This tests if the parent block has the correct size when the child element has fixed width as zero. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS successfullyParsed is true TEST COMPLETE PASS document.getElementById("p_topRight").getClientRects()[0].width is 50 PASS document.getElementById("p_botRight").getClientRects()[0].width is 50 PASS successfullyParsed is true TEST COMPLETE