.call
    assert_match /welcome/i,       output_stream.string
    assert_match /instructions:/i, output_stream.string
    assert_match /goodbye/i,       output_stream.string
  end

  it 'treats inputs as case insensitive' do
    assert Cli::Input.new("q").quit?
    assert Cli::Input.new("Q").quit?
  end

  it 'treats no-input as a quit' do
    assert Cli::Input.new(nil).quit?
  end

  it 'ignores newlines after the input' do
    assert Cli::Input.new("quit").quit?
    assert Cli::Input.new("quit\n").quit?
  end

  it 'treats "q" and "quit" as quit' do
    refute Cli::Input.new("i").quit?
    assert Cli::Input.new("q").quit?
    assert Cli::Input.new("quit").quit?
  end
end