Rspec Tutorial

dog.rb

class Dog
  def bark
    "Meow!"
  end
end

dog.spec.rb

require 'rspec'
require_relative 'dog'

describe Dog do
  describe '#bark' do
    it 'returns the string "Woof!"' do
      expect(subject.bark).to eql('Woof!')
    end
  end
end

Gemfile

source 'https://rubygems.org'
gem 'rspec'