chore: rebase on main, clean up test imports, add dev deps for local e2e testing

- Rebased propagate-through-non-sdk-spans onto main, resolving conflicts
  in auto_instrument.py and test_auto_instrument.py
- Removed unused imports (copy_context, call) from test file; applied ruff
  formatting (long dict literal and assert message)
- Added litellm, langchain, langchain-community as dev deps so the local
  end-to-end test script (hack/test_propagation.py) can run without
  polluting the main dep tree
- Fixed ty type error: use getattr() to access span.attributes since the
  Span interface does not declare that attribute (only ReadableSpan does)

Author: jeanscherf

pyproject.toml

@@ -50,6 +50,9 @@ dev = [
     "starlette>=0.40.0",
     "anyio>=3.6.2",
     "httpx>=0.27.0",
+    "litellm==1.80.13",
+    "langchain>=1.2.15",
+    "langchain-community>=0.4.1",
 ]
 
 [tool.pytest.ini_options]

src/sap_cloud_sdk/core/telemetry/auto_instrument.py

@@ -120,7 +120,9 @@ def _set_baggage_processor():
     logger.info("Registered BaggageSpanProcessor for extension attribute propagation")
 
     provider.add_span_processor(PropagatedAttributesSpanProcessor())
-    logger.info("Registered PropagatedAttributesSpanProcessor for ContextVar attribute propagation")
+    logger.info(
+        "Registered PropagatedAttributesSpanProcessor for ContextVar attribute propagation"
+    )
 
 
 def _register_middleware_processors(middlewares: list[TelemetryMiddleware]) -> None:

src/sap_cloud_sdk/core/telemetry/propagated_attributes_processor.py

@@ -30,7 +30,7 @@ def on_start(self, span: Span, parent_context: Optional[Context] = None) -> None
         if not propagated:
             return
         try:
-            existing = span.attributes or {}
+            existing = getattr(span, "attributes", None) or {}
             for key, value in propagated.items():
                 if key not in existing:
                     span.set_attribute(key, value)

tests/core/unit/telemetry/test_propagated_attributes_processor.py

@@ -1,8 +1,7 @@
 """Tests for PropagatedAttributesSpanProcessor."""
 
 import threading
-from contextvars import copy_context
-from unittest.mock import MagicMock, call
+from unittest.mock import MagicMock
 
 import pytest
 
@@ -43,7 +42,9 @@ def test_injects_propagated_attrs_into_span_with_no_existing_attrs(self):
         assert span.set_attribute.call_count == 2
 
     def test_does_not_override_attrs_already_present_on_span(self):
-        _propagated_attrs_var.set({"gen_ai.request.model": "override", "custom.key": "val"})
+        _propagated_attrs_var.set(
+            {"gen_ai.request.model": "override", "custom.key": "val"}
+        )
         span = _make_recording_span(existing_attrs={"gen_ai.request.model": "gpt-4"})
 
         self.processor.on_start(span, None)
@@ -121,4 +122,6 @@ def run_in_fresh_context():
         t.start()
         t.join()
 
-        assert results == [0], "No attrs should be injected in the isolated thread context"
+        assert results == [0], (
+            "No attrs should be injected in the isolated thread context"
+        )