SchemaTypeChecker does not check interface extension field types

[ctrlcwho]

graphql-java/src/main/java/graphql/schema/idl/SchemaTypeChecker.java

Line 380 in d2ca93c

private void checkFieldTypesPresent(TypeDefinitionRegistry typeRegistry, List<GraphQLError> errors, TypeDefinition typeDefinition, List<FieldDefinition> fields) {

The SchemaTypeChecker class only checks type extension field types, not interface extension fields, this seems like inconsistent behavior.
To reproduce, simply run the following type registry through graphql.schema.idl.SchemaTypeChecker#checkTypeRegistry:

interface BaseType {
  id: String
}
extend interface BaseType {
  reference: OtherType
}

No error related to OtherType not existing within the type registry will be thrown, but when you make the interface into a type, the type registry checker will return a validation error.

[bbakerman]

When we first put the TypeDefinitionRegistry code in place, we put in a series of checks to make sure we had a consistent and correct schema - aka these rules.

Later we learnt that there are cases that can be really checked until you have a full schema so we started to check schema invariants the GraphqlSchema .build() code.

I guess my point of this story is - if this referenced OtherType can exist in GraphqlSchema form then its a bug.

However if after calling SchemaParser + SchemaGenerator there is an SchemaProblem throw by some part of the code then its not a bug, just not implemented all in SchemaTypeChecker

[github-actions]

Hello, this issue has been inactive for 60 days, so we're marking it as stale. If you would like to continue this discussion, please comment within the next 30 days or we'll close the issue.