CSS vs. XPath, Under a Microscope

NOTE: This is part 2 of 3. For the first installment, go here. For the last installment, go here.

Intro

In a previous tip we reviewed the performance of CSS vs. XPath against Sauce Labs. While it demonstrated that each locator strategy is reasonably equivalent across browsers, it didn't adequately paint the whole picture for us.

Given that it was an end-to-end test there were a lot of variables at play -- Sauce startup, browser start up, and latency to and from the application under test. The unfortunate takeaway from that experiment could be that one driver may be faster than the other (e.g. IE vs Firefox), when in fact, that's not the case at all.

A Solution

To get a real taste of what the performance difference is between CSS and XPath, we will need to dig deeper. We'll do that by running everything from a local machine while using a performance benchmarking utility. We'll also want to focus on a specific Selenium action rather than the entire test run, and run things numerous times.