music_library/backlog/tasks/ml-153 - Move-MusicBrainz-data-transformations-out-of-Record-schema.md

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

id	title	status	assignee	created_date	updated_date	labels	dependencies	references	priority
ML-153	Move MusicBrainz data transformations out of Record schema	Done		2026-04-30 10:48	2026-04-30 12:20	refactor records musicbrainz		lib/music_library/records/record.ex lib/music_brainz/release_group.ex	medium

Description

The Record schema (lib/music_library/records/record.ex) contains MusicBrainz-specific data transformation functions that belong in the MusicBrainz API layer, not in the database schema:

• parse_artists/1 — extracts artist credits from MusicBrainz API response
• parse_subtype/2 / parse_secondary_types/1 — maps MusicBrainz type strings to Record enum values
• attrs_from_release_group/1 — builds a changeset attrs map from a MusicBrainz release group

These functions are called by add_musicbrainz_data/2 (changeset pipeline) and during MusicBrainz import flows.

Move the parsing functions to appropriate MusicBrainz modules (e.g., MusicBrainz.ReleaseGroup already has related helpers) and keep only struct introspection/presentation functions on Record (artist_names/1, releases/1, released?/1, format_release_date/1, etc.).

Update callers in:

• Record.changeset/2 and add_musicbrainz_data/2
• Records context (import functions)
• Any tests that reference the moved functions directly

Acceptance Criteria

• #1 parse_artists/1, parse_subtype/2, parse_secondary_types/1, and attrs_from_release_group/1 are moved to MusicBrainz modules
• #2 Record schema retains only struct introspection and presentation helpers
• #3 All callers are updated to use the new locations
• #4 Full test suite passes
• #5 @moduledoc on moved functions explains their purpose

Implementation Notes

parse_artist_credits/1 and parse_record_type/2 moved to MusicBrainz.ReleaseGroup — these are pure MusicBrainz data parsing functions with no Record schema knowledge. attrs_from_release_group/1 stays on Record because it maps MusicBrainz response fields to Record changeset keys (an implicit Record schema dependency). The Record schema now delegates parsing to ReleaseGroup.parse_artist_credits/1 and ReleaseGroup.parse_record_type/2, keeping the coupling boundary clean: MusicBrainz modules parse MusicBrainz data; the Record schema owns its own field mapping.

Final Summary

Moved parse_artist_credits/1 and parse_record_type/2 to MusicBrainz.ReleaseGroup. attrs_from_release_group/1 kept on Record to avoid reverse dependency — it now delegates parsing to the new MusicBrainz functions. Record.update_artists/1 uses ReleaseGroup.parse_artist_credits/1. All 884 tests pass.