update sample rate in dsc

Author: sentrivana

sentry_sdk/scope.py

@@ -1043,6 +1043,13 @@ def start_transaction(
         sampling_context.update(custom_sampling_context)
         transaction._set_initial_sampling_decision(sampling_context=sampling_context)
 
+        # update the sample rate in the dsc
+        propagation_context = self.get_active_propagation_context()
+        if propagation_context:
+            dsc = propagation_context.dynamic_sampling_context
+            if dsc is not None:
+                dsc["sample_rate"] = str(transaction.sample_rate)
+
         if transaction.sampled:
             profile = Profile(
                 transaction.sampled, transaction._start_timestamp_monotonic_ns

sentry_sdk/tracing_utils.py

@@ -378,7 +378,7 @@ def __init__(
         self.parent_sampled = parent_sampled
         """Boolean indicator if the parent span was sampled.
         Important when the parent span originated in an upstream service,
-        because we watn to sample the whole trace, or nothing from the trace."""
+        because we want to sample the whole trace, or nothing from the trace."""
 
         self.dynamic_sampling_context = dynamic_sampling_context
         """Data that is used for dynamic sampling decisions."""

tests/tracing/test_sampling.py

@@ -211,7 +211,7 @@ def test_passes_parent_sampling_decision_in_sampling_context(
     assert sampling_context["parent_sampled"]._mock_wraps is parent_sampling_decision
 
 
-def test_passes_custom_samling_context_from_start_transaction_to_traces_sampler(
+def test_passes_custom_sampling_context_from_start_transaction_to_traces_sampler(
     sentry_init, DictionaryContaining  # noqa: N803
 ):
     traces_sampler = mock.Mock()