halting events in bookshelf

model.js

module.exports = Bookshelf.Model.extend({
  initialize: function () {
    this.on('saving', this.validate);
  },
  validate: function () {}
});

test.js

describe('Model events', function () {
  var model;
  beforeEach(function () {
    model = new Model();
  });

  it('should permit saving by default', function () {
    return model.save();
  });

  it('halts saving if validation throws', function () {
    var err = new Error();
    sinon.stub(model.validate).throws(err);
    return expect(model.save())
      .to.be.rejectedWith(err);
  });

  it('halts saving if the validation returns a rejected promise', function () {
    var err = new Error();
    sinon.stub(model.validate).returns(Promise.reject(err));
    return expect(model.save())
      .to.be.rejectedWith(err);
  });
  
});