spellsaurus/api/models/permission-model.js

const bookshelf = require('../database/bookshelf').bookshelf

require('./role-model')

let Permission = bookshelf.Model.extend({
    tableName: 'permission',
    hidden: ['id'],
    role() {
        return this.belongsToMany('Role', 'role_permission')
    }
})

module.exports = bookshelf.model('Permission', Permission);