@metamask/swappable-obj-proxy

createSwappableProxy

Creates a Proxy around any object. Retarget the proxy with setTarget.

Installation

yarn add @metamask/swappable-obj-proxy

or

npm install @metamask/swappable-obj-proxy

Usage

createSwappableProxy

const { createSwappableProxy } = require('@metamask/swappable-obj-proxy');

const original = { sayHello: () => 'hi' };
const next = { sayHello: () => 'haay' };
const proxy = createEventEmitterProxy(original);

proxy.sayHello(); //=> "hi"
proxy.setTarget(next);
proxy.sayHello(); //=> "haay"

createEventEmitterProxy

Creates a Proxy around an EventEmitter. If the proxy has setTarget called with a different EventEmitter, all events will be removed from the old target and transferred to the new EventEmitter.

const { createEventEmitterProxy } = require('@metamask/swappable-obj-proxy');

const original = new EventEmitter();
const next = new EventEmitter();
const proxy = createEventEmitterProxy(original);

proxy.on('event', () => console.log('saw event!'));

// triggers the event handler
original.emit('event');

// moves listeners over to next
proxy.setTarget(next);

// does NOT trigger the event handler
original.emit('event');
// DOES trigger the event handler
next.emit('event');