如何测试对象是否是代理? [英] How to test if an object is a Proxy?

问题描述

我想测试一个 JavaScript 对象是否是 代理.琐碎的方法

I would like to test if a JavaScript object is a Proxy. The trivial approach

if (obj instanceof Proxy) ...

在这里不起作用，也不会遍历 Proxy.prototype 的原型链，因为所有相关操作都由底层目标有效支持.

doesn't work here, nor does traversing the prototype chain for Proxy.prototype, since all relevant operations are effectively backed by the underlying target.

是否可以测试任意对象是否为代理?

Is it possible to test if an arbitrary object is a Proxy?

推荐答案

在我当前的项目中，我还需要一种方法来定义某物是否已经是代理，主要是因为我不想在代理上启动代理.为此，我只是在我的处理程序中添加了一个 getter，如果请求的变量是__Proxy"，它将返回 true:

In my current project I also needed a way of defining if something was already a Proxy, mainly because I didn't want to start a proxy on a proxy. For this I simply added a getter to my handler, which would return true if the requested variable was "__Proxy":

function _observe(obj) {
  if (obj.__isProxy === undefined) {
    var ret = new Proxy(obj || {}, {
      set: (target, key, value) => {
        /// act on the change
        return true;
      },
      get: (target, key) => {
        if (key !== "__isProxy") {
          return target[key];
        }

        return true;
      }
    });
    return ret;
  }

  return obj;
}

可能不是最好的解决方案，但我认为这是一个优雅的解决方案，在序列化时也不会弹出.

Might not be the best solution, but I think it's an elegant solution, which also doesn't pop up when serializing.

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