gistfile1.txt

var Button = React.createClass({
    render: function() {
        return this.transferPropsTo(<div style={{ border: "1px solid gray" }} className="button" />);
    }
});

<Button style={{ background-color: "blue" }} className="blue-button" />

->

<div style={{ border; "1px solid gray", background-color: "blue" }} className="button blue-button" />