JavaScript通过new Error() hack方法从函数体内部获取函数名

'use strict'

function getFuncName (){
    var callerName;
    {
        let reg = /(\w+)@|at ([^(]+) \(/g;
        reg.exec(new Error().stack);  //跑一次exec, 跑到第二个匹配
        let regResult = reg.exec(new Error().stack);
        callerName = regResult[1] || regResult[2];
    }
    console.log(callerName);
};

function funcToKnow (){
   getFuncName();
};

funcToKnow();  //funcToKnow