lastgenre: Fix fetching artist genre for multi-artist albums

[JOJ0]

Often last.fm does not have artist genres for delimiter-separated artist names (eg. "Artist One, Artist Two"). This splits out by (the configured) delimiter and gathers each artist's last.fm genre.

FIXME: It would be cool if a configured list of artist name separators would be used instead of a hard-coded one.

Description

Fixes #X.

To Do

• Documentation.
• Changelog.
• Tests.

Summary by Sourcery

Enhance album genre lookup to handle multi-artist album artists by splitting the albumartist string on configured and common separators, then aggregating each sub-artist’s genres from Last.fm.

New Features:

• Split multi-artist albumartist strings on a configurable delimiter and common separators to fetch each artist’s genre.
• Introduce fetch_split_album_artist_genre helper method to query Last.fm per split artist.

Enhancements:

• Define a regex pattern of common separators (e.g., feat., &, x, +, and others) for detecting and splitting multi-artist names.

[sourcery-ai]

Reviewer's Guide

Introduces splitting logic for multi-artist album names: a new helper method fetch_split_album_artist_genre wraps the existing API lookup, and _try_resolve_stage is extended to detect configured separators, split the albumartist string, and aggregate each artist’s genre.

Sequence diagram for multi-artist album genre fetching

sequenceDiagram
    participant Plugin as LastGenrePlugin
    participant Album as Album
    participant LastFM as LASTFM
    Plugin->>Album: Get albumartist
    Plugin->>Plugin: Check for separators in albumartist
    alt Separators found
        Plugin->>Plugin: Split albumartist into individual artists
        loop For each split artist
            Plugin->>LastFM: get_artist(split_artist)
            LastFM-->>Plugin: Return genre
            Plugin->>Plugin: Aggregate genre
        end
    else No separators found
        Plugin->>LastFM: get_artist(albumartist)
        LastFM-->>Plugin: Return genre
    end
    Plugin->>Album: Assign aggregated genre(s)

Loading

Class diagram for updated LastGenrePlugin methods

classDiagram
    class LastGenrePlugin {
        +fetch_album_artist_genre(obj)
        +fetch_split_album_artist_genre(split_artist)
        +fetch_artist_genre(item)
        +_try_resolve_stage(stage_label, keep_genres, new_genres)
    }
    LastGenrePlugin : fetch_split_album_artist_genre(split_artist)
    LastGenrePlugin : _try_resolve_stage(stage_label, keep_genres, new_genres)
    LastGenrePlugin : fetch_album_artist_genre(obj)
    LastGenrePlugin : fetch_artist_genre(item)
    LastGenrePlugin --> LASTFM : get_artist(artist_name)

Loading

File-Level Changes

Change	Details	Files
Add fetch_split_album_artist_genre helper for single-artist lookups	Define fetch_split_album_artist_genre method with docstring Use existing _last_lookup API call to fetch genre for a given artist name	beetsplug/lastgenre/__init__.py
Enhance _try_resolve_stage to handle multi-artist album names	Log a debug message when no album artist genre is found Define a list of regex-escaped separators (configurable delimiter plus common connectors) Detect presence of any separator in the albumartist string and log splitting event Build a combined regex pattern and split the albumartist string on all separators Iterate over each trimmed artist segment, fetch its genre with the new helper, and append to new_genres	beetsplug/lastgenre/__init__.py

---

Tips and commands

Interacting with Sourcery

• Trigger a new review: Comment @sourcery-ai review on the pull request.
• Continue discussions: Reply directly to Sourcery's review comments.
• Generate a GitHub issue from a review comment: Ask Sourcery to create an
  issue from a review comment by replying to it. You can also reply to a
  review comment with @sourcery-ai issue to create an issue from it.
• Generate a pull request title: Write @sourcery-ai anywhere in the pull
  request title to generate a title at any time. You can also comment
  @sourcery-ai title on the pull request to (re-)generate the title at any time.
• Generate a pull request summary: Write @sourcery-ai summary anywhere in
  the pull request body to generate a PR summary at any time exactly where you
  want it. You can also comment @sourcery-ai summary on the pull request to
  (re-)generate the summary at any time.
• Generate reviewer's guide: Comment @sourcery-ai guide on the pull
  request to (re-)generate the reviewer's guide at any time.
• Resolve all Sourcery comments: Comment @sourcery-ai resolve on the
  pull request to resolve all Sourcery comments. Useful if you've already
  addressed all the comments and don't want to see them anymore.
• Dismiss all Sourcery reviews: Comment @sourcery-ai dismiss on the pull
  request to dismiss all existing Sourcery reviews. Especially useful if you
  want to start fresh with a new review - don't forget to comment
  @sourcery-ai review to trigger a new review!

Customizing Your Experience

Access your dashboard to:

• Enable or disable review features such as the Sourcery-generated pull request
  summary, the reviewer's guide, and others.
• Change the review language.
• Add, remove or edit custom review instructions.
• Adjust other review settings.

Getting Help

• Contact our support team for questions or feedback.
• Visit our documentation for detailed guides and information.
• Keep in touch with the Sourcery team by following us on X/Twitter, LinkedIn or GitHub.

[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.

[codecov]

Codecov Report

❌ Patch coverage is 22.50000% with 31 lines in your changes missing coverage. Please review.
✅ Project coverage is 66.38%. Comparing base (55667fa) to head (314a914).
⚠️ Report is 28 commits behind head on master.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
beetsplug/lastgenre/__init__.py	22.50%	29 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5981      +/-   ##
==========================================
- Coverage   66.50%   66.38%   -0.13%     
==========================================
  Files         117      117              
  Lines       18123    18141      +18     
  Branches     3071     3081      +10     
==========================================
- Hits        12052    12042      -10     
- Misses       5415     5444      +29     
+ Partials      656      655       -1     

Files with missing lines	Coverage Δ
beetsplug/lastgenre/__init__.py	53.39% <22.50%> (-4.85%)	⬇️

... and 2 files with indirect coverage changes

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.