Rocket.Chat/apps/meteor/client/lib/toast.ts

import { Emitter } from '@rocket.chat/emitter';
import type { ReactNode } from 'react';

type ToastMessagePayload =
	| {
			type: 'success' | 'info' | 'warning';
			message: ReactNode | string;
			title?: string;
			options?: object;
	  }
	| {
			type: 'error';
			message: unknown;
			title?: string;
			options?: object;
	  };

const emitter = new Emitter<{
	notify: ToastMessagePayload;
}>();

export const dispatchToastMessage = (payload: ToastMessagePayload): void => {
	// TODO: buffer it if there is no subscriber
	emitter.emit('notify', payload);
};

export const subscribeToToastMessages = (callback: (payload: ToastMessagePayload) => void): (() => void) => emitter.on('notify', callback);