Behaviour Driven Development with Drupal

Bridging the gap between business and technology

Marcin Pajdzik

Twitter: @Marcin_PajdzikDublin, May 2015

How BDD works?

Write scenarios that describe behaviours

Execute the scenarios against your application.

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How BDD works?

Write each step of your scenarioin plain English.

Write each step definition in PHP.

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NHS - National Health Service

Project started in 2002.

Project terminated in 2010

Cost: €14 400 000 000 (billion)

NHS - National Health Service

€14.4bn would pay a salary of:

60000 nurses for 10 years in the UK

240000 nurses for 10 years in Poland.

NHS - National Health Service

Result: IT system was not FIT for the NHS

Why projects fail?

3. Unrealistic deadlines.

2. Insufficient resource planning.

1. Poor communication.

Source: Computing Technology Industry Association, 2007

Source: Project Management Institute, 2013

What is software development all about?

Delivering BUSINESS VALUE

How do we find out WHAT REALLY MATTERS to the business?

Through effective communication!

What is the problem with communication?

Two people = misunderstandings

Technical and Business = different language

Typical large project = large team, working in a fast-evolving digital domain that no one fully

understands

The main idea behind BDD

Preventing communication gaps

What is BDD?

● Agile methodology based on Test Driven Development

● promotes communication, conversation and close collaboration between everybody in the team

● focuses on writing specification of the system behaviour

Benefits of BDD

3. Business and behaviour first - prioritisation

1. Collaboration / Communication - same language for all

2. Quality – functional / integration / regression tests

4. Documentation

BDD storiesTitle (one line describing the story) Narrative:As a [role]I want [feature]So that [benefit] Acceptance Criteria: (presented as Scenarios)

Scenario 1: TitleGiven [context]When [event]Then [outcome] Scenario 2: ...

BDD stories

As a userI want to loginSo that I can access my account

As a [X]I want [Y]so that [Z]

Scenarios

Given some initial contextWhen an event occurs,Then ensure some outcomes.

Given I am on the login pageWhen I login as “jsmith” with password “secret”Then I should see my account page

Scenarios

●It’s a specification that everybody understands

●It’s a documentation that everybody can refer to

●It’s an automated test that can be run any time

BDD solves TDD shortcomings

Developers want to know:

● where to start

● what to test and what not to test

● how much to test in one go

● what to call their tests

● how to understand why a test fails

Declarative Scenario vs Imperative Scenario

Given I am on the login pageWhen I login as “john” with password “secret”Then I should see my account page

When I go to "user/login"And I enter "john" into the field "username"And I enter "secret" into the field "password"

And I click on the button "login"

Drawbacks

Increases the cost of maintenance

Before doing BDD make sure that there is enough return on investment to justify it.

BDD with Drupal

Behat - allows you to write tests in a human-readable language called Gherkin and parses it into executable test-cases

Mink - web acceptance tests, provides MinkContext with step definitions for interactions with a browser

Drupal Extension - provides Drupal specific functionality

Drupal Extension Drivers

Blackbox Driver

Drupal API Driver

Drush Driver

System Requirements

PHP 5.3.5 or higher with curl, mbstring and xmlJava required for Selenium

Installation

{ "require": { "behat/behat": "2.4.*@stable" }, "minimum-stability": "dev", "config": { "bin-dir": "bin/" }}

$ curl http://getcomposer.org/installer | php

$ php composer.phar install

$ bin/behat

$ mkdir ls_project$ cd ls_project

$ behat --init

Installation

default: paths: features: 'features' extensions: Behat\MinkExtension\Extension: goutte: ~ selenium2: ~ base_url: http://seven.l Drupal\DrupalExtension\Extension: blackbox: ~

Make your FeatureContext.php aware of both the Drupal Extension and the Mink Extension

How to make the scenarios available to everybody?

Behat Jira Extension

Behat Jira Extension {code:none}Feature: Jira integration In order to facilitate the authoring of Behat features by non-developers As a developer I want to write an extension to load features from Jira issues.

Scenario: Load Me! Given I am a Jira issue And I contain a Behat feature When I am loaded by JiraExtension Then I should parsed by Gherkin

{code}

Behat Jira Extension

bin/behat jira:BDD-1

bin/behat http://jira.example.com:8080/browse/BDD-1

BDD in business

“After the decision to move our websites onto Drupal, adopting Behavior Driven Development has been one of the best decisions we’ve made for our organization in years.” Paul Lomax - CTO, Dennis Publishing

References

Dan North & Associates - http://dannorth.net/

Mink - http://mink.behat.org/

Behat - http://behat.org/

DSpeak - http://dspeak.com/drupalextension/intro.html

Marcin Pajdzik

LinkedIn: uk.linkedin.com/in/marcinpajdzik/

Twitter: @Marcin_Pajdzik

Owner / Consultant @ Codewriters Ltd

Thank You