codegen fails to produce anyOf/oneOf with a null type

[BrentMifsud]

Description

The code generator skips anyOf or oneOf that have nullable listed:

warning: Schema "null" is not supported, reason: "schema type", skipping [context: foundIn=Operations.OperationName.Output.Ok.Body.JsonPayload.DataPayloadPayload (#/paths/path/to/resource/GET/responses/200/content/json/DataPayload)/my_type]

Reproduction

"my_type": {
    "anyOf": [
        {
            "$ref": "#/components/schemas/MyType"
        },
        {
            "type": "null"
        }
    ]
}

"my_type": {
    "oneOf": [
        {
            "$ref": "#/components/schemas/MyType"
        },
        {
            "type": "null"
        }
    ]
}

Package version(s)

Expected behavior

ideally it should produce an optional. But an enum would also work.

Environment

swift 6.2
Xcode 26.0 beta 6

Additional information

The only workaround I've found is to do something like this, but the library our back end is using to produce the openapi spec does not seem to support something like this:

"my_type": {
    "$ref": "#/components/schemas/MyType",
    "type": ["object", "null"]
},

[czechboy0]

Hi @BrentMifsud,

I believe this is a duplicate, we already have one or two issues tracking it, I believe you already commented on them as well.

This is known - I'd recommend removing any explicit null types from the OpenAPI doc, and instead just rely on the required property in your object schemas. If a property is present, it'll be non-optional. If it's absent, it'll be optional - and that'll handle automatically both the case where the field is missing from the JSON and if it's present as null. You don't need to explicitly allow null in the OpenAPI doc, in fact that causes the issue you're seeing.

[czechboy0]

In your example, I'd just use:

"my_type": {
    "$ref": "#/components/schemas/MyType"
},

[czechboy0]

Related, #419, #513.