Test for a specific problem with previousNode that failed in older versions of WebKit. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS walker.firstChild(); walker.currentNode.id is 'A1' PASS walker.nextNode(); walker.currentNode.id is 'B1' PASS walker.nextNode(); walker.currentNode.id is 'C1' PASS walker.nextNode(); walker.currentNode.id is 'B2' PASS walker.previousNode(); walker.currentNode.id is 'C1' PASS successfullyParsed is true TEST COMPLETE