[webkit-dev] sharing more test references

[Dirk Pranke]

Hi all,

Currently, we have ~8000 pixel tests in the tree, and ~800 reference
tests. I would like to make that first number a lot smaller.

It turns out that we have a reasonably large number of tests that
produce the exact same pixel results. On chromium-mac on 10.8, for
example, there are 2048 tests that share a result with some other
test. 50 of them, for example, draw a green square in the upper left
corner of the page (e.g., for svg/custom/root-element.html).

The way ref tests are currently implemented, there is no direct way to
say "use test X as a reference for test Y" (although this is in the
W3C specs for ref tests, which suggests using <link> tags in the test
html). Previous conversations on this topic have concluded with us
thinking that we don't want to give up the convention of having an
"-expected" file next to each test, and I still think this is a good
idea.

However, we can probably have our cake and eat it too in many cases by
simply doing something like creating an -expected.html file that
contains solely "<iframe src=path-to-X>".

So, I would like to :

1) document that as an accepted pattern somewhere
2) start building up a directory of shared references, e.g.,
"LayoutTests/references/green-square.html"
3) start converting existing pixel tests to use these.

Anyone think this won't, work, otherwise object, or have better ideas?

-- Dirk