tests: avoid side effects in assertions

Author: dkropachev

tests/unit/test_cluster.py

@@ -2464,7 +2464,8 @@ def test_initial_pool_clean_close_forces_host_recovery(self):
                 'cassandra.cluster.HostConnection',
                 side_effect=startup_error):
             session.add_or_renew_pool(host, is_host_addition=False)
-            assert not tasks.pop()()
+            task_result = tasks.pop()()
+            assert not task_result
 
         session.cluster.signal_connection_failure.assert_called_once_with(
             host,
@@ -2516,7 +2517,8 @@ def _on_down_locked(
                 'cassandra.cluster.HostConnection',
                 side_effect=startup_error):
             session.add_or_renew_pool(host, is_host_addition=False)
-            assert not tasks.pop()()
+            task_result = tasks.pop()()
+            assert not task_result
 
         assert session.cluster.down_calls == [
             (host, False, True, True),
@@ -2569,7 +2571,8 @@ def _on_down_locked(
                 'cassandra.cluster.HostConnection',
                 side_effect=startup_error):
             session.add_or_renew_pool(host, is_host_addition=False)
-            assert not tasks.pop()()
+            task_result = tasks.pop()()
+            assert not task_result
 
         assert calls == [
             ("public", True),
@@ -2615,7 +2618,8 @@ def on_down(
                 'cassandra.cluster.HostConnection',
                 side_effect=startup_error):
             session.add_or_renew_pool(host, is_host_addition=False)
-            assert not tasks.pop()()
+            task_result = tasks.pop()()
+            assert not task_result
 
         assert session.cluster.down_calls == [
             (host, False, True),
@@ -2638,7 +2642,8 @@ def test_stale_startup_close_does_not_mark_host_down(self):
                 side_effect=startup_error):
             session.add_or_renew_pool(host, is_host_addition=False)
             session.remove_pool(host)
-            assert not tasks.pop()()
+            task_result = tasks.pop()()
+            assert not task_result
 
         session.cluster.signal_connection_failure.assert_not_called()
 
@@ -2652,7 +2657,8 @@ def test_invalid_initial_keyspace_does_not_mark_host_down(self):
                 'cassandra.cluster.HostConnection',
                 side_effect=keyspace_error):
             session.add_or_renew_pool(host, is_host_addition=False)
-            assert not tasks.pop()()
+            task_result = tasks.pop()()
+            assert not task_result
 
         session.cluster.signal_connection_failure.assert_not_called()
 
@@ -2671,7 +2677,8 @@ def test_invalid_changed_keyspace_does_not_mark_host_down(self):
                 'cassandra.cluster.HostConnection',
                 return_value=new_pool):
             session.add_or_renew_pool(host, is_host_addition=False)
-            assert not tasks.pop()()
+            task_result = tasks.pop()()
+            assert not task_result
 
         session.cluster.on_down.assert_not_called()
         new_pool.shutdown.assert_called_once_with()
@@ -2743,7 +2750,8 @@ def test_pool_finishing_after_shutdown_is_closed_not_published(self):
                 return_value=new_pool):
             session.add_or_renew_pool(host, is_host_addition=False)
             session.shutdown()
-            assert tasks.pop()() is _STALE_POOL_ATTEMPT
+            task_result = tasks.pop()()
+            assert task_result is _STALE_POOL_ATTEMPT
 
         assert host not in session._pools
         new_pool.shutdown.assert_called_once_with()
@@ -2760,7 +2768,8 @@ def test_pool_finishing_after_host_down_is_closed_not_published(self):
             session.add_or_renew_pool(host, is_host_addition=False)
             host.set_down()
             session.on_down(host)
-            assert tasks.pop()() is _STALE_POOL_ATTEMPT
+            task_result = tasks.pop()()
+            assert task_result is _STALE_POOL_ATTEMPT
 
         assert host not in session._pools
         new_pool.shutdown.assert_called_once_with()
@@ -2779,7 +2788,8 @@ def test_unregistered_session_cannot_publish_pool_after_host_down(self):
             # concurrent DOWN cannot invalidate this attempt through
             # Session.on_down. Host state must fence publication itself.
             host.set_down()
-            assert tasks.pop()() is _STALE_POOL_ATTEMPT
+            task_result = tasks.pop()()
+            assert task_result is _STALE_POOL_ATTEMPT
 
         assert host not in session._pools
         new_pool.shutdown.assert_called_once_with()
@@ -2798,8 +2808,10 @@ def test_concurrent_renewals_publish_only_one_pool(self):
                 side_effect=[first_pool, second_pool]):
             session.add_or_renew_pool(host, is_host_addition=False)
             session.add_or_renew_pool(host, is_host_addition=False)
-            assert tasks.pop(0)() is True
-            assert tasks.pop(0)() is _STALE_POOL_ATTEMPT
+            task_result = tasks.pop(0)()
+            assert task_result is True
+            task_result = tasks.pop(0)()
+            assert task_result is _STALE_POOL_ATTEMPT
 
         assert session._pools[host] is first_pool
         old_pool.shutdown.assert_called_once_with()