Instance value (null) not found in enum

[Geoffrey Wiseman]

Trying out swagger-request-validator and I’m getting:

{ 
  "messages" : [ {
    "key" : "validation.request.body.schema.allOf",
    "level" : "ERROR",
    "message" : "Instance failed to match all required schemas (matched only 0 out of 2)",
    "additionalInfo" : [ "/allOf/0: Instance type (null) does not match any allowed primitive type (allowed: [\"string\"])", "/allOf/0: Instance value (null) not found in enum (possible values: [\"TWENTY_PAY\",\"LIFE_PAY\"])", "/allOf/0: Instance type (null) does not match any allowed primitive type (allowed: [\"string\"])", "/allOf/1: Instance type (null) does not match any allowed primitive type (allowed: [\"object\"])" ],
    "context" : {
      "requestPath" : "/quotes",
      "apiRequestContentType" : "application/json",
      "location" : "REQUEST",
      "requestMethod" : "POST"
    }
  } ]
}

I've got an OpenAPI spec, the request has an enum, the property isn’t required … so why is swagger-request-validator complaining about a null?

[Geoffrey Wiseman]

Ah – wait; am I supposed to include null in the enum list even if the property isn’t required?

e.g:

https://github.com/epoberezkin/ajv/issues/824

[Geoffrey Wiseman]

Nope, can’t really do that in OpenAPI:

https://github.com/OAI/OpenAPI-Specification/issues/229

‌

Suggestions if I have an OpenAPI spec with nullable enums and I’d like to use this validator are welcome.

[Geoffrey Wiseman]

See also:
https://github.com/epoberezkin/ajv/issues/993

[Geoffrey Wiseman]

FWIW, I’m working around this for now by customizing Jackson within RestAssured to not submit properties (inclusion set to ignore nulls), in case anyone else hits this and there isn’t a validator solution yet.

[Sven Döring]

That a field can be null has to be specifically set on the interface definition.

In OpenAPI 3 it’s done with nullable (https://swagger.io/docs/specification/data-models/data-types/#null). In OpenAPI 2 / Swagger it’s a vendor extension with x-nullable.

[Geoffrey Wiseman]

Yeah, I think we moved to OAS 3 and added nullability since then; not sure what the right move would be in OAS 2, given that it’s a vendor extension?

[Sven Döring]

Just use x-nullable instead of nullable on the OAS2 definitions. That’s all.