Add test for no Parent in _X_AMZN_TRACE_ID.

Author: purple4reina

datadog_lambda/tracing.py

@@ -89,7 +89,7 @@ def _convert_xray_sampling(xray_sampled):
     return SamplingPriority.USER_KEEP if xray_sampled else SamplingPriority.USER_REJECT
 
 
-def _get_xray_trace_context() -> Optional[Context]:
+def _get_xray_trace_context():
     if not is_lambda_context():
         return None
 

tests/test_tracing.py

@@ -14,6 +14,7 @@
 from datadog_lambda.constants import (
     SamplingPriority,
     TraceHeader,
+    TraceContextSource,
     XraySubsegment,
 )
 from datadog_lambda.tracing import (
@@ -854,6 +855,10 @@ def test_mixed_parent_context_when_merging(self):
         self.mock_activate.assert_called()
         self.mock_activate.assert_has_calls([call(expected_context)])
 
+    def test_set_dd_trace_py_root_no_span_id(self):
+        os.environ["_X_AMZN_TRACE_ID"] = "Root=1-5e272390-8c398be037738dc042009320"
+        set_dd_trace_py_root(TraceContextSource.EVENT, True)
+
 
 class TestAuthorizerInferredSpans(unittest.TestCase):
     def setUp(self):