INNER CODE UNIT · TypeScript

EventEmitter

mongodb-js/mongodb-mcp-server · packages/browser-tests/polyfills/events/index.ts:4

export class EventEmitter {
    private events: Map<string | symbol, Array<(...args: any[]) => void>> = new Map();

    on(event: string | symbol, listener: (...args: any[]) => void): this {
        if (!this.events.has(event)) {
            this.events.set(event, []);
        }
        this.events.get(event)!.push(listener);
        return this;
    }

    once(event: string | symbol, listener: (...args: any[]) => void): this {
        const onceWrapper = (...args: any[]) => {
            this.off(event, onceWrapper);
            listener(...args);
        };
        return this.on(event, onceWrapper);
    }

View source record →