Getting started

Prerequisites

• Ruby 1.8.7 or higher (2.0+ recommended)

Install

gem install rspec

This installs five gems:

• rspec
• rspec-core
• rspec-expectations
• rspec-mocks
• rspec-support

The rspec-core gem installs an rspec executable. Run the rspec command with
the --help flag to see the available options:

rspec --help

Getting started

Begin with a very simple example that expresses some basic desired behaviour.

# game_spec.rb

RSpec.describe Game do
  describe "#score" do
    it "returns 0 for an all gutter game" do
      game = Game.new
      20.times { game.roll(0) }
      expect(game.score).to eq(0)
    end
  end
end

Run the example and watch it fail.

$ rspec game_spec.rb 
  uninitialized constant Object::Game (NameError)

Now write just enough code to make it pass.

# game_spec.rb

require './game'
...

# game.rb

class Game
  def roll(pins)
  end

  def score
    0
  end
end

Run the example and bask in the joy that is green.

$ rspec game_spec.rb --color --format doc

Game
  #score
    returns 0 for all gutter game

Finished in 0.00057 seconds
1 example, 0 failures

Last published about 8 years ago by myronmarston.