query returns null instead of value

[msadovyi]

Describe the bug

Hi! I'm trying to run graphql-mesh with 1 handler that uses graphql-ws as transport. It seems like queries does not works correctly with graphql-ws.

To Reproduce
Clone https://github.com/msadovyi/mesh-graphql-ws-issue

1. Run yarn && yarn start. It runs source API at port 3000 and grapql-mesh at port 4000.
2. Open http://localhost:3000 and make sure query { hello } and subscription subscription { greetings } return values.
3. Open http://localhost:4000 and execute same queries: { hello }, subscription { greetings }.

Expected behavior
Both of queries works correctly and returns values as source API does.

Environment:

• Dependencies:

"@graphql-mesh/cli": "^0.30.2",
"@graphql-mesh/graphql": "^0.17.10",
"apollo-server-express": "^2.25.1",
"express": "^4.17.1",
"graphql": "^15.5.0",
"graphql-ws": "^5.1.2",
 "ws": "^7.4.6"

• NodeJS: v14.16.1

[Davenporten]

Can you give a little more context? When you run the subscription does an error come back? Or is it just hanging?