fix(traces): keep a falsy status message set by before_span_send

A message of 0 or False was dropped, and one whose truth test raises took
the whole span with it. Only None now means no message, as in set_status.

Author: turnipdabeets

posthog/test/tracing/test_pipeline.py

@@ -879,6 +879,15 @@ def long_message(span):
         pipeline.start_span("a").end()
         assert queued(pipeline)[0].status.message == "mmmmm"
 
+    def test_keeps_a_falsy_status_message_the_hook_sets(self):
+        def zero_message(span):
+            span["status"] = {"code": "error", "message": 0}
+            return span
+
+        pipeline, _, _ = make(before_span_send=zero_message)
+        pipeline.start_span("a").end()
+        assert queued(pipeline)[0].status.message == "0"
+
     def test_a_status_message_whose_str_raises_keeps_the_span(self):
         class Hostile:
             def __str__(self):

posthog/tracing/_before_span_send.py

@@ -190,7 +190,8 @@ def _hook_status(value: Any, original: Optional[SpanStatus]) -> Optional[SpanSta
         return None
     if isinstance(value, Mapping) and value.get("code") in ("ok", "error"):
         message = value.get("message")
-        return SpanStatus(value["code"], safe_str(message) if message else None)
+        text = None if message is None else safe_str(message)
+        return SpanStatus(value["code"], text or None)
     # An unknown code would lose an error the span really had.
     log.debug("before_span_send set an unknown span status; keeping the original")
     return original