feat(falcon): Set name and source on request span when streaming (#6562)

Call `Scope.set_transaction_name()` on the current scope in a `process_resource` middleware function (since the route is resolved when `process_resource` runs).
This ensures that the span name and the `sentry.span.source` attribute are set on the segment span when the streaming trace lifecycle is enabled.

Author: alexander-alderman-webb

sentry_sdk/integrations/falcon.py

@@ -5,6 +5,7 @@
 from sentry_sdk.integrations._wsgi_common import RequestExtractor
 from sentry_sdk.integrations.wsgi import SentryWsgiMiddleware
 from sentry_sdk.tracing import SOURCE_FOR_STYLE
+from sentry_sdk.tracing_utils import has_span_streaming_enabled
 from sentry_sdk.utils import (
     capture_internal_exceptions,
     ensure_integration_enabled,
@@ -104,6 +105,25 @@ def process_request(
         scope._name = "falcon"
         scope.add_event_processor(_make_request_event_processor(req, integration))
 
+    def process_resource(
+        self, req: "Any", resp: "Any", resource: "Any", params: "Any"
+    ) -> None:
+        """
+        Sets the segment name and source as the route is resolved when this runs.
+        """
+        client = sentry_sdk.get_client()
+        integration = client.get_integration(FalconIntegration)
+        if integration is None or not has_span_streaming_enabled(client.options):
+            return
+
+        name_for_style = {
+            "uri_template": req.uri_template,
+            "path": req.path,
+        }
+        name = name_for_style[integration.transaction_style]
+        source = sentry_sdk.traces.SOURCE_FOR_STYLE[integration.transaction_style]
+        sentry_sdk.set_transaction_name(name, source)
+
 
 TRANSACTION_STYLE_VALUES = ("uri_template", "path")
 

tests/integrations/falcon/test_falcon.py

@@ -121,24 +121,36 @@ def test_transaction_style(
     integration = FalconIntegration(transaction_style=transaction_style)
     sentry_init(
         integrations=[integration],
+        traces_sample_rate=1.0,
         _experiments={"trace_lifecycle": "stream" if span_streaming else "static"},
     )
 
     client = make_client()
     if span_streaming:
         items = capture_items("event")
+        items = capture_items("event", "span")
 
         response = client.simulate_get(url)
         assert response.status == falcon.HTTP_200
 
-        (event,) = (item.payload for item in items)
+        (event,) = (item.payload for item in items if item.type == "event")
+
+        sentry_sdk.flush()
+        spans = [item.payload for item in items if item.type == "span"]
+        spans = [span for span in spans if span["name"] == expected_transaction]
+        assert len(spans) == 1
+        assert spans[0]["attributes"]["sentry.span.source"] == expected_source
     else:
         events = capture_events()
 
         response = client.simulate_get(url)
         assert response.status == falcon.HTTP_200
 
-        (event,) = events
+        (event, transaction) = events
+
+        assert transaction["transaction"] == expected_transaction
+        assert transaction["transaction_info"] == {"source": expected_source}
+
     assert event["transaction"] == expected_transaction
     assert event["transaction_info"] == {"source": expected_source}