How to check if graphql yoga server is running locally?

I have a pubsub service running with Redis and I need to check if GraphQL Yoga server is up and running locally before I start it.

What's the best way to do it in Node.js with TypeScript?

healthCheckEndpoint is set to 'live', port 4000

In order to ensure Redis doesn't connect until GraphQL is running, you can import the redis library asynchronously inside the server's success callback.

index.js

import { createServer } from "node:http";
import { createYoga } from "graphql-yoga";
import { schema } from "./schema.js";
import redis from "./redis.js";

// Create a Yoga instance with a GraphQL schema.
const yoga = createYoga({ schema });

// Pass it into a server to hook into request handlers.
const server = createServer(yoga);

// Start the server and you're done!
server.listen(4000, async () => {
  console.info("GraphQL server is running on http://localhost:4000/graphql");

  await redis();

  return Promise.resolve();
});

redis.js

import Redis from "ioredis";

export default async () => {
  const redis = new Redis();
  return redis.set("mykey", "value");
};