fix(client): Capture exceptions raised by before_send callbacks

sentry_sdk/client.py

@@ -1244,7 +1244,8 @@ def _capture_telemetry(
             serialized = telemetry._to_json()  # type: ignore[union-attr]
 
         if before_send is not None:
-            serialized = before_send(serialized, {})  # type: ignore[arg-type]
+            with capture_internal_exceptions():
+                serialized = before_send(serialized, {})  # type: ignore[arg-type]
 
             if ty in ("log", "metric"):
                 # Logs and metrics can be dropped in their respective

sentry_sdk/tracing.py

@@ -1204,7 +1204,10 @@ def _set_initial_sampling_decision(
             try:
                 sample_rate = client.options["traces_sampler"](sampling_context)
             except Exception:
-                logger.warning("[Tracing] traces_sampler raised; falling back to parent sample rate or traces_sample_rate", exc_info=True)
+                logger.warning(
+                    "[Tracing] traces_sampler raised; falling back to parent sample rate or traces_sample_rate",
+                    exc_info=True,
+                )
                 sample_rate = (
                     sampling_context["parent_sampled"]
                     if sampling_context["parent_sampled"] is not None

sentry_sdk/tracing_utils.py

@@ -1544,7 +1544,10 @@ def add_sentry_baggage_to_headers(
         stripped_existing_baggage + separator + sentry_baggage
     )
 
-def _get_fallback_sample_rate(client: "BaseClient", propagation_context: "PropagationContext") -> "Union[float, bool]":
+
+def _get_fallback_sample_rate(
+    client: "BaseClient", propagation_context: "PropagationContext"
+) -> "Union[float, bool]":
     if propagation_context.parent_sampled is not None:
         propagation_context_sample_rate = propagation_context._sample_rate()
 
@@ -1555,6 +1558,7 @@ def _get_fallback_sample_rate(client: "BaseClient", propagation_context: "Propag
     else:
         return client.options["traces_sample_rate"]
 
+
 def _make_sampling_decision(
     name: str,
     attributes: "Optional[Attributes]",
@@ -1601,18 +1605,25 @@ def _make_sampling_decision(
         try:
             sample_rate = client.options["traces_sampler"](sampling_context)
         except Exception:
-            logger.warning("[Tracing] traces_sampler raised; falling back to parent sample rate or traces_sample_rate", exc_info=True)
-            sample_rate = _get_fallback_sample_rate(client=client, propagation_context=propagation_context)
+            logger.warning(
+                "[Tracing] traces_sampler raised; falling back to parent sample rate or traces_sample_rate",
+                exc_info=True,
+            )
+            sample_rate = _get_fallback_sample_rate(
+                client=client, propagation_context=propagation_context
+            )
     else:
-        sample_rate = _get_fallback_sample_rate(client=client, propagation_context=propagation_context)
+        sample_rate = _get_fallback_sample_rate(
+            client=client, propagation_context=propagation_context
+        )
 
     # Validate whether the sample_rate we got is actually valid. Since
     # traces_sampler is user-provided, it could return anything.
     if not is_valid_sample_rate(sample_rate, source="Tracing"):
         logger.warning(f"[Tracing] Discarding {name} because of invalid sample rate.")
         return False, None, None, "sample_rate"
 
-    sample_rate = float(sample_rate)  # type: ignore[arg-type]
+    sample_rate = float(sample_rate)
     if not sample_rate:
         if traces_sampler_defined:
             reason = "traces_sampler returned 0 or False"

tests/test_logs.py

@@ -162,6 +162,32 @@ def _before_log(record, hint):
     assert before_log_called is True
 
 
+@minimum_python_37
+@pytest.mark.tests_internal_exceptions
+def test_logs_before_send_log_raises_does_not_crash_application(
+    sentry_init, capture_items
+):
+    def _before_log(record, hint):
+        raise ValueError("before_send_log error")
+
+    sentry_init(
+        enable_logs=True,
+        before_send_log=_before_log,
+    )
+    items = capture_items("log")
+
+    sentry_sdk.logger.error("This is an error log...")
+
+    get_client().flush()
+    logs = [item.payload for item in items]
+
+    # The exception in before_send_log is swallowed and the original,
+    # unmodified log is sent.
+    assert len(logs) == 1
+    assert logs[0]["body"] == "This is an error log..."
+    assert logs[0]["attributes"]["sentry.severity_text"] == "error"
+
+
 @minimum_python_37
 def test_logs_attributes(sentry_init, capture_items):
     """

tests/test_metrics.py

@@ -247,6 +247,29 @@ def _before_metric(record, hint):
     assert before_metric_called
 
 
+@pytest.mark.tests_internal_exceptions
+def test_metrics_before_send_raises_does_not_crash_application(
+    sentry_init, capture_items
+):
+    def _before_metric(record, hint):
+        raise ValueError("before_send_metric error")
+
+    sentry_init(
+        before_send_metric=_before_metric,
+    )
+    items = capture_items("trace_metric")
+
+    sentry_sdk.metrics.count("test.keep", 1)
+
+    get_client().flush()
+
+    # The exception in before_send_metric is swallowed and the original,
+    # unmodified metric is sent.
+    metrics = [item.payload for item in items]
+    assert len(metrics) == 1
+    assert metrics[0]["name"] == "test.keep"
+
+
 def test_transport_format(sentry_init, capture_envelopes):
     sentry_init(server_name="test-server", release="1.0.0")
 

tests/tracing/test_span_streaming.py

@@ -356,6 +356,35 @@ def before_send_span(span, hint):
     assert not before_send_span_called
 
 
+@pytest.mark.tests_internal_exceptions
+def test_before_send_span_raises_does_not_crash_application(sentry_init, capture_items):
+    def before_send_span(span, hint):
+        raise ValueError("before_send_span error")
+
+    sentry_init(
+        traces_sample_rate=1.0,
+        _experiments={
+            "before_send_span": before_send_span,
+            "trace_lifecycle": "stream",
+        },
+    )
+
+    items = capture_items("span")
+
+    with sentry_sdk.traces.start_span(name="span"):
+        ...
+
+    sentry_sdk.get_client().flush()
+    spans = [item.payload for item in items]
+
+    # The exception in before_send_span is swallowed and the original,
+    # unmodified span is sent.
+    assert len(spans) == 1
+    (span,) = spans
+
+    assert span["name"] == "span"
+
+
 def test_span_attributes(sentry_init, capture_items):
     sentry_init(
         traces_sample_rate=1.0,