A short introduction to BDD (BDD from the eyes of a test-first maniac) by Jakub Zalas Polish Developers Meetup in London 

@jakzal @jakub_zalas @SensioLabsUK £ 

Act 1: Going inside out or how it all started 

Test Driven Development 

Test Driven Development Introducing BDD, Dan North http://dannorth.net/introducing-bdd/ 

Test Driven Development Behaviour Introducing BDD, Dan North http://dannorth.net/introducing-bdd/ 

public class DeliveryRepositoryTest extends TestCase { public void testFindDelivery() { // ... } public void testFindDelivery2() { // ... } } 

public class DeliveryRepositoryTest extends TestCase { public void testFindsDeliveryByTrackingCode() { // ... } public void testFailsForInvalidTrackingCode() { // ... } } DeliveryRepository •  finds delivery by tracking code •  fails for invalidtracking code 

public class DeliveryControllerTest extends WebTestCase { public void testItShowsDeliveryDetailsForAValidTrackingCode() { // ... } public void testItDoesNotShowADeliveryForExpiredTrackingCode() { // ... } public void testItDoesNotShowADeliveryDeliveredMoreThanAMonthAgo() { // ... } } DeliveryController •  it shows delivery details for a valid tracking code •  it does not show a delivery for expired tracking code •  it does not show a delivery delivered more than a month ago 

Act 2: Improving communication or how I thought I got it right 

Customers should be able to sign in! Avatars generated on http://www.customsouthparks.com/ 

1. Open a browser 2. Put the site URL in the browser and press enter 3. Give username 4. Give password 5. Press submit button 6. Check if I gained access to the secured area 

package poldev.controller; public class AuthController { public void signIn() { // ... } } 

Signing in 

As a Customer I want to sign in In order to be signed in 

As a Customer I want to sign in In order to be signed in track my deliveries 

As an Customer Owner I want to sign in In order to be signed in track my deliveries 

As an Customer Owner I want to sign in Customers to sign in In order to be signed in track my their deliveries 

When an anonymous user goes to the deliveries page Then he should see the signin form And he shouldn't see any delivery details 

When a Customer goes to the deliveries page And gives his login details Then he should see a list of his deliveries 

Feature: Tracking deliveries As a Customer I need to see a status of my delivery So I could know when it's going to be delivered 

Feature: Tracking deliveries As a Customer I need to see a status of my delivery So I could know when it's going to be delivered 

Feature: Tracking deliveries As a Customer I need to see a status of my delivery So I could know when it's going to be delivered Scenario: Clicking a tracking URL Scenario: Clicking a tracking URL month after delivery 

Feature: Tracking deliveries As a Customer I need to see a status of my delivery So I could know when it's going to be delivered Scenario: Clicking a tracking URL Given I am waiting for a delivery And I received a confirmation message When I click the tracking URL from the message Then I should see a status of my delivery Scenario: Clicking a tracking URL month after delivery Given I my package was delivered a month ago And I kept the confirmation message When I click the tracking URL from the message Then I should be informed the tracking URL has expired 

Feature: Tracking deliveries As a Customer I need to see a status of my delivery So I could know when it's going to be delivered Scenario: Clicking a tracking URL Given I am waiting for a delivery And I received a confirmation message When I click the tracking URL from the message Then I should see a status of my delivery Scenario: Clicking a tracking URL month after delivery Given I my package was delivered a month ago And I kept the confirmation message When I click the tracking URL from the message Then I should be informed the tracking URL has expired 

Failing step Failing test Code Refactor Passing step External quality Internal quality 

Act 3: Going outside in or focusing on a goal 

"I need Customers to sign into the site to track their delivery." Mr Client 

As a Customer I need to sign into the site So I could track my delivery 

As a Customer I need to see my deliveries So I could know when it's going to be delivered 

WHAT'S THE GOAL? 

THE CLIENT CAME WITH A SOLUTION 

"I need users to sign into the site to track their delivery." "Why?" "So they could see where's their package." "Why?" "What do you mean? They need to track their deliveries." "Yes, but why?" 

"Well, our mission is to offer the most customer friendly courier services. We want to increase the number of satisfied customers." "Aha!" "So they wouldn't get impatient and file complaints when the delivery is delayed." "Why?" "So they could know when is it going to be delivered." "Why?" 

< 5% of customers filing complaints Customers Support Notifications Contact the Customer if delivery is delayed Add expected delivery time to the confirmation message SMS notifications Add a tracking URL to the confirmation message E-mail notifications List of deliveries after signing in Prevent complaints Check delivery status Why? Who? How? What? 

MAKE IMPACTS NOT SOFTWARE Gojko Adžić impactmapping.org 

Thank you! 

Credits •  https://www.flickr.com/photos/hinkelstone/5166544084 •  http://www.customsouthparks.com/ •  http://impactmapping.org •  http://dannorth.net/introducing-bdd/