Default value of tabIndex IDL attribute On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS anchor.tabIndex is 0 PASS iframe.tabIndex is 0 PASS frame.tabIndex is 0 PASS object.tabIndex is 0 PASS button.tabIndex is 0 PASS input.tabIndex is 0 PASS select.tabIndex is 0 PASS textarea.tabIndex is 0 PASS keygen.tabIndex is 0 PASS activeSummary.tabIndex is 0 PASS editableDiv.tabIndex is -1 PASS normalDiv.tabIndex is -1 PASS output.tabIndex is -1 PASS fieldset.tabIndex is -1 PASS video.tabIndex is -1 PASS videoWithControls.tabIndex is -1 PASS summary.tabIndex is -1 PASS bodyInDesignMode.tabIndex is -1 PASS g.tabIndex is -1 PASS mrow.tabIndex is -1 PASS anchor.setAttribute("tabindex", "invalid"); anchor.tabIndex is 0 PASS iframe.setAttribute("tabindex", "invalid"); iframe.tabIndex is 0 PASS frame.setAttribute("tabindex", "invalid"); frame.tabIndex is 0 PASS object.setAttribute("tabindex", "invalid"); object.tabIndex is 0 PASS button.setAttribute("tabindex", "invalid"); button.tabIndex is 0 PASS input.setAttribute("tabindex", "invalid"); input.tabIndex is 0 PASS select.setAttribute("tabindex", "invalid"); select.tabIndex is 0 PASS textarea.setAttribute("tabindex", "invalid"); textarea.tabIndex is 0 PASS keygen.setAttribute("tabindex", "invalid"); keygen.tabIndex is 0 PASS activeSummary.setAttribute("tabindex", "invalid"); activeSummary.tabIndex is 0 PASS editableDiv.setAttribute("tabindex", "invalid"); editableDiv.tabIndex is -1 PASS normalDiv.setAttribute("tabindex", "invalid"); normalDiv.tabIndex is -1 PASS output.setAttribute("tabindex", "invalid"); output.tabIndex is -1 PASS fieldset.setAttribute("tabindex", "invalid"); fieldset.tabIndex is -1 PASS video.setAttribute("tabindex", "invalid"); video.tabIndex is -1 PASS videoWithControls.setAttribute("tabindex", "invalid"); videoWithControls.tabIndex is -1 PASS summary.setAttribute("tabindex", "invalid"); summary.tabIndex is -1 PASS bodyInDesignMode.setAttribute("tabindex", "invalid"); bodyInDesignMode.tabIndex is -1 PASS g.setAttribute("tabindex", "invalid"); g.tabIndex is -1 PASS mrow.setAttribute("tabindex", "invalid"); mrow.tabIndex is -1 PASS anchor.setAttribute("tabindex", "9999999999"); anchor.tabIndex is 0 PASS iframe.setAttribute("tabindex", "9999999999"); iframe.tabIndex is 0 PASS frame.setAttribute("tabindex", "9999999999"); frame.tabIndex is 0 PASS object.setAttribute("tabindex", "invalid"); object.tabIndex is 0 PASS button.setAttribute("tabindex", "9999999999"); button.tabIndex is 0 PASS input.setAttribute("tabindex", "9999999999"); input.tabIndex is 0 PASS select.setAttribute("tabindex", "9999999999"); select.tabIndex is 0 PASS textarea.setAttribute("tabindex", "9999999999"); textarea.tabIndex is 0 PASS keygen.setAttribute("tabindex", "9999999999"); keygen.tabIndex is 0 PASS activeSummary.setAttribute("tabindex", "9999999999"); activeSummary.tabIndex is 0 PASS editableDiv.setAttribute("tabindex", "9999999999"); editableDiv.tabIndex is -1 PASS normalDiv.setAttribute("tabindex", "9999999999"); normalDiv.tabIndex is -1 PASS output.setAttribute("tabindex", "9999999999"); output.tabIndex is -1 PASS fieldset.setAttribute("tabindex", "9999999999"); fieldset.tabIndex is -1 PASS video.setAttribute("tabindex", "9999999999"); video.tabIndex is -1 PASS videoWithControls.setAttribute("tabindex", "9999999999"); videoWithControls.tabIndex is -1 PASS summary.setAttribute("tabindex", "9999999999"); summary.tabIndex is -1 PASS bodyInDesignMode.setAttribute("tabindex", "9999999999"); bodyInDesignMode.tabIndex is -1 PASS g.setAttribute("tabindex", "9999999999"); g.tabIndex is -1 PASS mrow.setAttribute("tabindex", "9999999999"); mrow.tabIndex is -1 PASS successfullyParsed is true TEST COMPLETE