Making BDD fun with Ruby and Cucumber

Andrei Marfievici

ContentWhat is BDD?

Why Ruby and Cucumber

Live Demo

Conclusions

What is BDD?Inspired from TDD and complements DDD

It’s NOT unit testing where:Unit test tools are written mainly for developersTests are methods namesIt does a great job for object/module testingIt takes a technical person to understand the

assertions and failuresIt takes a lot of time to gain domain knowledge

What is BDD?Story testing approach

Complex interactions between ALL the people involved in a project

Functionalities trigger the development process

Specs Features Behavior Scenarios

DDD defines the vocabulary (the words) whilst BDD defines the sentences to put the words in

What is BDD?A functionality describes a feature

As a RoleI request a FeatureTo gain a Benefit

Example:Feature: Search for music data

As a Last.fm user I want to be able to search data So that I can listen to my favorite music

Why Ruby and Cucumber?Describe features in plain text through scenarios

Cucumber understands Gherkin language

GWT approach for writing scenarios:Scenario: Basic Search

Given I navigate to http://www.last.fm When I search for “ac/dc” Then I get results back

Why Ruby and Cucumber?Wrap code inside steps

Why Ruby and Cucumber?Can be used as a scripting languagePowerful Lightweight OOP languageSize of the projectMulti-platformEasy to integrate with CI serversGreat support on ruby gemsIRB debugging and on-the-fly developmentA minus for serialization

ConclusionsUnified SDLC through feature filesOutside-in approach

Feature coverage

Brings people together (“help me to help you”)

The power of concrete examples creativity

Great documentation for the projectValidation comes first