Type ["null", "foo"] not converted correctly in "$ref"

[janjagusch]

I am trying to find a workaround for #26. This time, I tried creating a "nullable_schema" with type=["null", "object"] and then extending it in a different schema with type="object".

Input

{
    "allOf": [{"$ref": "#/nullable_schema"}, {"type": "object"}],
    "nullable_schema": {
        "type": ["null", "object"],
        "properties": {
            "my_string": {
                "type": "string"
            }
        },
        "required": ["my_string"],
        "additionalProperties": false
    }
}

I expected the output to be somehow like this. The extended schema was supposed to be left untouched and in the nullable schema the "type": "null" should have been casted to "nullable": true.

Expected Output

{
  "allOf": [
    {
      "$ref": "#/nullable_schema"
    },
    {
      "type": "object"
    }
  ],
  "nullable_schema": {
    "type": "object",
    "properties": {
      "my_string": {
        "type": "string"
      }
    },
    "required": [
      "my_string"
    ],
    "additionalProperties": false,
    "nullable": true
  }
}

As opposed to #26, this time the script did not crash. However, in the actual output the "type": "null" was not resolved. It was still "type": ["null", "object"].

Actual Output

{
  "allOf": [
    {
      "$ref": "#/nullable_schema"
    },
    {
      "type": "object"
    }
  ],
  "nullable_schema": {
    "type": [
      "null",
      "object"
    ],
    "properties": {
      "my_string": {
        "type": "string"
      }
    },
    "required": [
      "my_string"
    ],
    "additionalProperties": false
  }
}