The RSpec Book

This is documentation for RSpec-1.

For RSpec-2, please see

We will eventually point directly to the rspec 2, but we want to support old links from books and blogs. If you’re interested in volunteering to write an app to manage redirects, please contact


RSpec is a Behaviour-Driven Development tool for Ruby programmers. BDD is an approach to software development that combines Test-Driven Development, Domain Driven Design, and Acceptance Test-Driven Planning. RSpec helps you do the TDD part of that equation, focusing on the documentation and design aspects of TDD.

The RSpec Book

The RSpec Book will introduce you to RSpec, Cucumber, and a number of other tools that make up the Ruby BDD family. Replete with tutorials and practical examples, the RSpec Book will help you get your BDD on, taking you from executable requirements to working software that is clean, well tested, well documented, flexible and highly maintainable.

More information


Cucumber features


Get Started Now

$ gem install rspec

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

# bowling_spec.rb
require 'bowling'

describe Bowling, "#score" do
  it "returns 0 for all gutter game" do
    bowling =
    20.times { bowling.hit(0) }
    bowling.score.should == 0

Run the example and watch it fail.

# rspec-2
$ rspec bowling_spec.rb

# rspec-1
$ spec bowling_spec.rb 

  uninitialized constant Bowling

Now write just enough code to make it pass.

# bowling.rb
class Bowling
  def hit(pins)

  def score

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

# rspec-2
$ rspec bowling_spec.rb --format nested

# rspec-1
$ spec bowling_spec.rb --format nested

  returns 0 for all gutter game

Finished in 0.007534 seconds

1 example, 0 failures

Take very small steps

Don’t rush ahead with more code. Instead, add another example and let it guide you to what you have to do next. And don’t forget to take time to refactor your code before it gets messy. You should keep your code clean at every step of the way.

Take the first step now!