Add back origin_is_union()

Viicos · Viicos · commit 2b213409b700 · 2025-02-28T15:12:56.000+01:00
pydantic-settings relies on it.
diff --git a/pydantic/_internal/_typing_extra.py b/pydantic/_internal/_typing_extra.py
@@ -182,6 +182,27 @@ def is_namedtuple(tp: Any, /) -> bool:
     return lenient_issubclass(tp, tuple) and hasattr(tp, '_fields')
 
 
+# TODO In 2.12, delete this function. It is currently defined only to not break
+# pydantic-settings which relies on it:
+_t_union = typing.Union
+_te_union = typing_extensions.Union
+
+_t_union = typing.Union
+_te_union = typing_extensions.Union
+
+if sys.version_info >= (3, 10):
+
+    def origin_is_union(tp: Any, /) -> bool:
+        """Return whether the provided argument is the `Union` special form or the `UnionType`."""
+        return tp is _t_union or tp is _te_union or tp is types.UnionType
+
+else:
+
+    def origin_is_union(tp: Any, /) -> bool:
+        """Return whether the provided argument is the `Union` special form."""
+        return tp is _t_union or tp is _te_union
+
+
 def is_generic_alias(tp: Any, /) -> bool:
     return isinstance(tp, (types.GenericAlias, typing._GenericAlias))  # pyright: ignore[reportAttributeAccessIssue]
 
