How to provoke Selenium focus issues in parallel test processes

As attachments to this card you will find a Cucumber feature and supplementing step definition that you can use to provoke Selenium focus issues that only occur when two focus-sensitive Selenium scenarios run at the same time (probably with parallel_tests Show archive.org snapshot ). This can help you to detect and fix flickering integration tests.

The attached feature works by going to your root_path and focusing a random form element every 5ms.

Instruction:

• Copy the attached feature and step definition into your project.
• If required, adjust the duration for which concurrency issues are provoked by editing focus_issues.feature (you'll see). Default is 5 minutes. It should be longer than your flickering tests take to run.
• Make sure that your root_path contains a form element (select, input) or edit the step definition to visit another path.
• Comment out non-flickering scenarios in your feature that contains flickering tests. The problematic feature should ideally only contain flickering Selenium-scenarios.
• Run the feature together with the feature that contains flickering tests, e.g. with Geordi Show archive.org snapshot : cuc features/focus_issues.feature features/flickering_tests.feature
• Be careful not to use a line number in the call. Tests will not run in parallel when a line number is used.
• Observe how each test process now spawns a separate Firefox window (if you are using Geordi support for headless Selenium with VNC you need to call cuc-show to see the Firefoxes). Make sure that the window opened by focus_issues.feature stays on top (this will be the window showing your root_path with randomly focused input elements).
• Wait until your flickering tests fail. You might need to run tests for a few times until this happens, because there are still external factors involved in the timing.
• Cucumber will seem to hang until focus_issues.feature has finished its duration. You can CTRL+C out of that.

You can now fix your focus-sensitive tests.