Fix OpenAI image generation with reasoning (#166827)

homeassistant/components/openai_conversation/entity.py

@@ -346,7 +346,9 @@ async def _transform_stream(  # noqa: C901 - This is complex, but better to have
                             id=event.item.id,
                             tool_name="web_search_call",
                             tool_args={
-                                "action": event.item.action.to_dict(),
+                                "action": event.item.action.to_dict()
+                                if event.item.action
+                                else None,
                             },
                             external=True,
                         )
@@ -360,6 +362,10 @@ async def _transform_stream(  # noqa: C901 - This is complex, but better to have
                 }
                 last_role = "tool_result"
             elif isinstance(event.item, ImageGenerationCall):
+                if last_summary_index is not None:
+                    yield {"role": "assistant"}
+                    last_role = "assistant"
+                    last_summary_index = None
                 yield {"native": event.item}
                 last_summary_index = -1  # Trigger new assistant message on next turn
         elif isinstance(event, ResponseTextDeltaEvent):

tests/components/openai_conversation/test_ai_task.py

@@ -14,7 +14,7 @@ from homeassistant.core import HomeAssistant
 from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers import entity_registry as er, issue_registry as ir, selector
 
-from . import create_image_gen_call_item, create_message_item
+from . import create_image_gen_call_item, create_message_item, create_reasoning_item
 
 from tests.common import MockConfigEntry
 
@@ -247,8 +247,15 @@ async def test_generate_image(
 
     # Mock the OpenAI response stream
     mock_create_stream.return_value = [
-        create_image_gen_call_item(id="ig_A", output_index=0),
-        create_message_item(id="msg_A", text="", output_index=1),
+        (
+            *create_reasoning_item(
+                id="rs_A",
+                output_index=0,
+                reasoning_summary=[["The user asks me to generate an image"]],
+            ),
+            *create_image_gen_call_item(id="ig_A", output_index=1),
+            *create_message_item(id="msg_A", text="", output_index=2),
+        )
     ]
 
     with patch.object(