This document describes Neverfails, a tool that automatically generates code to make tests pass without manual coding. It demonstrates Neverfails by walking through how it creates the code needed to pass a Cucumber test for displaying a "No apples left" message. It generates the model, controller, route, and view code step-by-step. At the end, it suggests running Neverfails on another similar test for bananas with a single command.

1. Neverfails:
writes the code to
make your tests pass
(so you don’t have to)
Claudio Baccigalupo
http://github.com/claudiob
Thursday 11 August 2011

2. cukes.info
Thursday 11 August 2011

3. cukes.info
Thursday 11 August 2011

4. github.com/claudiob/neverfails/tree/rails
Thursday 11 August 2011

5. Feature: Apples
Scenario: No apples left
Given there are no apples
When I browse the list of apples
Then I should see the text "No apples left"
+ step definitions
Scenario: No apples left
Given there are no apples
No model found called Apple.
When I browse the list of apples
Then I should see the text "No apples left"
Step 1: Now go and create the model
Thursday 11 August 2011

6. rails g model apple
rake db:migrate
+ step definitions
Scenario: No apples left
Given there are no apples
When I browse the list of apples
No URL pattern found matching /apples.
Then I should see the text "No apples left"
Step 2: Create the controller and the route
Thursday 11 August 2011

7. rails g controller Apples index
sed -i '' '
/get "apples/index"/ a
match "/apples" => "apples#index"
' config/routes.rb
+ step definitions
Scenario: No apples left
Given there are no apples
When I browse the list of apples
Then I should see the text "No apples left"
The text "No apples left" was not found
Step 3: Adapt the view
Thursday 11 August 2011

8. echo "No apples left" >| app/views/apples/
index.html.erb
+ step definitions
Scenario: No apples left
Given there are no apples
When I browse the list of apples
Then I should see the text "No apples left"
Hooray!
Thursday 11 August 2011

9. Feature: Bananas
Scenario: No bananas left
Given there are no bananas
When I browse the list of bananas
Then I should see the text "No bananas left"
Neverfails
Scenario: No bananas left
Given there are no bananas
When I browse the list of bananas
Then I should see the text "No bananas left"
curl http://octo.cat/4j -Ls | bash
Thursday 11 August 2011

10. claudiob@gmail.com
github.com/claudiob
Thursday 11 August 2011