Fixes TypeError in the Discogs plugin

[amogus07]

Description

Fixes the following error:

Traceback (most recent call last):
  File "/home/konstantink/.local/bin/beet", line 8, in <module>
    sys.exit(main())
             ^^^^^^
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/ui/__init__.py", line 1865, in main
    _raw_main(args)
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/ui/__init__.py", line 1852, in _raw_main
    subcommand.func(lib, suboptions, subargs)
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/ui/commands.py", line 1395, in import_func
    import_files(lib, paths, query)
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/ui/commands.py", line 1326, in import_files
    session.run()
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/importer.py", line 360, in run
    pl.run_parallel(QUEUE_SIZE)
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/util/pipeline.py", line 447, in run_parallel
    raise exc_info[1].with_traceback(exc_info[2])
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/util/pipeline.py", line 312, in run
    out = self.coro.send(msg)
          ^^^^^^^^^^^^^^^^^^^
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/util/pipeline.py", line 195, in coro
    func(*(args + (task,)))
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/importer.py", line 1497, in lookup_candidates
    task.lookup_candidates()
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/importer.py", line 688, in lookup_candidates
    artist, album, prop = autotag.tag_album(
                          ^^^^^^^^^^^^^^^^^^
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/autotag/match.py", line 548, in tag_album
    for matched_candidate in hooks.album_candidates(
                             ^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/plugins.py", line 593, in decorated
    for v in generator(*args, **kwargs):
             ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/autotag/hooks.py", line 759, in album_candidates
    yield from plugins.candidates(items, artist, album, va_likely, extra_tags)
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beets/plugins.py", line 390, in candidates
    yield from plugin.candidates(
               ^^^^^^^^^^^^^^^^^^
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beetsplug/discogs.py", line 188, in candidates
    return self.get_albums(query)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beetsplug/discogs.py", line 335, in get_albums
    return [
           ^
  File "/home/konstantink/.local/share/pipx/venvs/beets/lib64/python3.12/site-packages/beetsplug/discogs.py", line 419, in get_album_info
    ", ".join(result.data["formats"][0].get("descriptions", []))
TypeError: can only join an iterable

IDK what exactly caused it, but this seems to have fixed it without causing additional problems.

To Do

• Documentation.
• Changelog.
• Tests.

[github-actions]

Thank you for the PR! The changelog has not been updated, so here is a friendly reminder to check if you need to add an entry.

[snejus]

I tested it with a release that has a couple of formats and I think we'd want to re-think the solution. Could you by any chance share the URL of the release that caused the issue?

[snejus]

I tested it with a release that has a couple of formats and I think we'd want to re-think the solution. Could you by any chance share the URL of the release that caused the issue?

@amogus07 can you please share the URL of the release that caused the failure you reported above, for testing?

[amogus07]

I tested it with a release that has a couple of formats and I think we'd want to re-think the solution. Could you by any chance share the URL of the release that caused the issue?

@amogus07 can you please share the URL of the release that caused the failure you reported above, for testing?

I don't have it, unfortunately

[mwean]

I'm getting this error too. Here is one example. The result formats data is [{'name': 'CD', 'qty': '1', 'descriptions': None}].

[amogus07]

I'm getting this error too. Here is one example. The result formats data is [{'name': 'CD', 'qty': '1', 'descriptions': None}].

oh, so the problem occurs when description is empty?

[snejus]

I'm getting this error too. Here is one example. The result formats data is [{'name': 'CD', 'qty': '1', 'descriptions': None}].

Here we go, that's amazing, thanks @mwean! I sensed that the description may have been None in this case.

[amogus07]

now, someone needs to add a test case (idk how to do that) and this should be good to get merged, right?

[snejus]

now, someone needs to add a test case (idk how to do that) and this should be good to get merged, right?

Indeed. I can help you with the test :)

[snejus]

@amogus07 have just isolated this change into a separate method and added a test