Cucumber, PhantomJS, and

SeleniumDustin Barnes

Solutions Architect

Cucumber• Behavior-driven development (BDD)• Originally a Ruby project• Cucumber-jvm for Java projects• Language called Gherkin• Natural-language specification

BDD• Alternative to TDD• Response to issues with TDD:– Where to start in process?– What to test and what not to test?– How much to test at once– What to call the tests– Understand why a test fails

• Specifies the *behavior* of your unit.

Why BDD?• PM/BA write cucumber features– Test first!– Easy when test == spec

• Developers write step definitions

Cucumber Nomenclature• Feature – Single file, ideally

describing a single feature• Scenario – A test case• Given-When-Then: Test preconditions,

execution, and postconditions• And, But – Additional test constructs

Cucumber Example

Cucumber Step Definitions

Cucumber Parameterization

Cucumber Step Definitions

Details, details…• Doesn’t need to be frontend-based• Can use TestNG, JUnit, etc. • You write all the step details• Compose steps for more powerful

statements

Selenium• Does it even need an introduction? • Browser driver for acceptance tests• Requires a real browser

Selenium

Selenium + Cucumber

Continuous Integration• Selenium WebDriver requires a browser• Your CI server probably doesn’t have

Chrome or Firefox installed– Or even a GUI…

• How can we run these tests without setting up a remote runner or selenium grid?

PhantomJS• PhantomJS to the rescue!• Headless WebKit browser• Scriptable through JavaScript• Now a PhantomJS Driver in

WebDriver

PhantomJS

PhantomJS Driver

Demo• We’ve offered 4 PMs as sacrifice to

the demo gods…

• Project available on the dev9 GitHub– https://github.com/dev9com/cucumber-java-selenium-example

What have we done?• Textual language description of tests• As frontend-driven acceptance tests–Written by PM/BA…?

• Running on every commit on our CI server

Gotchas• PhantomJS cannot test browser quirks– Use a separate test suite just for browser-

specific testing. Manual, or with BrowserStack. – Usually <10% of issues need specific browser

testing

• Textual language may give people a false sense of security– Only as strong as the step definitions

Q&A