Undefined error if Subscription starts with capital letter in roots

Screenshot

Expected Behaviour

There should not be an error if Subscription is used in roots.

Actual Behaviour

There is an undefined error if Subscription starts with a capital letter. When using graphql server and graphql-tools, there is no such error 🤔

Debug Information

From docs, capitalize subscription first letter:

roots: {
  Subscription: {
    greetings: async function* sayHiIn5Languages() {
      for (const hi of ['Hi', 'Bonjour', 'Hola', 'Ciao', 'Zdravo']) {
        yield { greetings: hi }
      }
    }
  }
}

Further Information

Trying to move from deprecated subscriptions-transport-ws 🙈

[enisdenjo]

Yeah, there should be a more communicative error message there… I guess an issue for Altair. Thanks for sharing!

My suggestion on auth is in the “ws server and client auth usage with token expiration, validation and refresh” recipe. Do check it out. 😄

[enisdenjo]

The roots object expects lowercase operation names. Please read the documentation about the roots option.

On how the roots work, the detected operation type root is put directly in the execute/subscribe rootValue argument: https://github.com/enisdenjo/graphql-ws/blob/4f11c8aeec092fac21bee6c9084f1e622b5e4a41/src/server.ts#L716

Furthermore, the roots option is just a convenience. You should absolutely use only the schema option as you attempted. However, when using makeExecutableSchema, you must nest the subscriptions iterator under the subscribe path:

const resolvers = {
  Subscription: {
-    greetings: async function* sayHiIn5Languages() {
-      for (const hi of ['Hi', 'Bonjour', 'Hola', 'Ciao', 'Zdravo']) {
-        yield { greetings: hi }
-      }
-    }
+    greetings: {
+      subscribe: async function* sayHiIn5Languages() {
+        for (const hi of ['Hi', 'Bonjour', 'Hola', 'Ciao', 'Zdravo']) {
+          yield { greetings: hi }
+        }
+      }
+    }
  }
}