animal.rb

class Animal
  SPECIES = ["lion", "elephant"]

  attr_reader :name

  def initialize(name)
    @name = name
  end

  def self.phyla
    %w[Deuterostomia Ecdysozoa Lophotrochozoa Radiata]
  end

  def eat(food)
    "#{name} eats #{food}"
  end

  def self.species
    "hello"
  end

end

puts Animal.species
puts Animal::SPECIES

interface.rb

require_relative 'lion'
require_relative 'meerkat'
require_relative 'warthog'

animals = []

animals << Lion.new("Simba")
animals << Meerkat.new("Timon")
animals << Warthog.new("Pumba")

puts "The animals of the jungle roar"

animals.each do |animal|
  p animal.talk
end

# Another way of writing the above iteration

# animals.each(&:talk)

lion.rb

require_relative "animal"

class Lion < Animal

  def talk
    "#{name} roars"
  end

  def eat(food)
    "#{super(food)}. Law of the jungle!"
  end

end

meerkat.rb

require_relative 'animal'

class Meerkat < Animal
  def talk
    "#{name} tries to sell you car insurance"
  end
end

spec.rb

require_relative '../animal'
require_relative '../lion'
require_relative '../meerkat'

describe Meerkat do
  describe "#eat" do
    it "return a sentence about what the animal is eating" do
      animal = Meerkat.new("timon")
      sentence = animal.eat("a grub")
      expect(sentence).to eq("timon eats a grub")
    end
  end
end


describe Lion do
  describe "#talk" do
    it "returns a sentence stating the lion is roaring" do
      sentence = Lion.new("Simba").talk
      expect(sentence).to eq("Simba roars")
    end
  end

  describe "#eat" do
    it "return a sentence about what the animal is eating" do
      animal = Lion.new("simba")
      sentence = animal.eat("a gazelle")
      expect(sentence).to eq("simba eats a gazelle. Law of the jungle!")
    end
  end

end


describe Animal do
  describe "#initialize" do
    it "creates an Animal instance" do
      animal = Animal.new("babe")
      expect(animal).to be_an(Animal)
    end
  end

  describe "#name" do
    it "should return the name of the animal" do
      name = Animal.new("babe").name
      expect(name).to eq("babe")
    end
  end

  describe "::phyla" do
    it "returns a list of all the different aniomal species" do
      phyla = Animal.phyla
      expect(phyla.length).to eq(4)
    end
  end

  describe "#eat" do
    it "return a sentence about what the animal is eating" do
      animal = Animal.new("babe")
      sentence = animal.eat("a carrot")
      expect(sentence).to eq("babe eats a carrot")
    end
  end

end

warthog.rb

require_relative 'animal'

class Meerkat < Animal
  def talk
    "#{name} tries to sell you car insurance"
  end
end