Add validation.

comfy/cli_args.py

@@ -47,7 +47,6 @@ def __call__(self, parser, namespace, values, option_string=None):
 parser.add_argument("--output-directory", type=str, default=None, help="Set the ComfyUI output directory.")
 parser.add_argument("--temp-directory", type=str, default=None, help="Set the ComfyUI temp directory (default is in the ComfyUI directory).")
 parser.add_argument("--input-directory", type=str, default=None, help="Set the ComfyUI input directory.")
-parser.add_argument("--user-directory", type=str, default=None, help="Set the ComfyUI user directory.")
 parser.add_argument("--auto-launch", action="store_true", help="Automatically launch ComfyUI in the default browser.")
 parser.add_argument("--disable-auto-launch", action="store_true", help="Disable auto launching the browser.")
 parser.add_argument("--cuda-device", type=int, default=None, metavar="DEVICE_ID", help="Set the id of the cuda device this instance will use.")
@@ -172,6 +171,8 @@ def is_valid_directory(path: Optional[str]) -> Optional[str]:
     help="The local filesystem path to the directory where the frontend is located. Overrides --front-end-version.",
 )
 
+parser.add_argument("--user-directory", type=is_valid_directory, default=None, help="Set the ComfyUI user directory with an absolute path.")
+
 if comfy.options.args_parsing:
     args = parser.parse_args()
 else: