fix(edge): zones_from_config skips malformed rows without raising (IndexError/non-list guard)

edge/zones.py

@@ -5,7 +5,10 @@ from edge.detectors.zone import Zone
 
 def zones_from_config(config: dict) -> list[Zone]:
     out: list[Zone] = []
-    for row in config.get("zones", []) or []:
+    rows = config.get("zones", []) or []
+    if not isinstance(rows, list):
+        return []
+    for row in rows:
         try:
             raw = row["polygon_json"]
             pts = json.loads(raw) if isinstance(raw, str) else raw
@@ -13,7 +16,7 @@ def zones_from_config(config: dict) -> list[Zone]:
             if len(polygon) < 3:
                 continue
             out.append(Zone(str(row["zone_id"]), str(row["level"]), polygon))
-        except (KeyError, ValueError, TypeError, json.JSONDecodeError):
+        except (KeyError, ValueError, TypeError, IndexError, json.JSONDecodeError):
             continue
     return out
 

tests/test_zones.py

@@ -19,3 +19,15 @@ def test_skips_malformed_row():
 def test_empty_config():
     assert zones_from_config({}) == []
     assert thresholds_from_config({}) == {}
+
+def test_skips_short_point_without_crashing():
+    cfg = {"zones": [
+        {"zone_id": "bad", "camera_id": "c", "level": "restricted", "polygon_json": "[[0,0],[9],[9,9]]"},
+        {"zone_id": "ok", "camera_id": "c", "level": "restricted", "polygon_json": "[[0,0],[9,0],[9,9]]"},
+    ]}
+    zones = zones_from_config(cfg)
+    # bad row skipped, good row survives -- function did not crash
+    assert [z.zone_id for z in zones] == ["ok"]
+
+def test_non_iterable_zones_returns_empty():
+    assert zones_from_config({"zones": 5}) == []