fix(utils): guard against None fields in merge_embed_responses (#771)

When batching embed requests, later responses may have None for an
embedding field that the first response has set. The inner comprehension
now uses `(getattr(..., field) or [])` so None fields are treated as
empty rather than raising TypeError: 'NoneType' object is not iterable.

Fixes #770

Co-authored-by: Aegis Dev <devteamaegis@users.noreply.github.com>
Co-authored-by: fern-support <126544928+fern-support@users.noreply.github.com>

Author: devteamaegis

src/cohere/utils.py

@@ -228,7 +228,7 @@ def merge_embed_responses(responses: typing.List[EmbedResponse]) -> EmbedRespons
             field: [
                 embedding
                 for embedding_by_type in embeddings_by_type
-                for embedding in getattr(embedding_by_type, field)
+                for embedding in (getattr(embedding_by_type, field) or [])
             ]
             for field in fields
         }

tests/test_embed_utils.py

@@ -189,6 +189,16 @@ def test_merge_embeddings_floats(self) -> None:
             )
         ))
 
+    def test_merge_embeddings_by_type_with_none_field_in_later_response(self) -> None:
+        resp1 = EmbeddingsByTypeEmbedResponse(
+            response_type="embeddings_by_type", id="1",
+            embeddings=EmbedByTypeResponseEmbeddings(float_=[[1.0, 2.0]]))
+        resp2 = EmbeddingsByTypeEmbedResponse(
+            response_type="embeddings_by_type", id="2",
+            embeddings=EmbedByTypeResponseEmbeddings(float_=None))
+        result = merge_embed_responses([resp1, resp2])
+        self.assertEqual(result.embeddings.float_, [[1.0, 2.0]])  # type: ignore
+
     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