SchemaDiff has no special/helpful handling for directives like @deprecated

[grrttedwards]

Version 11.0
Currently, SchemaDiff does not make any distinctions for changes which involve @deprecated directives. This may be intended, but I was considering a use case where this is important information for an automated service registry. For example, the following change generates no meaningful events:

type Query { foo: TypeA } 
-type TypeA { abc: String xyz: Int }
---
type Query { foo: TypeA } 
+type TypeA { abc: String @deprecated xyz: Int }

Output:

14:22:26.799 [main] INFO - Infos count: 9
14:22:26.807 [main] INFO - DifferenceEvent{ reasonMsg='Examining operation 'Query' ...', level=INFO, category=null, typeName='Query', typeKind=Operation, fieldName=null}
14:22:26.807 [main] INFO - DifferenceEvent{ reasonMsg='Examining type 'Query' ...', level=INFO, category=null, typeName='Query', typeKind=Object, fieldName=null}
14:22:26.807 [main] INFO - DifferenceEvent{ reasonMsg='	Examining field 'Query.foo' ...', level=INFO, category=null, typeName='Query', typeKind=Object, fieldName=foo}
14:22:26.807 [main] INFO - DifferenceEvent{ reasonMsg='Examining type 'TypeA' ...', level=INFO, category=null, typeName='TypeA', typeKind=Object, fieldName=null}
14:22:26.807 [main] INFO - DifferenceEvent{ reasonMsg='	Examining field 'TypeA.abc' ...', level=INFO, category=null, typeName='TypeA', typeKind=Object, fieldName=abc}
14:22:26.807 [main] INFO - DifferenceEvent{ reasonMsg='	Examining field 'TypeA.xyz' ...', level=INFO, category=null, typeName='TypeA', typeKind=Object, fieldName=xyz}
14:22:26.807 [main] INFO - DifferenceEvent{ reasonMsg='	Examining field 'TypeA.abc' ...', level=INFO, category=null, typeName='TypeA', typeKind=Object, fieldName=abc}
14:22:26.807 [main] INFO - DifferenceEvent{ reasonMsg='	Examining field 'TypeA.xyz' ...', level=INFO, category=null, typeName='TypeA', typeKind=Object, fieldName=xyz}
14:22:26.807 [main] INFO - DifferenceEvent{ reasonMsg='	Examining field 'Query.foo' ...', level=INFO, category=null, typeName='Query', typeKind=Object, fieldName=foo}
14:22:26.808 [main] WARN - Danger count: 0
14:22:26.808 [main] ERROR - Breakage count: 0

In addition, it would be desirable to see a special handling of a breaking change involving a deprecated field. In the case of the automated service registry I mentioned, it's possible to allow such a breaking change only if the service had deprecated the field in a previous version. For example:

type Query { foo: TypeA } 
-type TypeA { abc: String @deprecated xyz: Int }
---
type Query { foo: TypeA } 
+type TypeA { xyz: Int }

Reports only a standard BREAKING change

14:29:52.811 [main] INFO - Infos count: 8
14:29:52.814 [main] INFO - DifferenceEvent{ reasonMsg='Examining operation 'Query' ...', level=INFO, category=null, typeName='Query', typeKind=Operation, fieldName=null}
14:29:52.814 [main] INFO - DifferenceEvent{ reasonMsg='Examining type 'Query' ...', level=INFO, category=null, typeName='Query', typeKind=Object, fieldName=null}
14:29:52.814 [main] INFO - DifferenceEvent{ reasonMsg='	Examining field 'Query.foo' ...', level=INFO, category=null, typeName='Query', typeKind=Object, fieldName=foo}
14:29:52.814 [main] INFO - DifferenceEvent{ reasonMsg='Examining type 'TypeA' ...', level=INFO, category=null, typeName='TypeA', typeKind=Object, fieldName=null}
14:29:52.814 [main] INFO - DifferenceEvent{ reasonMsg='	Examining field 'TypeA.abc' ...', level=INFO, category=null, typeName='TypeA', typeKind=Object, fieldName=abc}
14:29:52.814 [main] INFO - DifferenceEvent{ reasonMsg='	Examining field 'TypeA.xyz' ...', level=INFO, category=null, typeName='TypeA', typeKind=Object, fieldName=xyz}
14:29:52.814 [main] INFO - DifferenceEvent{ reasonMsg='	Examining field 'TypeA.xyz' ...', level=INFO, category=null, typeName='TypeA', typeKind=Object, fieldName=xyz}
14:29:52.814 [main] INFO - DifferenceEvent{ reasonMsg='	Examining field 'Query.foo' ...', level=INFO, category=null, typeName='Query', typeKind=Object, fieldName=foo}
14:29:52.815 [main] WARN - Danger count: 0
14:29:52.815 [main] ERROR - Breakage count: 1
14:29:52.816 [main] ERROR - DifferenceEvent{ reasonMsg='The new API is missing the field 'TypeA.abc'', level=BREAKING, category=MISSING, typeName='TypeA', typeKind=Object, fieldName=abc}

[grrttedwards]

graphql-hive/graphql-inspector#287

Linking related issue from another similar tool.

[andimarek]

@grrttedwards I think this is simply missing so far. Do you think you could create a PR for that? that would be great.

[grrttedwards]

@andimarek I've been thinking about it; Could you briefly describe what you think a good way to handle this would be? A new schema difference level? Or just a new category? Because it's technically still breaking, but it's less severe if the field has been deprecated. I don't know if that warrants a new level between breaking and dangerous, or if it's just the existing dangerous.

[grrttedwards]

@andimarek Opened #1610

[andimarek]

closing because the the referenced PR is merged.