properly clear context

sdk/core/azure-core/azure/core/tracing/ext/opencensus_span.py

@@ -15,7 +15,7 @@
     TYPE_CHECKING = False
 
 if TYPE_CHECKING:
-    from typing import Dict, Optional, Union, TypeVar
+    from typing import Dict, Optional, Union
 
     from azure.core.pipeline.transport import HttpRequest, HttpResponse
 
@@ -83,7 +83,10 @@ def to_header(self):
         temp_headers = {}
         if tracer_from_context is not None:
             ctx = tracer_from_context.span_context
-            temp_headers = tracer_from_context.propagator.to_headers(ctx)
+            try:
+                temp_headers = tracer_from_context.propagator.to_headers(ctx)
+            except AttributeError:
+                pass
         return temp_headers
 
     def add_attribute(self, key, value):

sdk/core/azure-core/tests/test_tracing_context.py

@@ -22,6 +22,7 @@ def __init__(self, environ={}, tracer_to_use=None):
 
     def __enter__(self):
         self.orig_sdk_context_span = tracing_context.current_span.get()
+        tracing_context.current_span.clear()
         settings.tracing_implementation.set_value(self.tracer_to_use)
         self.os_env.start()
         return self

sdk/core/azure-core/tests/tracing_common.py

@@ -19,6 +19,7 @@
 from opencensus.trace.samplers import AlwaysOnSampler
 from opencensus.trace.base_exporter import Exporter
 from collections import defaultdict
+from opencensus.trace import execution_context
 
 try:
     from unittest import mock
@@ -39,6 +40,8 @@ def __enter__(self):
         self.orig_tracer = OpenCensusSpan.get_current_tracer()
         self.orig_current_span = OpenCensusSpan.get_current_span()
         self.orig_sdk_context_span = tracing_context.current_span.get()
+        execution_context.clear()
+        tracing_context.current_span.clear()
         if self.tracer_to_use is not None:
             settings.tracing_implementation.set_value(self.tracer_to_use)
         if self.should_only_propagate is not None:
@@ -81,7 +84,4 @@ def export(self, span_datas):
     def build_tree(self):
         for node in self._all_nodes:
             if node.span_data.span_id in self.parent_dict:
-                node.children = sorted(
-                    self.parent_dict[node.span_data.span_id],
-                    key=lambda x: x.span_data.start_time,
-                )
+                node.children = sorted(self.parent_dict[node.span_data.span_id], key=lambda x: x.span_data.start_time)