Provide a way to clear the tracer from the tests.

Author: carlosalberto

sqlalchemy_opentracing/__init__.py

@@ -100,6 +100,13 @@ def unregister_engine(obj):
     remove(obj, 'after_cursor_execute', _engine_after_cursor_handler)
     remove(obj, 'handle_error', _engine_error_handler)
 
+def _clear_tracer():
+    '''
+    Set the tracer to None. For test cases usage.
+    '''
+    global g_tracer
+    g_tracer = None
+
 def _can_operation_be_traced(conn, stmt_obj):
     '''
     Get whether an operation can be traced, depending on its

tests/test_api.py

@@ -17,7 +17,7 @@ def setUp(self):
         )
 
     def tearDown(self):
-        sqlalchemy_opentracing.g_tracer = None
+        sqlalchemy_opentracing._clear_tracer()
 
     def test_init(self):
         tracer = DummyTracer()

tests/test_core.py

@@ -16,7 +16,7 @@ def setUp(self):
             Column('name', String),
         )
     def tearDown(self):
-        sqlalchemy_opentracing.g_tracer = None
+        sqlalchemy_opentracing._clear_tracer()
 
     def test_traced(self):
         tracer = DummyTracer()

tests/test_orm.py

@@ -22,7 +22,7 @@ def setUp(self):
         User.metadata.create_all(self.engine)
 
     def tearDown(self):
-        sqlalchemy_opentracing.g_tracer = None
+        sqlalchemy_opentracing._clear_tracer()
 
     def test_traced_simple(self):
         tracer = DummyTracer()