asyncio.iscoroutinefunction was None in destructor (#643)

Author: robsdedude

neo4j/_async/driver.py

@@ -16,8 +16,6 @@
 # limitations under the License.
 
 
-import asyncio
-
 from .._async_compat.util import AsyncUtil
 from ..addressing import Address
 from ..api import READ_ACCESS
@@ -197,7 +195,7 @@ async def __aexit__(self, exc_type, exc_value, traceback):
         await self.close()
 
     def __del__(self):
-        if not asyncio.iscoroutinefunction(self.close):
+        if not AsyncUtil.is_async_code:
             self.close()
 
     @property

neo4j/_async_compat/util.py

@@ -45,6 +45,8 @@ async def callback(cb, *args, **kwargs):
 
     experimental_async = experimental
 
+    is_async_code = True
+
 
 class Util:
     iter = iter
@@ -61,3 +63,5 @@ def experimental_async(message):
         def f_(f):
             return f
         return f_
+
+    is_async_code = False

neo4j/_sync/driver.py

@@ -16,8 +16,6 @@
 # limitations under the License.
 
 
-import asyncio
-
 from .._async_compat.util import Util
 from ..addressing import Address
 from ..api import READ_ACCESS
@@ -197,7 +195,7 @@ def __exit__(self, exc_type, exc_value, traceback):
         self.close()
 
     def __del__(self):
-        if not asyncio.iscoroutinefunction(self.close):
+        if not Util.is_async_code:
             self.close()
 
     @property