fix(sdk_crashes): KeyError for multiple exceptions

src/sentry/utils/sdk_crashes/event_stripper.py

@@ -114,16 +114,32 @@ def strip_event_data(
     and the method only keeps SDK frames and system library frames.
     """
 
-    frames = get_path(event_data, "exception", "values", -1, "stacktrace", "frames")
-    if not frames:
+    last_exception = get_path(
+        event_data,
+        "exception",
+        "values",
+        -1,
+    )
+    if not last_exception:
         return {}
 
+    # The SDK crash detector only detects crashes based on the last exception value.
+    # Therefore, if the last exception doesn't contain a stacktrace something is off and
+    # we can drop the whole event.
+    last_exception_frames = get_path(last_exception, "stacktrace", "frames")
+    if not last_exception_frames:
+        return {}
+
+    event_data_copy = dict(event_data)
+
     # We strip the frames first because applying the allowlist removes fields that are needed
     # for deciding wether to keep a frame or not.
-    stripped_frames = _strip_frames(frames, sdk_crash_detector)
+    stripped_frames = _strip_frames(last_exception_frames, sdk_crash_detector)
+    last_exception["stacktrace"]["frames"] = stripped_frames
 
-    event_data_copy = dict(event_data)
-    event_data_copy["exception"]["values"][0]["stacktrace"]["frames"] = stripped_frames
+    # We only keep the last exception. We need to adopt the allowlist and stripping event data logic
+    # to support multiple exceptions.
+    event_data_copy["exception"]["values"] = [last_exception]
 
     stripped_event_data = _strip_event_data_with_allowlist(event_data_copy, EVENT_DATA_ALLOWLIST)
 

tests/sentry/utils/sdk_crashes/test_event_stripper.py

@@ -452,3 +452,77 @@ def test_strip_event_without_frames_returns_empty_dict(store_and_strip_event) ->
     stripped_event_data = store_and_strip_event(data=event_data)
 
     assert stripped_event_data == {}
+
+
+@django_db_all
+@pytest.mark.snuba
+def test_strip_event_with_multiple_exceptions_only_keep_last_one(store_and_strip_event) -> None:
+    event_data = get_crash_event()
+
+    exception_values = list(get_path(event_data, "exception", "values"))
+
+    crash_exception = dict(exception_values[0])
+    set_path(crash_exception, "type", value="SIGPIPE")
+    set_path(crash_exception, "value", value="Broken pipe")
+
+    exception_values.append(crash_exception)
+
+    set_path(event_data, "exception", "values", value=exception_values)
+
+    stripped_event_data = store_and_strip_event(data=event_data)
+
+    assert len(get_path(stripped_event_data, "exception", "values")) == 1
+
+    exception = get_path(stripped_event_data, "exception", "values", 0)
+    assert exception["type"] == "SIGPIPE"
+    assert "value" not in exception
+
+
+@django_db_all
+@pytest.mark.snuba
+def test_strip_event_with_multiple_exceptions_last_without_frames_discard_event(
+    store_and_strip_event,
+) -> None:
+    event_data = get_crash_event()
+
+    exception_values = list(get_path(event_data, "exception", "values"))
+
+    crash_exception = dict(exception_values[0])
+    set_path(crash_exception, "type", value="SIGPIPE")
+    set_path(crash_exception, "value", value="Broken pipe")
+    set_path(crash_exception, "stacktrace", value=None)
+    exception_values.append(crash_exception)
+
+    set_path(event_data, "exception", "values", value=exception_values)
+
+    stripped_event_data = store_and_strip_event(data=event_data)
+
+    assert stripped_event_data == {}
+
+
+@django_db_all
+@pytest.mark.snuba
+def test_strip_event_with_multiple_exceptions_first_without_frames_keeps_last_exception(
+    store_and_strip_event,
+) -> None:
+    event_data = get_crash_event()
+
+    exception_values = list(get_path(event_data, "exception", "values"))
+
+    crash_exception = dict(exception_values[0])
+    set_path(crash_exception, "type", value="SIGPIPE")
+    set_path(crash_exception, "value", value="Broken pipe")
+    exception_values.append(crash_exception)
+
+    # Remove the stacktrace from the first exception.
+    exception_values[0]["stacktrace"] = None
+
+    set_path(event_data, "exception", "values", value=exception_values)
+
+    stripped_event_data = store_and_strip_event(data=event_data)
+
+    assert len(get_path(stripped_event_data, "exception", "values")) == 1
+
+    exception = get_path(stripped_event_data, "exception", "values", 0)
+    assert exception["type"] == "SIGPIPE"
+    assert "value" not in exception