Ignore empty text alongside tool calls when streaming from Ollama (pydantic#2286)

Author: DouweM

pydantic_ai_slim/pydantic_ai/models/openai.py

@@ -1003,7 +1003,7 @@ async def _get_event_iterator(self) -> AsyncIterator[ModelResponseStreamEvent]:
 
             # Handle the text part of the response
             content = choice.delta.content
-            if content is not None:
+            if content:
                 yield self._parts_manager.handle_text_delta(vendor_part_id='content', content=content)
 
             # Handle reasoning part of the response, present in DeepSeek models

tests/models/test_deepseek.py

@@ -87,6 +87,6 @@ async def test_deepseek_model_thinking_stream(allow_model_requests: None, deepse
                 200: PartDeltaEvent(index=1, delta=TextPartDelta(content_delta=' there')),
                 201: PartDeltaEvent(index=1, delta=TextPartDelta(content_delta='!')),
             },
-            length=211,
+            length=210,
         )
     )

tests/models/test_openai.py

@@ -574,6 +574,42 @@ async def test_stream_native_output(allow_model_requests: None):
         assert result.is_complete
 
 
+async def test_stream_tool_call_with_empty_text(allow_model_requests: None):
+    stream = [
+        chunk(
+            [
+                ChoiceDelta(
+                    content='',  # Ollama will include an empty text delta even when it's going to call a tool
+                    tool_calls=[
+                        ChoiceDeltaToolCall(
+                            index=0, function=ChoiceDeltaToolCallFunction(name='final_result', arguments=None)
+                        )
+                    ],
+                ),
+            ]
+        ),
+        struc_chunk(None, '{"first": "One'),
+        struc_chunk(None, '", "second": "Two"'),
+        struc_chunk(None, '}'),
+        chunk([]),
+    ]
+    mock_client = MockOpenAI.create_mock_stream(stream)
+    m = OpenAIModel('gpt-4o', provider=OpenAIProvider(openai_client=mock_client))
+    agent = Agent(m, output_type=[str, MyTypedDict])
+
+    async with agent.run_stream('') as result:
+        assert not result.is_complete
+        assert [c async for c in result.stream(debounce_by=None)] == snapshot(
+            [
+                {'first': 'One'},
+                {'first': 'One', 'second': 'Two'},
+                {'first': 'One', 'second': 'Two'},
+                {'first': 'One', 'second': 'Two'},
+            ]
+        )
+    assert await result.get_output() == snapshot({'first': 'One', 'second': 'Two'})
+
+
 async def test_no_content(allow_model_requests: None):
     stream = [chunk([ChoiceDelta()]), chunk([ChoiceDelta()])]
     mock_client = MockOpenAI.create_mock_stream(stream)