Three Monkeys, Three Typewriters, Two Days

It's bug 200930 for those that are interested.

Specifically, what type of tests are you looking for? Are you looking for a test case that specifies alternate stylesheets, or one that attempts to set the active stylesheet programatically?

Both. I'm looking for tests that test all aspects of that specification -- the values of the various DOM properties depending on the initial stylesheets sent with the page, the behavior when script toggles the various properties, the interactions between setting the properties and then getting a preferred sheet specified, etc. That is, actual testing of compliance with this spec. I estimate that somewhere around 30 to 100 tests are needed for this.