Strengthen types in Args

format.py

@@ -149,7 +149,7 @@ def get_country_name(
 parser = argparse.ArgumentParser(
     prog="format", description="format postcards with latex"
 )
-parser.add_argument("template", help="template to use", nargs="?", default="2card")
+parser.add_argument("template", help="template to use", nargs="?", type=Path, default="2card")
 parser.add_argument(
     "-o", "--origin", help="origin country code", default="us", type=iso_code
 )
@@ -179,7 +179,7 @@ parser.add_argument(
     "-a",
     "--address-file",
     default="addresses.csv",
-    type=str,
+    type=Path,
     help="CSV file containing addresses",
 )
 
@@ -187,7 +187,7 @@ parser.add_argument(
     "-i",
     "--content-path",
     default="content",
-    type=str,
+    type=Path,
     help="Directory containing content files",
 )
 
@@ -206,13 +206,13 @@ parser.add_argument("-w", "--watch", action="store_true", help="Watch input file
 
 
 class Args(argparse.Namespace):
-    template: str
+    template: Path
     origin: IsoCode
     language: IsoCode
     count: int
     skip: int
-    address_file: str
-    content_path: str
+    address_file: Path
+    content_path: Path
     no_content: bool
     dont_compile: bool
 
@@ -287,6 +287,11 @@ if args.origin == "us":
             serial += 1
 imb.write_current_serial(serial)
 
+def serialize_paths(obj: object):
+    if isinstance(obj, Path):
+        return str(obj)
+    raise TypeError("Type not Serializable")
+
 with (root_dir() / "options.json").open("w") as options:
     json.dump(
         fp=options,
@@ -294,6 +299,7 @@ with (root_dir() / "options.json").open("w") as options:
             "args": args.__dict__,
             "cards": cards,
         },
+        default=serialize_paths
     )
 
 if args.dont_compile: