fix: remove type field from schema if ref exists

asdf_pydantic/schema.py

@@ -1,5 +1,6 @@
 from typing import Optional
 
+from pydantic import WithJsonSchema
 from pydantic.json_schema import GenerateJsonSchema
 
 DEFAULT_ASDF_SCHEMA_REF_TEMPLATE = "#/definitions/{model}"
@@ -60,3 +61,12 @@ def generate(self, schema, mode="validation"):
         }
 
         return json_schema
+
+
+class WithAsdfSchema(WithJsonSchema):
+    def __init__(self, asdf_schema: dict, **kwargs):
+        super().__init__(asdf_schema, **kwargs)
+
+
+def AsdfTag(tag: str) -> WithAsdfSchema:
+    return WithAsdfSchema({"$ref": tag})

tests/examples/test_node.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import textwrap
+from typing import Annotated
 from unittest.mock import MagicMock, patch
 
 import asdf
@@ -14,6 +15,8 @@
 
 from asdf_pydantic import AsdfPydanticConverter, AsdfPydanticModel
 
+SelfAnnotatedAsdfNode = Annotated[AsdfTag]
+
 
 class AsdfNode(AsdfPydanticModel):
     """Model for a node in a graph/tree.