Telling Stories with
RSpec
Rahoul Baruah

Functional Specifications
• Functionality and Features
• Sketches
• Pages and pages of text

Big Design Up Front
• Estimates for cost and delivery dates
• Agreement and sign-off
• Misunderstandings
• Software is Intangible
• Change is inevitable

“Agile” Development
• Short descriptions of each feature
• Testable and Verifiable
• Easy to understand
• Easy to manage
• Easy to prioritise
• Easy to change

RSpec and Behaviour Driven
Development
• Getting the words right
• It should do this
• blue.should be_darker_than(turquoise)
• Code as Specification

Mock Objects
• vat_calculator = mock ‘VAT Calculator’
• invoice.vat_calculator = vat_calculator
• invoice.sub_total = 100
• vat_calculator.should_receive(:calculate).with(100).and_re
turn(17.5)
• invoice.total.should == 117.5

Integration Tests
• Test the full stack
• Interactions between objects
• Written as code

RSpec User Stories
• User Stories
• Full Stack Testing
• Plain Text plus Executables

Story Structure
• As a ...
• I want ...
• So that ...

Scenarios
• Different paths
• Success and Errors
• “Blank Slate”

Given
• Set up pre-requisites
• Set up state
• Given a user called Dave
• And Dave is logged in

When
• Actions performed by the actor
• When I click the ‘profile’ link
• When I enter my new password and confirmation
• And click the ‘Change my password’ button
• Defined in terms of the user interface

Then
• Defines the results of your actions
• Then I should see my profile page
• And it should list how many items I have bought
• Defined in terms of the user interface

Steps
• Given, When and Then
• Text matchers, with parameters
• Executable

Test the Full-Stack
• Specify in terms of User-Interface elements
• Parse the DOM to check for results
• Defines the user interface for the customer

Webrat
When “Dave logs in” do
visit login_path
fill_in ‘User Name’, :with => ‘Dave’
fill_in ‘Password’, :with => ‘secret’
click_button ‘Log In’
end

RSpec Matchers
Then “Dave’s profile page is shown” do
response.should be_success
response.should render_template(‘profiles/show’)
response.should include_text(“Dave’s profile page”)
end

Cucumber
• Structure for organising stories and steps
• rake features
• Is now part of RSpec

Process
• Write a Story
• Write the first step
• Write the specifications for the controllers
• Write the controllers
• Write the specifications for the models
• Write the models
• Run the Story
• Write the next step

References
• RSpec
• Cucumber
• Webrat
• JBehave
• Celerity
• HTMLUnit