Major use cases for ES6 proxies

Question

I recently got to know about ES6 proxies but I don\'t see a good reason to use it. I mean, everything that one could do with Proxy can be done without it, except if I\'m mis

Answer 1

I mean, every thing that one could do with Proxy can be done without it...

That isn't remotely true.

Consider the common need to catch access to properties that don't exist:

const o = {foo: "bar"};
console.log(o.blarg);

It's common to want to handle that in a way other than the default, which is to log undefined. Proxy lets us do that, via the get trap. Example:

const o = {foo: "bar"};
const p = new Proxy(o, {
  get(target, prop, receiver) {
    return prop in target ? target[prop] : "nifty!";
  }
});
console.log(p.foo);
console.log(p.blarg);

Another example is the ability to hook into the various operations that get the list of properties on an object. There is no way to hook into that without Proxy. With Proxy, it's easy: You use the has trap or the ownKeys trap depending on what you want to hook into.

In terms of other use cases: Proxy is the ultimate tool for implementing the Facade pattern. Look for the use cases of Facade, and you'll find use cases for Proxy.