Enhance shift constraints validation and error handling in forms and templates

djangorota/rota/forms.py

@@ -663,6 +663,26 @@ class ShiftForm(forms.Form):
             parsed = json.loads(val)
             if not isinstance(parsed, list):
                 raise forms.ValidationError("Constraints must be a JSON list of constraint objects")
+            # Validate each constraint object for basic correctness
+            errors = []
+            for i, c in enumerate(parsed):
+                if not isinstance(c, dict):
+                    errors.append(f"Constraint #{i+1} must be an object")
+                    continue
+                name = c.get('name') or c.get('type')
+                if not name:
+                    errors.append(f"Constraint #{i+1} missing 'name'")
+                    continue
+                if name in ('pre', 'post'):
+                    opts = c.get('options', {}) or {}
+                    # days is now required: check top-level or under options
+                    days_val = c.get('days') if c.get('days') is not None else opts.get('days')
+                    if days_val is None:
+                        errors.append(
+                            f"Constraint #{i+1} ('{name}') requires a 'days' duration (number of days the constraint applies for)."
+                        )
+            if errors:
+                raise forms.ValidationError(errors)
             return parsed
         except forms.ValidationError:
             raise