Bug: Cannot set headers after they are sent to the client

[cschroeter]

I'm submitting a...

[ ] Regression 
[x] Bug report
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead post your question on Stack Overflow.

Current behavior

import graphqlPlayground from 'graphql-playground-middleware-express';

// ...
 consumer
      .apply(
        // Here the error happens
        graphqlPlayground({
          endpoint: '/graphql',
          subscriptionsEndpoint: `ws://localhost:5001/subscriptions`
        })
      )
      .forRoutes('/graphiql')
      .apply(
        graphqlExpress(async req => ({
          schema,
          rootValue: req,
          context: req,
          formatError: (error: GraphQLError) => {
            return error.originalError instanceof BaseException ? error.originalError.serialize() : error;
          }
        }))
      )
      .forRoutes('/graphql');

(node:10937) UnhandledPromiseRejectionWarning: Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
    at ServerResponse.setHeader (_http_outgoing.js:471:11)
    at ServerResponse.header (/Users/cschroeter/Workspace/Playground/graphql-yoga/nest-yoga/node_modules/express/lib/response.js:767:10)
    at ServerResponse.send (/Users/cschroeter/Workspace/Playground/graphql-yoga/nest-yoga/node_modules/express/lib/response.js:170:12)
    at ServerResponse.json (/Users/cschroeter/Workspace/Playground/graphql-yoga/nest-yoga/node_modules/express/lib/response.js:267:15)
    at ExpressAdapter.reply (/Users/cschroeter/Workspace/Playground/graphql-yoga/nest-yoga/node_modules/@nestjs/core/adapters/express-adapter.js:41:52)
    at ExceptionsHandler.next (/Users/cschroeter/Workspace/Playground/graphql-yoga/nest-yoga/node_modules/@nestjs/core/exceptions/exceptions-handler.js:33:29)
    at /Users/cschroeter/Workspace/Playground/graphql-yoga/nest-yoga/node_modules/@nestjs/core/router/router-proxy.js:12:35
    at Layer.handle [as handle_request] (/Users/cschroeter/Workspace/Playground/graphql-yoga/nest-yoga/node_modules/express/lib/router/layer.js:95:5)
    at trim_prefix (/Users/cschroeter/Workspace/Playground/graphql-yoga/nest-yoga/node_modules/express/lib/router/index.js:317:13)
    at /Users/cschroeter/Workspace/Playground/graphql-yoga/nest-yoga/node_modules/express/lib/router/index.js:284:7

Expected behavior

Instead of the classic GraphiQL UI, I would like to use the superior graphql-playground-middleware-express

Environment

"@nestjs/common": "5.0.1",
"@nestjs/core": "5.0.1",
"@nestjs/graphql": "3.0.0",
"@nestjs/mongoose": "5.0.0",
"@nestjs/passport": "1.0.10",
"@nestjs/testing": "5.0.1"

 
For Tooling issues:
- Node version: 10.2.1
- Platform:  Mac OS

[kamilmysliwiec]

Hey @cschroeter,
This issue comes from the playground library: graphql/graphql-playground#557

Temporary workaround:

consumer
      .apply(
        graphqlPlayground({
          endpoint: '/graphql',
        }),
        () => {},
      )
      .forRoutes('/graphiql');

[esingletary]

If anyone gets an error of Expected 1 arguments but got 2, casting it to any does the trick until the bug is fixed.

    (consumer
      .apply as any)(
        graphqlPlayground({
          endpoint: '/graphql',
        }),
        () => { },
    )
      .forRoutes('/graphiql');

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.