Fix seeddb netbox-edit form so that empty function field will remove function info from netbox

changelog.d/2269.fixed.md

@@ -0,0 +1,3 @@
+Emptying the function field then clicking *Save* when editing a netbox
+now actually removes the function for that netbox (as opposed to
+silently ignoring the change).

python/nav/web/seeddb/page/netbox/edit.py

@@ -290,6 +290,8 @@ def netbox_do_save(form):
  else:
  func.value = function
  func.save()
+ elif function == '':
+ NetboxInfo.objects.filter(netbox=netbox, variable='function').delete()
 
  # Save the groups
  netboxgroups = form.cleaned_data['groups']

tests/integration/seeddb_test.py

@@ -6,7 +6,7 @@
 from mock import MagicMock
 
 from django.utils.encoding import smart_str
-from nav.models.manage import Netbox, Room
+from nav.models.manage import Netbox, Room, NetboxInfo
 from nav.web.seeddb.page.netbox.edit import netbox_edit, log_netbox_change
 from nav.web.seeddb.utils.delete import dependencies
 
@@ -110,3 +110,41 @@ def test_log_netbox_change_should_not_crash(admin_account, netbox):
  new.category_id = "OTHER"
 
  assert log_netbox_change(admin_account, old, new) is None
+
+
+def test_empty_function_field_in_netbox_edit_form_should_delete_respective_netboxinfo_instance(
+ netbox, db, client
+):
+ """
+ Empty function fields in the webform should cause the function's
+ corresponding NetboxInfo to be deleted; This is the correct thing
+ to do because NAV prefills user forms with previously assigned
+ values. Hence, if NAV receives a form with an empty function
+ string, this means the user has explicitly cleared the function
+ string.
+ """
+ url = reverse('seeddb-netbox-edit', args=(netbox.id,))
+
+ def post(func):
+ return client.post(
+ url,
+ follow=True,
+ data={
+ "ip": netbox.ip,
+ "room": netbox.room_id,
+ "category": netbox.category_id,
+ "organization": netbox.organization_id,
+ "function": func,
+ },
+ )
+
+ assert len(NetboxInfo.objects.filter(netbox=netbox, variable='function')) == 0
+ post("")
+ assert len(NetboxInfo.objects.filter(netbox=netbox, variable='function')) == 0
+ post("foo")
+ assert (
+ NetboxInfo.objects.filter(netbox=netbox, variable='function').get().value
+ == 'foo'
+ )
+ post("")
+ assert len(NetboxInfo.objects.filter(netbox=netbox, variable='function')) == 0