The playlist components (https://github.com/metabrainz/listenbrainz-server/tree/master/frontend/js/src/playlists) were created during a hackweek and lack any form of tests.

At least the Playlists, Playlist and PlaylistItemCard components (the two main pages) should have solid tests emulating user actions (edit playlist, add/move/delete track, create/delete playlist, user allowed or not to edit, etc. ) and ensuring the state was changed accordingly and the API calls are what we expect.

The utils can get simple unit tests and should test robustness by throwing the util functions various inputs