graphql-server.ts

import { GraphQLSchema } from 'graphql'
import polka from 'polka'
import { json } from 'body-parser'
import send from '@polka/send-type'
import { renderPlaygroundPage } from 'graphql-playground-html'
import { graphql } from 'graphql'
import { Server } from 'http'

export function serveGraphql(schema: GraphQLSchema): Server {
  const { PORT = 4000 } = process.env

  const app = polka()
    .use(json())
    .get('/', (req, res) => {
      res.writeHead(200, { 'Content-Type': 'text/html; charset=utf-8' })
      res.end(
        renderPlaygroundPage({
          version: '1.7.20',
        }),
      )
    })
    .post('/', async (req, res) => {
      const { variables, query } = req.body
      const data = await graphql({
        schema,
        source: query,
        variableValues: variables,
      })
      send(res, 200, data)
    })
    .listen(PORT, err => {
      if (err) throw err
      console.log(`> Ready on http://localhost:${PORT}/`)
    })

  return app.server
}