graphql yoga in Hono server

aaa.ts

import {Env, Hono, HonoRequest} from "hono";
import {createSchema, createYoga} from "graphql-yoga";

const schema = createSchema({
    typeDefs: `...graphql schema...`,
    resolvers: {
        Query: {
            hello: () => 'Hello wolrd :)',
        },
        Subscription: {
            countdown: {
                subscribe: async function* (_, {from}) {
                    for (let i = from; i >= 0; i--) {
                        await new Promise((resolve) => setTimeout(resolve, 1000))
                        yield {countdown: i}
                    }
                }
            }
        }
    }
})

const yoga = createYoga({
    schema,
    graphqlEndpoint: '/api/graphql',
});

// adapted from https://github.com/hagishi/hono-graphql-yoga that was not updated
app.use('/api/graphql', async (c) => {
    const ctx = Object.prototype.hasOwnProperty.call(c, 'executionCtx') ? c.executionCtx : {}
    return yoga.handleRequest(c.req, {
        env: c.env,
        ctx,
    })
})

This should work if you're deploying to Cloudflare Workers:

import { Hono } from 'hono'
import { createSchema, createYoga } from 'graphql-yoga'

const schema = createSchema({
  typeDefs: () => /* graphql */`
    type Query {
      health: String
    }
  `,
  resolvers: {
    Query: {
      health: () => `OK`
    },
  }
})

const yoga = createYoga({
  schema,
  graphqlEndpoint: '/graphql'
})

const app = new Hono()

export default {
  app,
  fetch: yoga.fetch
}