Python: Handle url_citation annotations in FoundryChatClient streaming responses (#5071)

* Fix url_citation annotations dropped in streaming (#5029)

Add url_citation branch to the streaming annotation handler in
_parse_chunk_from_openai, mirroring the existing non-streaming path.
The handler creates an Annotation with type='citation', title, url,
and annotated_regions (TextSpanRegion), wrapped in Content.from_text.

Update test_streaming_annotation_added_with_unknown_type to use a
truly unknown type, and add new tests for url_citation (with and
without url).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Address review feedback for #5029: Python: [Bug]: url_citation annotations silently dropped in Foundry streaming (SharePoint grounding citations lost)

---------

Co-authored-by: Copilot <copilot@github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Evan Mattson <35585003+moonbox3@users.noreply.github.com>

python/packages/openai/tests/openai/test_openai_chat_client.py

@@ -2570,8 +2570,65 @@ def test_streaming_annotation_added_with_container_file_citation() -> None:
     assert content.additional_properties.get("end_index") == 50
 
 
-def test_streaming_annotation_added_with_unknown_type() -> None:
-    """Test streaming annotation added event with unknown type is ignored."""
+def test_streaming_annotation_added_with_url_citation() -> None:
+    """Test streaming annotation added event with url_citation type produces citation annotation."""
+    client = OpenAIChatClient(model="test-model", api_key="test-key")
+    chat_options = ChatOptions()
+    function_call_ids: dict[int, tuple[str, str]] = {}
+
+    mock_event = MagicMock()
+    mock_event.type = "response.output_text.annotation.added"
+    mock_event.annotation_index = 0
+    mock_event.annotation = {
+        "type": "url_citation",
+        "url": "https://example.sharepoint.com/sites/my-site/doc.pdf",
+        "title": "doc.pdf",
+        "start_index": 100,
+        "end_index": 112,
+    }
+
+    response = client._parse_chunk_from_openai(mock_event, chat_options, function_call_ids)
+
+    assert len(response.contents) == 1
+    content = response.contents[0]
+    assert content.type == "text"
+    assert content.annotations is not None
+    assert len(content.annotations) == 1
+    annotation = content.annotations[0]
+    assert annotation["type"] == "citation"
+    assert annotation["title"] == "doc.pdf"
+    assert annotation["url"] == "https://example.sharepoint.com/sites/my-site/doc.pdf"
+    assert annotation["additional_properties"]["annotation_index"] == 0
+    assert annotation["raw_representation"] == mock_event.annotation
+    assert annotation["annotated_regions"] is not None
+    assert len(annotation["annotated_regions"]) == 1
+    region = annotation["annotated_regions"][0]
+    assert region["type"] == "text_span"
+    assert region["start_index"] == 100
+    assert region["end_index"] == 112
+
+
+def test_streaming_annotation_added_with_url_citation_no_url() -> None:
+    """Test streaming annotation added event with url_citation but missing url is ignored."""
+    client = OpenAIChatClient(model="test-model", api_key="test-key")
+    chat_options = ChatOptions()
+    function_call_ids: dict[int, tuple[str, str]] = {}
+
+    mock_event = MagicMock()
+    mock_event.type = "response.output_text.annotation.added"
+    mock_event.annotation_index = 0
+    mock_event.annotation = {
+        "type": "url_citation",
+        "title": "doc.pdf",
+    }
+
+    response = client._parse_chunk_from_openai(mock_event, chat_options, function_call_ids)
+
+    assert len(response.contents) == 0
+
+
+def test_streaming_annotation_added_with_url_citation_no_indices() -> None:
+    """Test streaming annotation with url_citation that has url but no start_index/end_index."""
     client = OpenAIChatClient(model="test-model", api_key="test-key")
     chat_options = ChatOptions()
     function_call_ids: dict[int, tuple[str, str]] = {}
@@ -2582,11 +2639,36 @@ def test_streaming_annotation_added_with_unknown_type() -> None:
     mock_event.annotation = {
         "type": "url_citation",
         "url": "https://example.com",
+        "title": "Example",
+    }
+
+    response = client._parse_chunk_from_openai(mock_event, chat_options, function_call_ids)
+
+    assert len(response.contents) == 1
+    annotation = response.contents[0].annotations[0]
+    assert annotation["type"] == "citation"
+    assert annotation["title"] == "Example"
+    assert annotation["url"] == "https://example.com"
+    assert annotation["additional_properties"]["annotation_index"] == 0
+    assert "annotated_regions" not in annotation
+
+
+def test_streaming_annotation_added_with_unknown_type() -> None:
+    """Test streaming annotation added event with unknown type is ignored."""
+    client = OpenAIChatClient(model="test-model", api_key="test-key")
+    chat_options = ChatOptions()
+    function_call_ids: dict[int, tuple[str, str]] = {}
+
+    mock_event = MagicMock()
+    mock_event.type = "response.output_text.annotation.added"
+    mock_event.annotation_index = 0
+    mock_event.annotation = {
+        "type": "some_future_annotation_type",
+        "data": "test",
     }
 
     response = client._parse_chunk_from_openai(mock_event, chat_options, function_call_ids)
 
-    # url_citation should not produce HostedFileContent
     assert len(response.contents) == 0