HTMLTableElement's rows order is not tested in wpt

[domenic]

Porting from https://www.w3.org/Bugs/Public/show_bug.cgi?id=29018.

The order of rows in that collection is apparently not interoperable between browsers. There are competing proposals, with @foolip and @zcorpan proposing (in https://www.w3.org/Bugs/Public/show_bug.cgi?id=29018#c7):

something that matches the prose for table-header-group and table-footer-group in http://www.w3.org/TR/CSS2/tables.html#table-display

and @annevk proposing (https://www.w3.org/Bugs/Public/show_bug.cgi?id=29018#c16):

FWIW, I think what the standard says today here makes the most sense. We should simply change Firefox and Edge.

For the record, as of today the standard says

The elements in the collection must be ordered such that those elements whose parent is a thead are included first, in tree order, followed by those elements whose parent is either a table or tbody element, again in tree order, followed finally by those elements whose parent is a tfoot element, still in tree order.

I tend to agree the standard sounds pretty nice and simple, and we should consider just writing tests and filing a Firefox bug, with no spec changes.

[zcorpan]

I believe @annevk opinion was based on misunderstanding my and @foolip's proposal (that it would be based on the rendering).

The proposal is:

• Move the first thead so that its rows are first in the list.
• Move the first tfoot so that its rows are last in the list.
• Don't move any other rows.

This matches default rendering, and is strictly less moving of rows than what the spec does today.

[domenic]

And I guess Blink and WebKit match the current spec, whereas Gecko matches your proposal? But, we want to write web platform tests to confirm?

[zcorpan]

Looking at http://software.hixie.ch/utilities/js/live-dom-viewer/?saved=3778 in Firefox Nightly it seems it matches the current spec now also.

[muodov]

I'd like to work on this. If I understand correctly, there is no compatibility problems between the major browsers and the spec, and we just need the tests?
Should I create a corresponding issue in the web-platform-tests repo, or just file a PR right away?

[annevk]

That's great! And yeah, I think that's correct. web-platform-tests uses issues for coordination or backlog. If you can address something immediately (i.e., via a PR) there's no need for an issue.

[muodov]

Hm, it seems like there is already a test for this. The "complicated case" test case asserts the results of the following HTML, which seems to cover the cases discussed here. E.g. it is asserted that all tfoot rows, including the first one, are returned after all the thead and tbody rows, just like the spec says.

Asserted HTML

<table>
    <tr id="orphan1"></tr>
    <tfoot>
        <tr id="foot1row1"></tr>
        <tr id="foot1row2"></tr>
        <div>
            <tr></tr>
        </div>
        <tr></tr>
    </tfoot>
    <tr id="orphan2"></tr>
    <tfoot>
        <tr id="foot2row1"></tr>
        <tr id="foot2row2"></tr>
    </tfoot>
    <tr id="orphan3"></tr>
    <tbody>
        <tr id="body1row1"></tr>
        <tr id="body1row2"></tr>
        <div>
            <tr></tr>
        </div>
        <tr></tr>
    </tbody>
    <tr id="orphan4"></tr>
    <tbody>
        <tr id="body2row1"></tr>
        <tr id="body2row2"></tr>
    </tbody>
    <tr id="orphan5"></tr>
    <thead>
        <tr id="head1row1"></tr>
        <tr id="head1row2"></tr>
        <div>
            <tr></tr>
        </div>
        <tr></tr>
    </thead>
    <tr id="orphan6"></tr>
    <thead>
        <tr id="head2row1"></tr>
        <tr id="head2row2"></tr>
    </thead>
    <tr id="orphan7"></tr>
    <div>
        <tr></tr>
    </div>
    <tr></tr>
</table>

This test is passing in all browsers monitored by wpt.fyi. Shall we just close this ticket? :)

[annevk]

Thanks, it seems that test was made as part of fixing the bug in Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1264947. So yeah, everything is in order!

[domenic]

Thank you @muodov for your willingness to dive in and help us close this out!