Mix class with function.

mixWithFunc.ts

/**
 * Returns a function mixed with an object.
 * @param obj - Object to mix.
 * @param func - Target function.
 */
function mixWithFunc<T extends Function>(obj: { __proto__?}, func: T) {
    var objProto = <{ constructor }>obj.__proto__;
    var objClass = <{ __mixedProto__ }>objProto.constructor;
    var proto = <typeof obj>objClass.__mixedProto__;
    if (!proto) {
        proto = {};
        proto.__proto__ = objProto;
        ['call', 'apply', 'bind'].forEach(p => proto[p] = Function.prototype[p]);
        objClass.__mixedProto__ = proto;
    }
    (<typeof obj>func).__proto__ = proto;
    Object.getOwnPropertyNames(obj).forEach(p => func[p] = obj[p]);
    return func;
}