introduce new intersection type #941
Conversation
✅ Deploy Preview for graphql-spec-draft ready!
To edit notification comments on pull requests, go to your Netlify site settings. |
|
sorry, did I miss something, a lot maybe? - where's the discussion? Straight PR into spec? |
|
alternative to #939 |
This is a continuation of/alternative to the "unions implementing interfaces" work I presented at the last WG. |
yaacovCR
force-pushed
the
intersection
branch
2 times, most recently
from
cd8502c to
0a48c95
Compare
| @@ -343,6 +343,19 @@ UnionTypeExtension : | |||
| - extend union Name Directives[Const]? UnionMemberTypes | |||
| - extend union Name Directives[Const] | |||
|
|
|||
| IntersectionTypeDefinition : Description? intersection Name Directives[Const]? | |||
| IntersectionMemberTypes? | |||
There was a problem hiding this comment.
so IntersectionMemberTypes element is optional? we can have intersection with empty list of types?
There was a problem hiding this comment.
It is same as Union it could be extended later. So valid to be empty initially in sdl. When validated, it has to be non/empty if I recall correctly, just like unions. But we do allow an intersection with non empty list of member types and currently empty list of possible types due to conflict.
Just like interfaces without implementing types are allowed. I believe :)
| claims it returns an Intersection type, it will return only types that are | ||
| contained within all of the Intersections's Unions and types that implement all | ||
| of the Intersection's Interfaces. | ||
|
|
There was a problem hiding this comment.
- what is Intersection's Unions? in the grammar rule you mention IntersectionMemberTypes
- so... if at runtime field resolver returns a value of type that IS one of union types but does not implement one of interfaces - then what? it is replaced with null? what if field is not nullable? Hell confusing
There was a problem hiding this comment.
At runtime, only concrete object types can be returned as the actual type just like with any other abstract type.
There was a problem hiding this comment.
And yes, an intersection's unions are its member types that are unions. I copied the grammar from unions where even though object types are the only currently allowed member types, that is not specified at the grammar level, it's specified only as part of validation.
There was a problem hiding this comment.
If a non possible type is returned at runtime you get the same error as if you return a non implementing type when using an interface or an object type not in the Union.
In the implementation changes, there was no need to directly touch Execution because the only thing that changes is what goes on in the isSubType method
|
Summary of discussion from WG https://github.com/graphql/graphql-wg/blob/main/agendas/2022/2022-05-05.md :
The action item will then be to move forward as possible with #939 . Immediate next steps is to refine the implementation at graphql/graphql-js#3527 with further checking for all the necessary validation and test changes. |
see graphql/graphql-js#3550
[Edit by @benjie]: Explanation/discussion at graphql/graphql-wg#944