How to Test Blur - Firefox Selenium driver?

Some elements do not have a suitable discriminator for testing purposes (e.g. an id or another CSS selector that you'd like to be bound to in your tests).

Fortunately, the notion of an activeElement exisits. So, if the element's blur functionality is what you wish to test, a native javascript way (not reliant upon jQuery or similar) to test this is:

driver.ExecuteScript("!!document.activeElement ? document.activeElement.blur() : 0");

The selenium WebDriver does not properly trigger events like blur. You can, however, manually trigger them. Assuming that you're using jquery:

firefoxWebDriver.executeScript("$('#yourID').blur()");

Or without jquery:

firefoxWebDriver.executeScript("document.querySelector('#yourID').blur()");