🐛 FIX: Initialising a Node with a User (#4977)

The `Node` constructor allows for a specific user to be set other
than the current default, except this wasn't actually working. The bug
has been fixed and a test added.

Cherry-pick: f4f543c

aiida/manage/tests/pytest_fixtures.py

@@ -70,6 +70,13 @@ def clear_database_before_test(aiida_profile):
     yield
 
 
+@pytest.fixture(scope='class')
+def clear_database_before_test_class(aiida_profile):
+    """Clear the database before a test class."""
+    aiida_profile.reset_db()
+    yield
+
+
 @pytest.fixture(scope='function')
 def temporary_event_loop():
     """Create a temporary loop for independent test case"""

aiida/orm/nodes/node.py

@@ -185,7 +185,7 @@ def __init__(
             raise ValueError('the computer is not stored')
 
         computer = computer.backend_entity if computer else None
-        user = user.backend_entity if user else User.objects(backend).get_default()
+        user = user if user else User.objects(backend).get_default()
 
         if user is None:
             raise ValueError('the user cannot be None')