[rianjs]

Summary

• share generic table and ID render loops across track, album, artist, saved-item, and playlist output
• share generic field selection and field-name formatting across track, album, artist, and playlist output
• remove saved-only cases from base cell renderers and temporary saved-item ID slices

LOC delta: +114/-322 (net -208)

Playlist scope

• playlist tables, playlist IDs, and playlist field selection use the shared helpers
• playlist-item rendering remains separate because cells depend on row offset/position, and its ID output intentionally skips missing IDs

Verification

• go build ./...
• go vet ./...
• make test
• golangci-lint run

Closes #32

[rianjs]

TDD assessment

Verdict: insufficient.

The observable rendering paths are otherwise well pinned:

• Table shape is covered for track, album, artist, and playlist with exact byte strings, including headers, | delimiters, trailing newlines, and header-only empty pages. The album/artist empty cases are exercised through search command tests; track and playlist also have direct output tests.
• Saved-track and saved-album tests pin both the ADDED_AT header and a rendered timestamp value.
• Removing the TrackAddedAt and AlbumAddedAt cases from trackCell/albumCell is observationally neutral: each deleted case returned -, exactly as the unchanged default branch does. Saved values still route through savedTrackCell/savedAlbumCell and are covered.
• Saved IDs are pinned: the track library --id test exercises RenderSavedTrackIDs; saved albums are covered both directly and through library --id. The allocation removal therefore has output coverage.

The gap is the four family-specific unknown-field messages. Existing tests only use strings.Contains on the valid fields: suffix, so all would pass if the shared helper supplied the wrong noun. In particular, playlist does not pin unknown playlist field.

Cheapest fix: strengthen the existing assertions in internal/output/track_test.go (TestTrackProjectionRejectsUnknownAndIDsHaveNoHeader), internal/output/catalog_test.go (TestRenderAlbumsShapes and TestRenderArtistsShapes), and internal/output/playlist_test.go (TestPlaylistFieldsAndRendering) to compare the full errors:

• unknown track field "nope"; valid fields: ID, TRACK, ARTIST_IDS, ARTISTS, ALBUM_ID, ALBUM, DURATION, URI, URL, DISC_NUMBER, TRACK_NUMBER, EXPLICIT, RESTRICTION, ARTWORK
• unknown album field "nope"; valid fields: ID, ALBUM, ARTIST_IDS, ARTISTS, RELEASE_DATE, TOTAL_TRACKS, URI, URL, ALBUM_TYPE, RELEASE_DATE_PRECISION, RESTRICTION, ARTWORK
• unknown artist field "nope"; valid fields: ID, ARTIST, URI, URL, ARTWORK
• unknown playlist field "nope"; valid fields: ID, PLAYLIST, OWNER_ID, OWNER, ITEM_COUNT, PUBLIC, COLLABORATIVE, URI, URL, SNAPSHOT_ID, DESCRIPTION, ARTWORK

No new test functions or helper-level tests are needed. Current suite passes: 472 tests across 22 packages.