How to test if an event handler is set in a Marionette.js view?

Question

There is a Marionette.js view which acts as a login form. The following code sample shows the relevant code parts including an error I already fixed:

MyApp.module("User", function(User, App, Backbone, Marionette, $, _) {

  User.LoginView = Marionette.ItemView.extend({

    className: "reveal-modal",
    template: "user/login",

    ui: {
      signInForm: "#signin-form"
    },

    events: {
      "submit #signin-form": "onSignInFormSubmit"
    },

    onRender: function() {
      var self = this;
      var $el = this.$el;

      // [...] Render schema

      _.defer(function(){
        $el.reveal({
          closeOnBackgroundClick: false,
          closed: function(){
            self.close(); // <-- This is incorrect. Do not close the ItemView directly!
          }
        });
      });
    },

    onSignInFormSubmit: function(event) {
      event.preventDefault();
      var errors = this.signInForm.validate();
      var data = this.signInForm.getValue();
      // [...] Notify that data has been submitted.    
    },

    hideForm: function() {
      this.$el.trigger("reveal:close");
    }

  });
});

I noticed a major mistake in my implementation. In the callback function closed of Reveal I decided to close the ItemView directly which is wrong as you can read in the documentation of Marionette.js:

View implements a close method, which is called by the region managers automatically.

Bugfix: Instead close() should be called on the region. I fixed this error.

---

Now I ask myself how can I actually write a test which covers the problem. I use Jasmine for testing. I noticed that the event handler onSignInFormSubmit is no longer called after I have incorrectly closed the ItemView and try to re-submit the form.

Here is a first draft of the test which unfortunately does fail also with the bugfix:

it("should call the submit handler for the sign-in form", function() {
  spyOn(userController.loginView, "onSignInFormSubmit");
  spyOn(userController.loginView.signInForm, "validate").andCallFake(function(params) {
    return null;
  });
  userController.loginView.hideForm();
  userController.loginView.ui.signInForm.trigger("submit");
  expect(userController.loginView.onSignInFormSubmit).toHaveBeenCalled();
});

Maybe one could also test if the event handler is registered such as:

expect(userController.loginView.events["submit #signin-form"]).toEqual("onSignInFormSubmit");