move circular group association validation to view

awx/main/tests/functional/api/test_group.py

@@ -0,0 +1,15 @@
+import pytest
+
+from awx.api.versioning import reverse
+
+from awx.main.models import Group
+
+
+@pytest.mark.django_db
+def test_cyclical_association_prohibited(post, inventory, admin_user):
+    parent = Group.objects.create(inventory=inventory, name='parent_group')
+    child = parent.children.create(inventory=inventory, name='child_group')
+    # Attempt to make parent a child of the child
+    url = reverse('api:group_children_list', kwargs={'pk': child.id})
+    response = post(url, dict(id=parent.id), admin_user, expect=400)
+    assert 'cyclical' in response.data['error'].lower()