A way to spy on and verify the selector when using this.$(selector) with a Backbone.View

prod.js

// The production code in question, part of a backbone view

showSearch: function () {
  this.$('.dataTables_filter').show();
}

spec.js

// We have a view with a function that binds an event to a button that shows a search box

describe('showSearch', function () {
  var showSpy;
  
  beforeEach(function () {
    showSpy = jasmine.createSpy('showSpy');
    spyOn(view, '$').andReturn({ show: showSpy });
    view.showSearch();
  });

  it('should trigger show on its search filters', function () {
    expect(view.$).toHaveBeenCalledWith('.dataTables_filter');
    expect(showSpy).toHaveBeenCalled();
  });
});