fix: make `key` in kafka msg binding validate as anyOf #466

derberg · 2023-12-11T10:58:02Z

Kafka binding for messages, in 0.4 version introduced Avro support for key - but JSON Schema is not properly modified

Kafka message binding -> https://github.com/asyncapi/bindings/tree/master/kafka#message-binding-object

so things like below should be allowed:

      bindings:
        kafka:
          key:
            $ref: "https://deploy-preview-921--asyncapi-website.netlify.app/resources/casestudies/adeo/CostingResponseKey.avsc"

Just go to https://studio.asyncapi.com/?url=https://raw.githubusercontent.com/asyncapi/spec/d78dcea70c9b094a3df72f9a4e811828cec778cc/examples/adeo-kafka-request-reply-asyncapi.yml and try to remove lines 242-245 all all suddenly validation stops failing

Where issue is coming from

This is what json schema for message binding says: https://github.com/asyncapi/spec-json-schemas/blob/master/bindings/kafka/0.4.0/message.json#L13-L21

current JSON Schema validates agains oneOf listed schemas, but problem is that these are reference object + json schema. JSON schema defines $ref property as well, so when in key you put $ref, it is then valid against both schemas listed under oneOf and yeah, it is an error.

I don't think there is a better solution than just using anyOf instead of oneOf 🤔

Also, such validation combination like the one I fix, is used in many other bindings, so also not sure but maybe I should propagate the fix everywhere?