fix(pydantic v1): more robust ModelField.annotation check (openai#2163)

Konnor-Young · Konnor Young · RobertCraigie · stainless-app[bot] · commit 6a2dfbb86c24 · 2025-04-23T17:32:49.000+01:00
---------

Co-authored-by: Konnor Young &lt;konnoryoung@ip-192-168-1-39.us-west-1.compute.internal&gt;
Co-authored-by: Robert Craigie &lt;robert@craigie.dev&gt;
diff --git a/src/openai/_models.py b/src/openai/_models.py
@@ -651,8 +651,8 @@ def _build_discriminated_union_meta(*, union: type, meta_annotations: tuple[Any,
                 # Note: if one variant defines an alias then they all should
                 discriminator_alias = field_info.alias
 
-                if field_info.annotation and is_literal_type(field_info.annotation):
-                    for entry in get_args(field_info.annotation):
+                if (annotation := getattr(field_info, 'annotation', None)) and is_literal_type(annotation):
+                    for entry in get_args(annotation):
                         if isinstance(entry, str):
                             mapping[entry] = variant
 
