VLANGroup: Single VLAN IDs render as n-n after save

[pheus]

NetBox Edition

NetBox Community

NetBox Version

v4.4.2

Python Version

3.12

Steps to Reproduce

1. Go to IPAM → VLAN Groups → Add.
2. Create a new VLAN group (any name/scope).
3. In VLAN ID Ranges, enter: 1-5,10,20-30.
4. Save, view the group (list & detail), then click Edit again.

Expected Behavior

The single VLAN ID 10 remains displayed as 10 (i.e., the value stays 1-5,10,20-30) across:

• The VLAN groups list/table
• The group detail view
• The edit form field

Observed Behavior

After saving, the value is rendered as 1-5,10-10,20-30.
The single VLAN 10 is displayed as a range (10-10) in the list, detail view, and pre‑populated edit form.

Notes

• VLAN groups support multiple VID ranges; single VLAN IDs are valid inputs. However, the UI expands singletons to n-n when displaying the saved value.
• Proposal: When serializing VID ranges for display and when pre‑populating the edit form, collapse any range where start == end to a single integer. This keeps the canonical representation user‑friendly without changing storage semantics.

[pheus]

I’ve identified a root cause and I’m happy to open a PR if this report is accepted.

[arthanson]

I'll assign it to you @pheus, thanks!

[pheus]

It seems a newer version of ruff is flagging unused imports in files not touched by the PR. Would you prefer I:

1. add a separate lint: commit to clean them up, or
2. open a small follow‑up PR just for the ruff cleanup?

Happy to do either. Please advise.