Most rules files have very specific requirements for the playlist that should accompany them. Playlists in another format will run into errors. Ideally, early on, though not infrequently the errors occur midway and (due to randomized order) in a hard to reproduce pattern.

We should add validation to each rules file (see for an example congosamediff) which makes the (now implicit) assumptions explicit.

Ideally, we would display such validation errors in the admin interface: i.e., a user creates an experiment with a given rules file, and then, when they tie a specific playlist to it, the admin interface issues warnings about incompatibility of the playlist and rules.

Technical implementation

• Update rule base class with an (empty) validations array property
• Update rule base class with a validate function
• Add validation endpoint that uses the validation rules of an experiment's rules for its playlist
• Use validation endpoint in experiment form and show warnings & errors in the admin interface