nullable fields in swagger on node.js

RodH257 picture RodH257 · Jul 1, 2016 · Viewed 16.5k times · Source

I've spent a bunch of time trying to find a solution for creating swagger docs in Node.JS. The main library is swagger-node, in which you create a swagger yaml file and then add your controllers to it. It automatically provides swagger ui docs in your app and does validation on the request & response against the models you specify in your yaml.

This is neat, however I have a requirement that some fields I want to explicitly be able to return or accept null as a value, for instance:

{ 
  id: 123,
  description: "string",
  date_sent: null
}

I don't want to delete the date_sent key, I want to explicitly state it as null.

The swagger spec does not support anyOf which is how JSON schema normally does this I believe.

I'm wondering if there's a workaround? Perhaps some library available for node that has a x-nullable vendor specific flag you can add, or some way of specifying that my not-required fields should all be nullable.

Am I going to have to write something myself that takes my swagger file and then modifies it before the validator middleware runs, or is there some workaround someone can suggest?

Answer

Naz picture Naz · Mar 14, 2017

nullable field is supported in OpenAPI (fka Swagger) Specification v3.0.0, but not in v2.0. Nullable types are defined as follows:

# Can be string or null
type: string
nullable: true