mbsync does not yield albuminfo_received / trackinfo_received as the docs suggest

[iliana]

Problem

I am writing a plugin to override metadata and wish for it to apply when using beet mbsync. The documentation for plugin events implies that listening for albuminfo_received and trackinfo_received will allow me to do just that.

However, running beet -vv mbsync for a given query does not show a log message saying that the event was ever sent.

$ beet -vv mbsync 'album:autobahn'
user configuration: /home/ilianaw/.config/beets/config.yaml
data directory: /home/ilianaw/.config/beets
plugin paths: /home/ilianaw/.config/beets/plug
Sending event: pluginload
/usr/lib/python3.6/site-packages/beets/plugins.py:114: DeprecationWarning: inspect.getargspec() is deprecated, use inspect.signature() or inspect.getfullargspec()
  argspec = inspect.getargspec(func)
library database: /home/ilianaw/.config/beets/library.db
library directory: /srv/media/ilianaw_music
Sending event: library_opened
Requesting MusicBrainz release f8fab745-79bd-31cd-be4b-ceb3d7e1e799
primary MB release type: album
mbsync: applying changes to Kraftwerk - Autobahn
Sending event: cli_exit

It appears (although I've not tested it) that this is a regression that occurred in 18a14e8. mbsync uses hooks.album_for_mbid, but only hooks.albums_for_id yields an albuminfo_received.

The solution that comes to my mind is to partially revert this commit by removing the @plugins.notify_info_yielded decorator on albums_for_id/tracks_for_id and using plugins.send. The use of @plugins.notify_info_yielded on album_candidates/item_candidates seems fine at first glance. If this sounds correct, I'll be happy to send a pull request.

Setup

• OS: Fedora 28
• Python version: 3.6.5
• beets version: 1.4.6
• Turning off plugins made problem go away (yes/no): no

My configuration (output of beet config) is:

plugins: chroma fetchart embedart mbsync scrub override
pluginpath: ~/.config/beets/plug
directory: /srv/media/ilianaw_music
ui:
  color: yes
paths:
  default: "$albumartist/$album%aunique{}/$track $title"
  singleton: "$artist/$title"
  comp: "Various Artists/$album%aunique{}/$track $title"
fetchart:
  sources:
    - amazon
    - coverart
  store_source: yes
embedart:
  remove_art_file: yes

(override is the plugin I am attempting to write.)

[sampsyo]

Thanks for your detective-work on this! I agree entirely with your astute diagnosis.

I've been trying to think of a way to salvage the decorator style, which is nice in itself, but I've been unable to come up with a better solution. So yes, I also concur with your idea to remove those decorators and replace them with explicit send calls---that seems like the most straightforward way to get both ID-based lookup functions to emit the right events.

Thank you again!