fix: update EmbeddingInput type, validate nested sub-elements, add tests

litellm/llms/vertex_ai/gemini_embeddings/batch_embed_content_transformation.py

@@ -216,6 +216,13 @@ def transform_openai_input_gemini_content(
 
     for element in input_list:
         if isinstance(element, list):
+            if not element:
+                raise ValueError("Nested input list must not be empty")
+            for sub in element:
+                if not isinstance(sub, str):
+                    raise ValueError(
+                        f"Elements inside a nested input list must be strings, got {type(sub)}"
+                    )
             parts = [
                 _build_part_for_input(sub, resolved_files=resolved_files)
                 for sub in element

litellm/types/llms/openai.py

@@ -103,7 +103,7 @@ FileTypes = Union[
 ]
 
 
-EmbeddingInput = Union[str, List[str]]
+EmbeddingInput = Union[str, List[Union[str, List[str]]]]
 
 
 class HttpxBinaryResponseContent(_HttpxBinaryResponseContent):

tests/test_litellm/llms/vertex_ai/gemini_embeddings/test_batch_embed_content_transformation.py

@@ -44,6 +44,12 @@ class TestIsMultimodalInput:
     def test_mixed_text_and_image(self):
         assert _is_multimodal_input(["hello", IMAGE_DATA_URI]) is True
 
+    def test_nested_list_is_multimodal(self):
+        assert _is_multimodal_input([["text_a", "text_b"]]) is True
+
+    def test_nested_list_with_image_is_multimodal(self):
+        assert _is_multimodal_input([["a red shoe", IMAGE_DATA_URI]]) is True
+
 
 class TestBuildPartForInput:
     def test_text_input(self):