z.nullable does not use schema references

[FelixZY]

I have a schema like this:

  parentVenue: z.nullable(ProfileReferenceDTOSchema).openapi({
    description:
      'A venue to which this venue belongs.\n\nFor example, the theoretical venue "Dance Palace" may be the parent venue of the venues "Indoors" and "Outdoors"',
  }),
  childVenues: z.array(ProfileReferenceDTOSchema).openapi({
    description:
      'The venues that belong to this venue.\n\nFor example, the theoretical venues "Indoors" and "Outdoors" may be child venues of the venue "Dance Palace"',
  }),

Which causes an annoying difference when rendered:

It seems the reason for this is that the openapi spec generated for z.array uses

"type": "array",
"items": {
  "$ref": "#/components/schemas/profiles.ProfileReferenceDTO"
},

whereas the openapi spec generated for z.nullable does not use $ref (tested for openapi 3.0.3 and 3.1.0):

"type": "object",
"nullable": true,
"properties": {
  "id": { "type": "string", "format": "uuid" },
  "name": { "type": "string" },
  "type": {
    "type": "string",
    "enum": ["organization", "individual", "venue"]
  },
  "images": {
    "$ref": "#/components/schemas/storage.ImageDTO"
  }
}

Would it be possible to get z.nullable to generate a $ref as well? Perhaps using oneOf?

[AGalabov]

@FelixZY thanks for bringing this up. nullables are tricky since they behave differently based on the chosen OpenApi version (3.0 or 3.1). I'll try and take a look asap, but right now we are hoping to release a new major version and I'll probably have to prioritize the feature requests of the other open issues slightly higher. Sorry for that, and I'll come back to you as soon as I can. In the mean time feel free to give it a go and open a PR yourself.

[AGalabov]

@FelixZY I took a look at your example. And actually we already support that. The result has allOf. However we've only currently done the required support on schema.nullable() and not on z.nullable(schema). I'll open a PR soon but you can also fix this on your end (functionally there shouldn't be any difference for you).

[AGalabov]

This turned out to be impossible with the current way of implementing such methods. Because of that I've just updated the README.md file with a note for it (that schema.nullable() should be used instead)