This test passes if the nth-of-type(3n + 1) is parsed correctly, regardless of the whitespaces. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS document.defaultView.getComputedStyle(el, null).getPropertyValue('background-color') is 'rgb(0, 128, 0)' PASS document.defaultView.getComputedStyle(el, null).getPropertyValue('background-color') is 'rgb(255, 0, 0)' PASS document.defaultView.getComputedStyle(el, null).getPropertyValue('background-color') is 'rgb(255, 0, 0)' PASS document.defaultView.getComputedStyle(el, null).getPropertyValue('background-color') is 'rgb(0, 128, 0)' PASS successfullyParsed is true TEST COMPLETE