Run results for: Custom Event vs PubSub

Run details:

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Mobile Safari/537.36

Browser: Chrome Mobile 120

Operating system: Android

Device Platform: Mobile

Date tested: 10 months ago

Test name	Executions per second
Custom Event	817.3 Ops/sec
PubSub	32573.4 Ops/sec

Script Preparation code:

class PubSub {
    constructor() {
        this.events = {};
    }


    subscribe(event, callback) {
        if (!this.events.hasOwnProperty(event)) {
            this.events[event] = [];
        }

        return this.events[event].push(callback);
    }

    publish(event, data = {}) {
        if (!this.events.hasOwnProperty(event)) {
            return [];
        }

        return this.events[event].map((callback) => callback(data));
    }
}

Tests:

Custom Event
let i = 1001; const results = []; while (--i) { window.dispatchEvent(new CustomEvent('custom:test')); }
PubSub
class PubSub { constructor() { this.events = {}; } subscribe(event, callback) { if (!this.events.hasOwnProperty(event)) { this.events[event] = []; } return this.events[event].push(callback); } publish(event, data = {}) { if (!this.events.hasOwnProperty(event)) { return []; } return this.events[event].map((callback) => callback(data)); } } const pubSub = new PubSub(); let i = 1001; const results = []; while (--i) { pubSub.publish('custom', 'test') }