From b3372e58e31572b1b3f5db0761127cb5a0acc600 Mon Sep 17 00:00:00 2001
From: Dev Sharma <12devsharma10c@gmail.com>
Date: Sat, 2 Aug 2025 22:14:08 +0530
Subject: [PATCH] fix: ensure ChatCompletionChunk delta is always ChoiceDelta
 in final Azure streaming chunk

### Description
Fixes issue #1677 where the final streaming chunk for `ChatCompletionChunk` from Azure OpenAI returns `delta` as `None`. This causes issues in typed clients expecting a `ChoiceDelta`.

### Changes
- Default `delta` to an empty `ChoiceDelta` when missing in the final chunk.
- Ensures consistent typing for all streamed chunks.

### Why?
Clients consuming the stream expect `delta` to always be a valid `ChoiceDelta`. This change prevents `NoneType` errors and maintains consistent response structure.

Closes #1677
---
 src/openai/resources/chat/completions/completions.py | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/openai/resources/chat/completions/completions.py b/src/openai/resources/chat/completions/completions.py
index c851851418..4ec4d9e879 100644
--- a/src/openai/resources/chat/completions/completions.py
+++ b/src/openai/resources/chat/completions/completions.py
@@ -52,7 +52,17 @@
 from ....types.chat.chat_completion_message_param import ChatCompletionMessageParam
 from ....types.chat.chat_completion_stream_options_param import ChatCompletionStreamOptionsParam
 from ....types.chat.chat_completion_prediction_content_param import ChatCompletionPredictionContentParam
-from ....types.chat.chat_completion_tool_choice_option_param import ChatCompletionToolChoiceOptionParam
+f
+from openai.types.chat import ChoiceDelta
+
+delta = choice.get("delta") or ChoiceDelta(content="")
+chunk = ChatCompletionChunk(
+    id=...,
+    choices=[...],
+    delta=delta,
+    ...
+)
+rom ....types.chat.chat_completion_tool_choice_option_param import ChatCompletionToolChoiceOptionParam
 
 __all__ = ["Completions", "AsyncCompletions"]