sergey-telpuk / nestjs-transport-eventbus

import { Injectable, Type } from '@nestjs/common';

import { ModuleRef } from '@nestjs/core';

import { Transport } from '@nestjs/microservices';

import { EVENT_NAME, EXCLUDE_DEF, TRANSPORT, TRANSPORTS } from './constants/transport.event-bus.constants';

@Injectable()

export class TransportEventBusService implements IEventBus {

    constructor(

        readonly publishers: any[],

        readonly eventBus: EventBus,

        private readonly moduleRef: ModuleRef

    ) {

    }

    get publisher(): IEventPublisher {

        return this.eventBus.publisher;

    }

    onModuleDestroy(): void {

        this.eventBus.onModuleDestroy();

    }

    bind(handler: IEventHandler<IEvent>, name: string): void {

        this.eventBus.bind(handler, name);

    }

    registerSagas(types?: Array<Type<any>>): void {

        this.eventBus.registerSagas(types);

    }

    register(handlers?: EventHandlerType[]): void {

        this.eventBus.register(handlers);

    }

    publishAll<T extends IEvent>(events: T[]): void {

        events.forEach((event: T) => {

            this.publishViaPublisher(event);

        });

    }

    private publishViaPublisher<T extends IEvent>(event: T): void {

        const transports: Transport[] = event[TRANSPORTS] ? event[TRANSPORTS] : [];// tslint:disable-line

        const isExcludedDef: boolean = !!event[EXCLUDE_DEF] || false;// tslint:disable-line

        delete event[TRANSPORTS];// tslint:disable-line

        delete event[EXCLUDE_DEF];// tslint:disable-line

        for (const publisher of this.publishers) {

            const pub = this.moduleRef.get<IEventPublisher>(publisher);

            if (transports.includes(pub[TRANSPORT])) {// tslint:disable-line

                pub.publish(event);

            }

        }

        if (!isExcludedDef) {

            delete event[EVENT_NAME];// tslint:disable-line

            this.eventBus.publish(event);

        }

    }

}