module.exports = models => { const { ShelfItem, Shelf, BookReference, Status, } = models; ShelfItem.belongsTo(Shelf, { foreignKey: 'shelfId', onDelete: 'CASCADE', }); ShelfItem.belongsTo(BookReference, { foreignKey: 'bookId', onDelete: 'CASCADE', }); ShelfItem.hasMany(Status); return ShelfItem; }