简单的while循环set Object 属性 （有则合并，无则

function setDescendantProp(obj, desc, fun) {
    const arr = desc.split('.');
    let prop = arr.shift();

    // 循环路径赋值
    while (arr.length){
        if(!obj[prop]){
            obj[prop] = {};
        }
        // eslint-disable-next-line no-param-reassign
        obj = obj[prop]
        prop = arr.shift();
    }

    obj[prop] = fun;
}


path：目标位置
value：目标值
obj：目标
function editFn(path, value, obj) {
    const arr = path.split('.')
    const len = arr.length - 1
    arr.reduce((cur, key, index) => {
        if (!(cur[key]))
            throw `${key} 不存在!`
        if (index === len) {
            cur[key] = value
        }
        return cur[key]
    }, obj)
}