ty('<custom-ident>'), null, CSSKeywordValue);
    verify_computed_type(generate_property('<custom-ident> | <length>'), 'none', CSSKeywordValue);
}, 'Computed <custom-ident> is reified as CSSKeywordValue');

test(function(){
    verify_computed_type(generate_property('<image>'), null, CSSImageValue);
    verify_computed_type(generate_property('fail | <image> '), 'url(thing.png)', CSSImageValue);
}, 'Computed <image> [url] is reified as CSSImageValue');

test(function(){
    verify_computed_type(generate_prop