// use-event-bus.ts
import { provide, inject } from '@vue/composition-api';
import EventEmitter from 'eventemitter3';

const EventBusDefaultSymbol = Symbol('Default event bus symbol');

export function provideEventBus(eventBus: EventEmitter, eventBusSymbol = EventBusDefaultSymbol) {
  provide(eventBusSymbol, eventBus);
  return () => provide(eventBusSymbol, undefined);
}

export function useEventBus(eventBusSymbol = EventBusDefaultSymbol) {
  const eventBus = inject(eventBusSymbol);
  if (!eventBus) {
    throw new Error('Event bus not found');
  }
  return eventBus;
}


// parent.vue
import { provideEventBus } from '../../composition/use-event-bus';
...
setup(props, context) {
    const eventBus = new EventEmitter();
    const eventBusSymbol = Symbol('rsm network event bus symbol');

    provideEventBus(eventBus, eventBusSymbol);
    return {
        eventBus,
        eventBusSymbol,
    };
},


// child.vue
import { useEventBus } from '../../composition/use-event-bus';
...
setup(props, context) {
    const eventBusSymbol = props.eventBusSymbol as symbol;
    const eventBus = eventBusSymbol ? useEventBus(eventBusSymbol) : null;

    return {
        eventBus,
    };
},