Safari Selenium driver wrapped ready to use with ddry.
For macOS only. In other environments fallbacks to geckodriver.
Don't forget to enable Develop > Allow Remote Automation in your Safari before use or you'll be notified about that on the first test attempt.
Safari is extremely tender and vulnerable in parallel running matters. To handle this precious load balancing ddry has modular/Makefile workaround.
Please take a look at main.coffee file containing core spec config and the rest spec files simply applying specific constraints to it.
Then Makefile explains quite comfortable way to feed partial tasks to Mocha.
Adjust partial tasks and sleep times to achieve the full stability of testing in your environment.