graphiql koa 0.9.0 Error: Can't set headers after they are sent

[vladshcherbin]

After updating to graphql-server-koa 0.9.0, there is an error when trying to use graphiql. Graphql itself is working. No error in 0.8.5.

Error: Can't set headers after they are sent.

Updated packages:

- graphql-server-core@0.9.0
- graphql-server-koa@0.9.0
- graphql-server-module-graphiql@0.9.0

Env:

• node 8.1.2
• mac os 10.12.5
• koa 2.3.0
• koa-router 7.2.1
• koa-bodyparser 4.2.0

Code:

import { createServer } from 'http'
import Koa from 'koa'
import Router from 'koa-router'
import koaBody from 'koa-bodyparser'
import { graphqlKoa, graphiqlKoa } from 'graphql-server-koa'
import schema from './graphql'

const app = new Koa()
const router = new Router()

router
  .get('/', async (ctx) => {
    ctx.body = 'Main / Home'
  })
  .get('/graphiql', graphiqlKoa({ endpointURL: '/graphql' }))
  .post('/graphql', koaBody(), graphqlKoa({ schema }))

app
  .use(router.routes())
  .use(router.allowedMethods())

const server = createServer(app.callback())

server.listen(3000)

[DxCx]

is that still happens on version 1.0.0?
anyway, this is the diff between the versions:
0d5add0

@NeoPhi can you take a look at that?

[vladshcherbin]

@DxCx yes, this also happens on 1.0.0.

I think, await is missing in graphiql resolution somewhere here.

[vladshcherbin]

This was fixed.

[arvi]

@vladshcherbin hello what was the fix? Can you post the commit id? Thanks a lot. I am having the same issue on a different package graphql/graphql-playground#557

[vladshcherbin]

@arvi this one I guess: c22bb37

[arvi]

@vladshcherbin thanks, reported it to graphcool 😄