Refactor Eltex model to use centralized VLAN range expansion utility

- Replaced the internal `_expand_vlan_range` function in the `Eltex` class with the new `expand_vlan_range` utility from `utils.py` for improved code maintainability.
- Added a new configuration file `config.conf` for Eltex devices to facilitate testing.
- Introduced an expected output JSON file `config.expected.json` to validate the parsing of Eltex configurations against expected results.

oxi/interfaces/models/eltex.py

@@ -1,29 +1,6 @@
 from oxi.interfaces import register_parser
 from oxi.interfaces.base import BaseDevice
-
-
-def _expand_vlan_range(value: str | list[str]) -> list[str]:
-    if isinstance(value, list):
-        value = ",".join(str(item) for item in value)
-
-    result: list[str] = []
-    for part in value.split(","):
-        part = part.strip()
-        if not part:
-            continue
-        if "-" not in part:
-            result.append(part)
-            continue
-        start_s, end_s = part.split("-", 1)
-        try:
-            start, end = int(start_s), int(end_s)
-        except ValueError:
-            result.append(part)
-            continue
-        if start > end:
-            start, end = end, start
-        result.extend(str(vlan_id) for vlan_id in range(start, end + 1))
-    return result
+from oxi.interfaces.utils import expand_vlan_range
 
 
 @register_parser("eltex")
@@ -54,15 +31,8 @@ class Eltex(BaseDevice):
             tail = item.get("vlan_tail")
             if tail:
                 ids = [*ids, tail] if isinstance(ids, list) else f"{ids},{tail}"
-            for vid in _expand_vlan_range(ids):
+            for vid in expand_vlan_range(ids):
                 if vid in named_vlan:
                     continue
                 vlans.append({"vlan_id": vid})
         return vlans
-
-
-if __name__ == "__main__":
-    with open("./test_not_found.txt") as file:
-        data = file.read()
-    eltex = Eltex(data)
-    print(eltex.parse())