Support "appearance"?

I see that appearance is not supported equally through different browsers, but maybe at least some

appearance: none
-webkit-appearance: none
-moz-appearance: none

support would be nice?

[ai]

@jasonkuhrt create a PostCSS plugin for this non-standard cases, like @yisibl created CSS Grace for IE hacks.

I want to add this property too. But I can’t do it. Becuase after few years there will be no prefixes. And right now Autoprefixer works in that case, that you will remove it after few years.

If your CSS will contains appearance: none, it will be broken without Authoprefixer.

Of course, we can add warnings and extra options. But right now Autoprefixer is the slowest PostCSS plugin because of many extra non-standard cases. Autoprefixer’s code base is complicated, so only I maintain it. Extra option for this non-standard cases make it more complicated. And we have no really reasons for this victims.

You can really write PostCSS plugin for appearance by few lines of code:

module.exports = function (css) {
    css.eachDecl('appearance', function (decl) {
        if ( decl.value != 'none' ) return;
        decl.cloneBefore({ prop: '-webkit-appearance' });
        decl.cloneBefore({ prop: '-moz-appearance' });
        decl.removeSelf();
    });
};

Thats all! You need only README.md and tests. You can use postcss-size plugin a boilerplate.

[jasonkuhrt]

To be clear, I think if the data is available in Can I Use, we should support it. People _will_ benefit from it, and if the sticking point is “non-standard” then we just need to correctly _frame/_communicate the feature; its an _interface_ issue. Saying “nope, we’re not going to support this” is dumb if the underlaying data is available and _people are already using this anyways_.