Poor man pubsub firebase function emulator

pubsub_emulator.ts

import { PubSub } from '@google-cloud/pubsub'
import * as a from './index'
import { CloudFunction } from 'firebase-functions'
import { Message } from '@google-cloud/pubsub'
import * as dotenv from 'dotenv'
dotenv.config()

const pubsub = new PubSub({
  projectId: process.env.GCLOUD_PROJECT
})

console.info(`[pubsub] Starting pubsub server for receiving messages`)
const run = async () => {
  for (let key in a) {
    let value = a[key]
    if (
      value.__trigger.eventTrigger &&
      value.__trigger.eventTrigger.eventType &&
      'google.pubsub.topic.publish' === value.__trigger.eventTrigger.eventType
    ) {
      const topicName = value.__trigger.eventTrigger.resource.split('/')[3]
      if (!topicName) {
        continue
      }
      const topic = pubsub.topic(topicName)
      const topicInst = await topic
        .get()
        .then(t => Promise.resolve(t[0]))
        .catch(e => topic.create().then(t => t[0]))

      const subscription = await topicInst
        .createSubscription(`${key}-${topicName}`)
        .then(t => Promise.resolve(t[0]))
        .catch(e => pubsub.subscription(`${key}-${topicName}`))

      const runFunction = key => (f: CloudFunction<Message>) => async (
        msg: Message
      ) => {
        console.info(`i  functions: Beginning execution of ${key}`)
        try {
          await f.run(msg, { eventId: 'eid' })
          msg.ack()
          console.info(`i  functions: Finished execution of ${key}`)
        } catch (err) {
          console.error(`e  functions: Errors in execution of ${key}: ${err}`)
        }
      }
      console.info(`✔  functions Registering ${key} with ${subscription.name}`)
      subscription.on(`message`, runFunction(key)(value))
    }
  }
}

run()
  .then(() => console.info(`✔  pubsub server running and awaiting message`))
  .catch(console.error)

start the emulator first gcloud beta emulators pubsub --verbosity=none --quiet start

.env file

FIREBASE_CONFIG = 
GCLOUD_PROJECT = 
GOOGLE_APPLICATION_CREDENTIALS=
FIRESTORE_EMULATOR_HOST = 
GOOGLE_CLOUD_PROJECT= ```