cache_dir params not working?

[cyrinux]

Hi, Thx for this good program, under archlinux i got with python3

❯ bum --cache_dir=/home/cyril/.covers/
Traceback (most recent call last):
  File "/usr/bin/bum", line 11, in <module>
    load_entry_point('bum==0.1.3', 'console_scripts', 'bum')()
  File "/usr/lib/python3.7/site-packages/bum/__main__.py", line 69, in main
    song.get_art(args.cache_dir, args.size, client)
  File "/usr/lib/python3.7/site-packages/bum/song.py", line 34, in get_art
    file_name = cache_dir / file_name
TypeError: unsupported operand type(s) for /: 'str' and 'str'

[lasers]

The problem is probably because default cache_dir is Pathlib.Path.home() / ".cache/bum" --> ~/.cache/bum. If we specifiy cache_dir, it gets a string so we get your exception above. We need to convert user-defined cache_dir string to Pathlib.Path too.

Untested.

diff --git a/bum/__main__.py b/bum/__main__.py
index 76c6868..3c9ac84 100644
--- a/bum/__main__.py
+++ b/bum/__main__.py
@@ -26,9 +26,13 @@ def get_args():
                      help="what size to display the album art in.",
                      default=250)
 
+    def fix_cache_dir(cache_dir):
+        return pathlib.Path(cache_dir)
+
     arg.add_argument("--cache_dir", metavar="\"/path/to/dir\"",
                      help="Where to store the downloaded cover art.",
-                     default=pathlib.Path.home() / ".cache/bum")
+                     default=pathlib.Path.home() / ".cache/bum",
+                     type=fix_cache_dir)
 
     arg.add_argument("--version", action="store_true",
                      help="Print \"bum\" version.")