RFC: Enforce Interfaces having at least one implementing Object #1377
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It is unclear whether the spec validation from graphql/graphql-spec#424 as implemented by #1277 is what we want to have for the GraphQL Schema long term. This RFC lets us explore that option more, to see whether the breaking schema change is the right path forward.
mjmahone
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mjmahone
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PR: breaking change 💥
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I am generally supportive of having this.
A very common pattern is to create an interface first, start programming against that, then weeks later actually implement that interface. This is also a really nasty breaking change for large, existing schemas.
(#424)
I haven't noticed this pattern much in GraphQL. How would you code against an interface in GraphQL except for the pure schema design? Especially in GraphQL fields are more often only exposed as needed.
It is unfortunate that this change is breaking, but I believe it is improving the spec.
| if (possibleTypes.length === 0) { | ||
| context.reportError( | ||
| `Interface ${iface.name} must be implemented ` + | ||
| `by at least one Object type.`, |
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Should we maybe expand the error message a little?
Interface ${iface.name} must be implemented by at least one Object type. An interface that does not have any implementation can never be instantiated.
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This was reverted from the spec in graphql/graphql-spec#459. Closing this old PR, feel free to reopen if needed. |
It is unclear whether the spec validation from graphql/graphql-spec#424 as implemented by #1277 is what we want to have for the GraphQL Schema long term. This RFC lets us explore that option more, to see whether the breaking schema change is the right path forward.