animal_class.rb

require 'rspec'

module Flight
  def fly
    puts "I am a #{self.class} and I am flying"
  end
end

class Animal
  def warm_blooded?
    return true
  end
end

class Bird < Animal
  include Flight
end

class Mammal < Animal

end

class Primate < Mammal
  attr_reader :num_legs

  def initialize
    @num_legs = 2
  end
end

class Chimpanzee < Primate

end

class Amphibian < Animal
  def warm_blooded?
    return false
  end
end

class Frog < Amphibian

end

class Bat < Bird

end

class Parrot < Bird

end

test_animals.rb

require './animal_classes.rb'
require 'pp'

describe Animal do
  before do
    @animal = Animal.new
  end

end

describe Frog do
  before do
    @frog = Frog.new
  end

  describe '#warm_blooded?' do
    it 'should return false' do

      result = @frog.warm_blooded?
      expect(result).to eq(false)
    end
  end
end

describe Chimpanzee do
  before do
    @chimp = Chimpanzee.new
  end

  describe '#num_legs' do
    it 'should return 2' do

      result = @chimp.num_legs
      expect(result).to eq(2)
    end
  end

  describe '#warm_blooded?' do
    it 'should return false' do

      result = @chimp.warm_blooded?
      expect(result).to eq(true)
    end
  end
end

describe Parrot do
  before do
    @parrot = Parrot.new
  end

  describe '#fly' do
    it 'should output I am a Parrot and I am flying' do
      expect{@parrot.fly}.to output("I am a Parrot and I am flying").to_stdout
    end
  end
end