Firehose Card Challenge

card.rb

class Card
  attr_accessor :rank, :suit

  def initialize(rank, suit)
    self.rank = rank
    self.suit = suit
  end

  def output_card
    puts "#{self.rank} of #{self.suit}"
  end

end

class Deck
  attr_accessor :cards

  def cards
    @cards ||= populate_deck
  end

  def initialize
  end

  def ranks
    %w{2 3 4 5 6 7 8 9 10 Jack Queen King Ace}
  end

  def suits
    ['spades', 'clubs', 'hearts', 'diamonds' ]
  end

  def shuffle
    cards.shuffle!
  end

  def deal
    cards.shift
  end

# private
  def populate_deck
    possible_combinations.map do |rank, suit|
      Card.new rank, suit
    end
  end

  def possible_combinations
    @card_combinations ||= ranks.product suits
  end

end

card_spec.rb

require 'rspec_helper'

RSpec.describe Deck do

  it 'returns all possible card combinations' do
    expect(Deck.new.possible_combinations).to eq [
      %w(2 spades), %w(2 clubs), %w(2 hearts), %w(2 diamonds),
      %w(3 spades), %w(3 clubs), %w(3 hearts), %w(3 diamonds),
      %w(4 spades), %w(4 clubs), %w(4 hearts), %w(4 diamonds),
      %w(5 spades), %w(5 clubs), %w(5 hearts), %w(5 diamonds),
      %w(6 spades), %w(6 clubs), %w(6 hearts), %w(6 diamonds),
      %w(7 spades), %w(7 clubs), %w(7 hearts), %w(7 diamonds),
      %w(8 spades), %w(8 clubs), %w(8 hearts), %w(8 diamonds),
      %w(9 spades), %w(9 clubs), %w(9 hearts), %w(9 diamonds),
      %w(10 spades), %w(10 clubs), %w(10 hearts), %w(10 diamonds),
      %w(Jack spades), %w(Jack clubs), %w(Jack hearts), %w(Jack diamonds),
      %w(Queen spades), %w(Queen clubs), %w(Queen hearts), %w(Queen diamonds),
      %w(King spades), %w(King clubs), %w(King hearts), %w(King diamonds),
      %w(Ace spades), %w(Ace clubs), %w(Ace hearts), %w(Ace diamonds)
    ]
  end

  it 'has 52 cards' do
    expect(Deck.new.cards.size).to eq 52
  end

  it 'has 13 ranks' do
    expect(Deck.new.ranks.size).to eq  13
  end

  it 'has 4 suits' do
    expect(Deck.new.suits.size).to eq 4
  end

  describe '#deal' do

    let(:deck) { Deck.new }
    it 'can deal a card' do
      expect { deck.deal }.to change {
        deck.cards
      }
    end

    it 'reduces the amount of cards' do
      expect { deck.deal }.to change {
        deck.cards.size
      }.from(52).to(51)
    end

    it 'can deal more than 52 cards' do
      52.times { deck.deal }

      expect { deck.deal }.not_to raise_exception
    end

    it 'returns a card' do
      expect(deck.deal).to be_kind_of Card
    end
  end
end

rspec_helper.rb

require_relative 'card'
require 'rspec'

# gem install rspec

run.rb

require_relative 'card'

deck = Deck.new
deck.deal
deck.deal.output_card

test.rb

require_relative 'card'

puts 'possible combinations '
puts Deck.new.possible_combinations == [
  %w(2 spades), %w(2 clubs), %w(2 hearts), %w(2 diamonds),
  %w(3 spades), %w(3 clubs), %w(3 hearts), %w(3 diamonds),
  %w(4 spades), %w(4 clubs), %w(4 hearts), %w(4 diamonds),
  %w(5 spades), %w(5 clubs), %w(5 hearts), %w(5 diamonds),
  %w(6 spades), %w(6 clubs), %w(6 hearts), %w(6 diamonds),
  %w(7 spades), %w(7 clubs), %w(7 hearts), %w(7 diamonds),
  %w(8 spades), %w(8 clubs), %w(8 hearts), %w(8 diamonds),
  %w(9 spades), %w(9 clubs), %w(9 hearts), %w(9 diamonds),
  %w(10 spades), %w(10 clubs), %w(10 hearts), %w(10 diamonds),
  %w(Jack spades), %w(Jack clubs), %w(Jack hearts), %w(Jack diamonds),
  %w(Queen spades), %w(Queen clubs), %w(Queen hearts), %w(Queen diamonds),
  %w(King spades), %w(King clubs), %w(King hearts), %w(King diamonds),
  %w(Ace spades), %w(Ace clubs), %w(Ace hearts), %w(Ace diamonds)
]
puts 'cards should be 52'
puts Deck.new.cards.size == 52
puts 'should have 13 ranks'
puts Deck.new.ranks.size == 13
puts 'should have 4 suits'
puts Deck.new.suits.size == 4

puts 'testing dealing'
deck = Deck.new
before_dealing = deck.cards.join
deck.deal
after_dealing = deck.cards.join

puts before_dealing != after_dealing