declare module "events" {
    class internal extends NodeJS.EventEmitter { }

    interface NodeEventTarget {
        once(event: string | symbol, listener: (...args: any[]) => void): this;
    }

    interface DOMEventTarget {
        addEventListener(event: string, listener: (...args: any[]) => void, opts?: { once: boolean }): any;
    }

    namespace internal {
        function once(emitter: NodeEventTarget, event: string | symbol): Promise<any[]>;
        function once(emitter: DOMEventTarget, event: string): Promise<any[]>;

        /**
         * This symbol shall be used to install a listener for only monitoring `'error'`
         * events. Listeners installed using this symbol are called before the regular
         * `'error'` listeners are called.
         *
         * Installing a listener using this symbol does not change the behavior once an
         * `'error'` event is emitted, therefore the process will still crash if no
         * regular `'error'` listener is installed.
         */
        const errorMonitor: unique symbol;

        class EventEmitter extends internal {
            /** @deprecated since v4.0.0 */
            static listenerCount(emitter: EventEmitter, event: string | symbol): number;
            static defaultMaxListeners: number;

            addListener(event: string | symbol, listener: (...args: any[]) => void): this;
            on(event: string | symbol, listener: (...args: any[]) => void): this;
            once(event: string | symbol, listener: (...args: any[]) => void): this;
            prependListener(event: string | symbol, listener: (...args: any[]) => void): this;
            prependOnceListener(event: string | symbol, listener: (...args: any[]) => void): this;
            removeListener(event: string | symbol, listener: (...args: any[]) => void): this;
            off(event: string | symbol, listener: (...args: any[]) => void): this;
            removeAllListeners(event?: string | symbol): this;
            setMaxListeners(n: number): this;
            getMaxListeners(): number;
            listeners(event: string | symbol): Function[];
            rawListeners(event: string | symbol): Function[];
            emit(event: string | symbol, ...args: any[]): boolean;
            eventNames(): Array<string | symbol>;
            listenerCount(type: string | symbol): number;
        }
    }

    export = internal;
}
