Handle OpenTelemetry propagation failures

Author: Kludex

src/httpx2/httpx2/_opentelemetry.py

@@ -140,7 +140,13 @@ def start_request(self, request: Request) -> RequestTrace:
             span_context_manager=span_cm,
             start=time.perf_counter(),
         )
-        self._propagate.inject(request.headers)
+        try:
+            self._propagate.inject(request.headers)
+        except BaseException as exc:
+            trace.set_exception(exc)
+            trace.detach_current(type(exc), exc, exc.__traceback__)
+            trace.close()
+            raise
         return trace
 
 

tests/httpx2/test_opentelemetry.py

@@ -155,6 +155,32 @@ def handler(request: httpx2.Request) -> httpx2.Response:
     assert _duration_metric(capfire)["data"]["data_points"][0]["attributes"]["error.type"] == "httpx2.ConnectError"
 
 
+def test_opentelemetry_records_propagation_injection_exceptions(
+    capfire: CaptureLogfire,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    otel = otel_module.get_opentelemetry()
+    assert otel is not None
+
+    def inject(headers: httpx2.Headers) -> None:
+        raise RuntimeError("inject failed")
+
+    def handler(request: httpx2.Request) -> httpx2.Response:
+        pytest.fail("transport should not be called")  # pragma: no cover
+
+    monkeypatch.setattr(otel._propagate, "inject", inject)
+
+    transport = httpx2.MockTransport(handler)
+    with httpx2.Client(transport=transport) as client:
+        with pytest.raises(RuntimeError, match="inject failed"):
+            client.get("https://example.com/")
+
+    [span] = _httpx2_spans(capfire)
+    assert span.attributes["error.type"] == "builtins.RuntimeError"
+    assert span.status.status_code is StatusCode.ERROR
+    assert _duration_metric(capfire)["data"]["data_points"][0]["attributes"]["error.type"] == "builtins.RuntimeError"
+
+
 def test_opentelemetry_records_sync_body_read_exceptions(capfire: CaptureLogfire) -> None:
     def handler(request: httpx2.Request) -> httpx2.Response:
         return httpx2.Response(200, stream=FailingSyncStream())