Fix using validators set in __manifest__.py

E.g. you can use the validator 'is_file' to check if a config is a valid file

src/auto_archiver/core/orchestrator.py

@@ -207,9 +207,9 @@ class ArchivingOrchestrator:
                 should_store = kwargs.pop('should_store', False)
                 kwargs['dest'] = f"{module.name}.{kwargs.pop('dest', name)}"
                 try:
+                    kwargs['type'] = getattr(validators, kwargs.get('type', '__invalid__'))
+                except AttributeError:
                     kwargs['type'] = __builtins__.get(kwargs.get('type'), str)
-                except KeyError:
-                    kwargs['type'] = getattr(validators, kwargs['type'])
                 arg = group.add_argument(f"--{module.name}.{name}", **kwargs)
                 arg.should_store = should_store
 

src/auto_archiver/core/validators.py

@@ -1,7 +1,19 @@
-# used as validators for config values.
+# used as validators for config values. Should raise an exception if the value is invalid.
+from pathlib import Path
+import argparse
 
 def example_validator(value):
-    return "example" in value
+    if "example" not in value:
+        raise argparse.ArgumentTypeError(f"{value} is not a valid value for this argument")
+    return value
 
 def positive_number(value):
-    return value > 0
+    if value < 0:
+        raise argparse.ArgumentTypeError(f"{value} is not a positive number")
+    return value
+
+
+def valid_file(value):
+    if not Path(value).is_file():
+        raise argparse.ArgumentTypeError(f"File '{value}' does not exist.")
+    return value

src/auto_archiver/modules/csv_feeder/__manifest__.py

@@ -13,6 +13,9 @@
                 "default": None,
                 "help": "Path to the input file(s) to read the URLs from, comma separated. \
                         Input files should be formatted with one URL per line",
+                "required": True,
+                "type": "valid_file",
+                "nargs": "+",
             },
             "column": {
                 "default": None,