Behavior-Driven Design: One Team's Exploration

Behavior-Driven Development

One Team’s Exploration

Behavior-Driven Development

Or…● BDD● Acceptance Test-Driven Development● Specification by Example● ...

What is BDD?

● Focuses on specifying behavior instead of writing tests

● Defines a language for writing behaviors that can be executedo Gherkin - Given-When-Then statements

Why use BDD?

● functional, end-to-end testing● communication

o with product ownero with team members

● documentation● building the right software

What’s wrong with TDD?

● Nothing● Reading unit-tests harder for the business

What tools & processes did we use?

We were building a REST service with Java, so…cucumber-jvm with groovy.● simplified step-definition (vs Java)Given(~'^an order with all details$') {->

@Given("^a vehicle exists$")public void a_vehicle_exists() throws Throwable {

What tools & processes did we use?

● groovy - cucumber-spring integrationo wasn’t strong, but can be worked around

● Could’ve used unit testing directly

Scenario: place a valid order Given an order with all details When an order is placed Then a "CREATED" response is returned And the location of the new order is returned And a confirmation number is returned And the status is "ACTIVE"

def “place a valid order”() { given: “an order with all details” when: “an order is placed” then: “a CREATED response is returned” and: “the location of the new order is returned” and: “a confirmation number is returned” and: “the status is ACTIVE”}

How did it go?

Better Team Communication

Less Assumptions

Clarified assumptions with the Given clauses

Reviews and Unit Testing

Code review focus● Read tests first

Unit test changes● Used the Spock given-when-then structure, often with

comments, to explain the test similar to Cucumber.

Product Owner Involvement

Product Owner never ended up looking at the tests

Story Breakdown

Difficulty with scrum story breakdown and swarming● Starting with Cucumber

feature left us feeling constrained with how the next steps would happen.

● How to get more than two people on it and still feel effective?

Others

More time consuming

Not everyone likes it

What would I do differently?

● Continue working on involving product owner

● Create feature statements as part of story creation

● Demonstrate progress through test report

Summary

● BDD was a good thing● I think we should continue the practice

o though stronger business involvement is needed for it to be truly effective

Questions