Functional tests for Grails with Geb and geckodriver

Previously we had many functional tests using the selenium-rc plugin for Grails. Many were initially recorded using Selenium IDE, then refactored to be more maintainable. These refactorings introduced “driver” objects used to interact with common elements on the pages and runners which improved the API for walking through a multipage process.

Selenium-rc got deprecated quite a while ago and support for Firefox broke every once in a while. Finally we were forced to migrate to the current state-of-the-art in Grails functional testing: Geb.

Generally I can say it is really a major improvement over the old selenium API. The page concept is similar to our own drivers with some nice features:

  • At-Checkers provide a standardized way of checking if we are at the expected page
  • Default and custom per page timeouts using atCheckWaiting
  • Specification of relevant content elements using a JQuery-like syntax and support for CSS-selectors
  • The so-called modules ease the interaction with form elements and the like
  • Much better error messages

While Geb is a real improvement over selenium it comes with some quirks. Here are some advice that may help you in successfully using geb in the context of your (grails) webapplication.

Cross-plattform testing in Grails

Geb (or more specifically the underlying webdriver component) requires a geckodriver-binary to work correctly with Firefox. This binary is naturally platform-dependent. We have a setup with mostly Windows machines for the developers and Linux build slaves and target systems. So we need binaries for all required platforms and have to configure them accordingly. We have simply put them into a folder in our project and added following configuration to the test-environment in Config.groovy:

environments {
  test {
    def basedir = new File(new File('.', 'infrastructure'), 'testing')
    def geckodriver = 'geckodriver'
    if ([''].toLowerCase().contains('windows')) {
      geckodriver += '.exe'
    System.setProperty('webdriver.gecko.driver', new File(basedir, geckodriver).canonicalPath)

Problems with File-Uploads

If you are plagued with file uploads not working it may be a Problem with certain Firefox versions. Even though the fix has landed in Firefox 56 I want to add the workaround if you still experience problems. Add The following to your GebConfig.grooy:

driver = {
  FirefoxProfile profile = new FirefoxProfile()
  // Workaround for issue
  profile.setPreference('dom.file.createInChild', true)
  new FirefoxDriver(profile)

Minor drawbacks

While the Geb-DSL is quite readable and allows concise tests the IDE-support is not there. You do not get much code assist when writing the tests and calling functions of the page objects like in our own, code based solution.


After taking the first few hurdles writing new functional tests with Geb really feels good and is a breeze compared to our old selenium tests. Converting them will be a lot work and only happen on a case-by-case basis but our coverage with Geb is ever increasing.

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