music_library/backlog/completed/ml-63 - Break-bidirectional-dependency-between-Records-and-Artists.md

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

id	title	status	assignee	created_date	labels	dependencies	references	priority
ML-63	Break bidirectional dependency between Records and Artists	Done		2026-04-20 08:54			https://github.com/cloud8421/music_library/issues/112	medium

Description

GitHub: created 2026-03-12 · updated 2026-03-12 · closed 2026-03-12

Problem

Records and Artists have a bidirectional dependency: Records → Artists (async Oban calls on create/delete) and Artists → Records (get_collected_artist_ids/0 joins Records.Record directly). The direct schema query from Artists → Records is a hard compile-time dependency on another context's schema.

Proposed solution

Move get_collected_artist_ids/0 into Collection (which already owns the purchased_at IS NOT NULL scoping concern). Then Artists.get_similar_artists/1 calls Collection.collected_artist_ids() instead. Accept ArtistRecord as a shared read-only schema used by both domains.

Steps

1. Add collected_artist_ids/0 to MusicLibrary.Collection
2. Update Artists.get_similar_artists/1 to call Collection.collected_artist_ids()
3. Remove Records.Record alias from Artists
4. Remove the private get_collected_artist_ids/0 from Artists
5. Update tests

Files involved

• lib/music_library/artists.ex
• lib/music_library/collection.ex
• Tests for Artists and Collection