factory-proxy-example.js

class StreamPot {
    num = 0;
    doIt() {
        this.num += 42;
        return this;
    }
}

const streamPotFactory = () => new Proxy(new StreamPot, {
    get: (target, prop, receiver) => {
        if (typeof target[prop] === 'function') {
            const instance = new StreamPot();
            return (instance)[prop].bind(instance)
        }
    }
});

const ourStreamPotInstance = streamPotFactory()
const a = ourStreamPotInstance.doIt()
const b = ourStreamPotInstance.doIt().doIt()

console.log(a.num)
console.log(b.num)