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Re: UAs passing tests if they don't implement a feature

From: Aryeh Gregor <ayg@aryeh.name>
Date: Wed, 20 Jun 2012 10:33:51 +0300
Message-ID: <CAKA+AxnQpwpA1n7YC=tmgkuVY9RnsZBEk6NiFDMV7aCnnebJxA@mail.gmail.com>
To: "Linss, Peter" <peter.linss@hp.com>
Cc: CSS-testsuite <public-css-testsuite@w3.org>
On Tue, Jun 19, 2012 at 11:51 PM, Linss, Peter <peter.linss@hp.com> wrote:
> The answer to this lies in the question, what are you testing for? If you're testing for _not_ implementing a feature, i.e. rotate with a percentage value, then an implementation that doesn't support transform should pass. If you're testing for rejecting percentages in an implementation of rotate, then a non-supporting implementation should not pass…

I'm not sure what this means.

> In this particular case, I second Simon's recommendation of a != ref to force a fail in UAs that don't implement transform at all. I'd think the != ref should be the rotated version (which should not be rendered via a rotate…). The two ways I can think to do that are: 1) render the rotated version in SVG using pre-computed coordinates, or 2) change your rotation to something that would be 90deg (25%?) and use a rectangular object as your rotation target.

I don't understand.  What would the purpose be of a != ref that tests
that the object isn't rotated by 10% (whatever that means)?  In this
hypothetical case, there's already an == ref of the object unrotated.
Any UA that passes that will obviously pass the != ref, so what does
it add?

Or take a real example:
http://test.csswg.org/shepherd/testcase/transform-background-006  That
tests that if you transform the body and specify a background on the
body, with no background on the root element, the background is not
transformed (because the background is really rendered on the root
element, which isn't transformed).  The reference is basically just
the same file but without the transform.

What change would you suggest I make there?  Adding a != ref that has
the background rotated wouldn't add anything, because anything that
passed the == ref would pass the != ref too.  I could add some text or
something and verify that that's rotated to fail UAs that don't
support transforms at all, but that would add material to the test
that's not related to what it's testing.

What's wrong with a UA that doesn't support transforms at all passing
this particular test-case?
Received on Wednesday, 20 June 2012 07:34:45 GMT

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