This test checks if checkValidity() returns correctly a true (meaning no error) result. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". lorem ipsum PASS document.getElementsByTagName("fieldset")[0].checkValidity() is true PASS document.getElementsByTagName("input")[0].checkValidity() is true PASS document.getElementsByTagName("button")[0].checkValidity() is true PASS document.getElementsByTagName("select")[0].checkValidity() is true PASS document.getElementsByTagName("textarea")[0].checkValidity() is true PASS document.getElementsByTagName("output")[0].checkValidity() is true PASS document.getElementsByTagName("object")[0].checkValidity() is true PASS document.getElementsByTagName("keygen")[0].checkValidity() threw exception TypeError: document.getElementsByTagName("keygen")[0].checkValidity is not a function. (In 'document.getElementsByTagName("keygen")[0].checkValidity()', 'document.getElementsByTagName("keygen")[0].checkValidity' is undefined). PASS successfullyParsed is true TEST COMPLETE