Poly Driver: A Phantom Band-Aid for Geb

The Problem:

You have an extensive suite of Geb functional tests running against Firefox and it takes a long time to run. You switch your tests over to PhantomJS; now they run twice as fast!

But five percent of the tests intermittently fail. After spending a few hours trying to figure it out, you still don’t know why they are failing — just that they fail sometimes, and you don’t want to spend the next week trying to figure out a workaround. As it stands, it’s not practical to switch to PhantomJS at this time.

A Solution:

Why not use both? Add the Poly Driver plugin to your project and configure it in GebConfig.groovy:

driver = {

   FirefoxDriver firefoxDriver = new FirefoxDriver()
   PhantomJSDriver phantomJSDriver = getPhantomDriver()

   new PolyDriver(mainDriver: phantomJSDriver, alternateDrivers: ['firefox' : firefoxDriver])

private PhantomJSDriver getPhantomDriver() {
   // see Tomás Lin’s excellent blog post on configuring drivers for Geb:
   // http://fbflex.wordpress.com/2013/03/18/how-to-configure-webdriver-in-grails-for-your-geb-tests/

Change the class inheritance of your problem test and annotate it:

class MyGebSpecCase extends GebReportingSpec {


import com.polydriver.spec.PolyDriverGebReportingSpec

class MyGebSpecCase extends PolyDriverGebReportingSpec {

When you run your tests, you will see a Firefox window open but only the FooGebSpecCase (and any others with the @PreferredDriver(‘firefox’) annotation) will use it. The rest of your tests will run quickly in PhantomJS.

The driver allows you to specify as many drivers as you want — you can even declare multiple instances of the same browser, so if you want to run a subset of tests against different Firefox profiles, you can do that:

driver = {
   FirefoxDriver firefoxDriver = new FirefoxDriver()
   FirefoxProfile ffProfile = new FirefoxProfile()
   // setup the other profile
   FirefoxDriver altFirefoxDriver = new FirefoxDriver(ffProfile)
   PhantomJSDriver phantomJSDriver = getPhantomDriver()

   new PolyDriver(
         mainDriver:       phantomJSDriver, 
         alternateDrivers: [
               'firefox':  firefoxDriver, 
               'ff-alt':   altFirefoxDrive

Hopefully this eases the pain of transitioning your test suites to PhantomJS.

About the Author

Object Partners profile.
Leave a Reply

Your email address will not be published. Required fields are marked *

Related Blog Posts
Using Conftest to Validate Configuration Files
Conftest is a utility within the Open Policy Agent ecosystem that helps simplify writing validation tests against configuration files. In a previous blog post, I wrote about using the Open Policy Agent utility directly to […]
SwiftGen with Image & Color Asset Catalogs
You might remember back in 2015 when iOS 9 was introduced, and we were finally given a way to manage all of our assets in one place with Asset Catalogs. A few years later, support […]
Tracking Original URL Through Authentication
If you read my other post about refreshing AWS tokens, then you probably have a use case for keeping track of the original requested resource while the user goes through authentication so you can route […]
Using Spring Beans in a Kafka Streams ExceptionHandler
There are many things to know before diving into Kafka Streams. If you haven’t already, check out these 5 things as a starting point. Bullet 2 mentions designing for exceptions. Ironically, this seems to be […]