non null list of non null list of…

[atomkirk]

non null list of non null list of…

[Jayshua]

Looks like you have a list of nothing?

"ofType": {
   "kind": "LIST",
   "name": null
}

[dillonkearns]

It looks like the GraphQL schema is returning an invalid response.

The GraphQL Spec describes it here https://spec.graphql.org/draft/#sec-The-__Type-Type.Non-Null

It says that for NON_NULL types:

• kind must return __TypeKind.NON_NULL.
• ofType must return a type of any kind except Non-Null.
• All other fields must return null.

(Emphasis added to relevant section). So it looks like it's a bug with the library or server-side framework.

[atomkirk]

ahhhh

ok, I see it now. yep, the server lib shouldn't allow that

[dillonkearns]

ok, I see it now. yep, the server lib shouldn't allow that

Right, yeah it's just an extra type wrapper that doesn't add any meaning, which is why the GraphQL Spec disallows it. Let me know what the root turns out to be and what you find, I'm curious whether it's from a user-defined double-non-null, or just the server framework (or a plugin) adding the double non-null.

[atomkirk]

the double non-null was my own code. But now that I've fixed that, I think the

"ofType": {
   "kind": "LIST",
   "name": null
}

is a bug in the server lib. if i remove the non_null decorators, it works

[dillonkearns]

Gotcha, thanks for the info! It might be nice to improve the error message in this particular case, too. Something like:

I found a double non-null. This should probably be a single non-null, maybe check if your types have a redundant non-null somewhere? See https://spec.graphql.org/June2018/#sec-Type-Kinds.Non-Null