PubSub with Deno

pubsub.ts

import { Hono } from "jsr:@hono/hono@^4.4.0"
import { PubSub } from "npm:@google-cloud/pubsub"
import { Buffer } from "node:buffer"
import * as queryString from "npm:[email protected]"

const pubSub = new PubSub({
  projectId: Deno.env.get("PROJECT_ID"),
  keyFilename: Deno.env.get("GOOGLE_APPLICATION_CREDENTIALS"),
})

const app = new Hono()

async function publishMessage(topicName, message) {
  try {
    const [topic] = await pubSub.topic(topicName).get({ autoCreate: true })
    const messageId = await topic.publish(message.data, message.attributes)
    console.log(`Message ${messageId} published.`)
    return messageId
  } catch (error) {
    console.error("Error publishing message:", error)
  }
}

app.post("/:topic/:itemId?", async (c) => {
  const { req: request } = c
  const topicName = request.param("topic")
  const itemId = request.param("itemId")

  const contentType = request.header("Content-Type")
  let notificationPayload

  if (contentType === "application/json") {
    notificationPayload = JSON.stringify(await request.json())
  } else if (contentType === "text/plain") {
    notificationPayload = await request.text()
  } else if (contentType === "application/x-www-form-urlencoded") {
    notificationPayload = JSON.stringify(await request.parseBody())
  } else {
    return new Response("Unsupported content type", { status: 415 })
  }

  const { url, headers } = request.raw
  const queryParams = queryString.parse(new URL(url).searchParams.toString())
  console.log(headers)
  const message = {
    data: Buffer.from(notificationPayload),
    attributes: {
      itemId: itemId || "",
      queryParams: JSON.stringify(queryParams),
      headers: JSON.stringify(headers),
    },
  }
  const messageId = await publishMessage(topicName, message)

  return c.json({
    messageId,
    topicName,
    itemId,
  })
})

Deno.serve(app.fetch)

// xh post 'localhost:8000/test-topic/123123123123?tags=a&tags=1&a=2&b=456' hello=world
// xh post 'localhost:8000/test-topic?tags=a&tags=1&a=2&b=456' hello=world