music_library/backlog/tasks/ml-10 - Break-Records-→-Artists-→-Collection-→-Records-static-alias-cycle.md

id, title, status, assignee, created_date, labels, dependencies, references, priority

id	title	status	assignee	created_date	labels	dependencies	references	priority
ML-10	Break Records → Artists → Collection → Records static alias cycle	To Do		2026-04-20 08:49			https://github.com/cloud8421/music_library/issues/173	low

Description

GitHub: created 2026-04-16 · updated 2026-04-16

Summary

A three-way compile-time alias cycle exists between the three context facades. mix xref graph --format cycles surfaces it. No runtime cycle (the Records → Artists edge is Oban-async).

Evidence

Records → Artists:  lib/music_library/records.ex:10 (alias)
  Artists.refresh_artist_info_async/1   records.ex:385
  Artists.prune_artist_info_async/1     records.ex:415

Artists → Collection: lib/music_library/artists.ex:10 (alias)
  Collection.collected_artist_ids/0     artists.ex:29 (used inside get_similar_artists/1)

Collection → Records: lib/music_library/collection.ex:9 (alias)
  Records.search_records/4, Records.search_records_count/2, Records.essential_fields/0

Relation to #112

#112 fixed the earlier Records ↔ Artists bidirectional dependency by moving collected_artist_ids/0 from Artists to Collection. That fix made the shape Records → Artists → Collection → Records — unidirectional in hops, but still a compile-time cycle.

Fix

Parametrize Artists.get_similar_artists/1 to receive collected_artist_ids instead of fetching inline:

# in Artists
def get_similar_artists(artist, collected_artist_ids) do
  # ... use the set passed in
end

# in the caller (ArtistLive.Show)
collected = Collection.collected_artist_ids()
similar = Artists.get_similar_artists(artist, collected)

This removes the Artists → Collection edge without moving any behaviour, and the "which are in the collection?" filtering becomes a caller concern.

Acceptance Criteria

• mix xref graph --format cycles reports no cycles involving these three modules
• ArtistLive.Show tests still pass

• #1 mix xref graph --format cycles reports no cycles involving these three modules
• #2 ArtistLive.Show tests still pass