js ----反函数劫持 wind.close

  window.close = function () {};
    window.close = "";
    var test = "function () { [native code] }";


    window.QWCy_11 = window.close;
    var bol = QWCy_11.toString() === test ? true : false;
    console.log(bol)
    window.close = function (a = 1) {
        console.log(window.close)
        if (typeof window.QWCy_11 === "function") {
            if (bol) {
                window.QWCy_11();
                return a;
            } else {
                return -1;
            }
        } else {
            return -1;
        }
    };

    if (typeof window.close === "function") {
        console.log("----" + window.close())
        console.log(window.close.length)
        if (window.close() === -1) {
            while (1) {
                alert("函数被重写了");
            }
        }
    }