How can I use proxy with spread operator or object.assign?

Question

I need to have methods and store bound to 'this' in my callback function, but when I use the spread operator it doesn't work. The reason for this as far as I know is that the spread operator returns a copy of the original. Therefore the proxy is never triggered.

What could I do in this case to make the proxy trigger?

const setup = function (options, cb) {
  let store = new Proxy(options.store, {
    set(target, prop, value) {
      console.log(`changed ${prop} from ${target[prop]} to ${value}`);
      target[prop] = value;
      return true;
    },
  });
  cb.bind(store)(); // Works as expected
  // cb.bind({ ...store, ...methods })(); // Doesn't work
};

setup(
  {
    store: {
      n: 123,
    },
  },
  function () {
    this.n = 456;
  }
);

Answer 1

After removing the unbound methods variable, your example works as expected.

You won't see the message being printed. That's to be expected, since the expression {...store} essentially clones the (proxy) object store, with the effect that a new (regular) object is created and passed to bind and modified there.