fix(utils): guard against None entries in sum_fields_if_not_none (#773)

When ApiMeta.billed_units is None (its default), merge_meta_field builds
a list containing None. The list comprehension in sum_fields_if_not_none
called getattr(obj, field) without checking if obj is None first, raising
AttributeError. Adding `obj is not None` before the getattr check fixes it.

Co-authored-by: Ishaan Samantray <ishaansamantray@mac.mynetworksettings.com>

Author: devteamaegis

src/cohere/utils.py

@@ -163,7 +163,7 @@ async def async_wait(
 
 
 def sum_fields_if_not_none(obj: typing.Any, field: str) -> Optional[int]:
-    non_none = [getattr(obj, field) for obj in obj if getattr(obj, field) is not None]
+    non_none = [getattr(obj, field) for obj in obj if obj is not None and getattr(obj, field) is not None]
     return sum(non_none) if non_none else None
 
 

tests/test_embed_utils.py

@@ -2,7 +2,7 @@
 
 from cohere import EmbeddingsByTypeEmbedResponse, EmbedByTypeResponseEmbeddings, ApiMeta, ApiMetaBilledUnits, \
     ApiMetaApiVersion, EmbeddingsFloatsEmbedResponse
-from cohere.utils import merge_embed_responses
+from cohere.utils import merge_embed_responses, sum_fields_if_not_none
 
 ebt_1 = EmbeddingsByTypeEmbedResponse(
     response_type="embeddings_by_type",
@@ -189,6 +189,12 @@ def test_merge_embeddings_floats(self) -> None:
             )
         ))
 
+    def test_sum_fields_if_not_none_with_none_entries(self) -> None:
+        # billed_units list may contain None when ApiMeta.billed_units is unset;
+        # sum_fields_if_not_none must skip None objects without raising AttributeError
+        result = sum_fields_if_not_none([None, ApiMetaBilledUnits(input_tokens=5), None], "input_tokens")
+        self.assertEqual(result, 5)
+
     def test_merge_partial_embeddings_floats(self) -> None:
         resp = merge_embed_responses([
             ebt_partial_1,