A pattern for testing anonymous functions and asserting expected behaviour through nested calls using JasmineBDD.

Anonymous Function Testing.js

// Notes: This is a way @Searls and I came up with that lets you
//        test deeply nested anonymous functions and callbacks.

// We don't recommend nesting things this deep but we _do_ like the closure scoping in the tests. 
// Any suggestions or improvements would be welcome :)

// The Codez, A little modal window framework
(function($, _) {

	$.cil = $.cil || {};
	$.cil.modals = {};

	var m = $.cil.modals;

	m.MODAL_LINK_TEMPLATE =
	'<a href="<%= url %>" class="modal" data-controller="<%= controller %>" title="<%= title %>">' +
		'<%= label %>' +
	'</a>';

	m.MODAL_TEMPLATE = '<div class="modal cil-template"></div>';

	m.bind = function() {
		$("body").delegate("a.modal", "click", m.open);
	};

	m.link = function(context) {
		return _.template(m.MODAL_LINK_TEMPLATE, context);
	};

	m.hide = function() {
		$("div.modal").dialog("close");
		$('div.modal').remove();
	};

	m.open = function(e) {
		var $modal = $(m.MODAL_TEMPLATE);
		var $link = $(this);
		var controller = m._extractController($link);

		$modal.appendTo("body"); // level 1 specs test from here

		$.cil.loadingIndicator.show();

		$modal.load($link.attr("href"), function() { // level 2 specs test from here
			$.cil.loadingIndicator.hide();
			$modal.dialog({
				modal: true,
				minWidth: 450,
				title: controller.title,
				buttons: controller.buttons,
				open: function(ev, ui) {
					controller.onLoaded({ // level 3 specs test from here
						link: $link,
						container: $modal
					});
				}
			});
		});

		e.preventDefault();
	};

	m._extractController = function($link) {
		var ns = $link.attr("data-controller").split(".");
		return $.cil[ns[0]][ns[1]];
	};

	$.subscribe('/cil/modals/action-complete', m.hide);

})(jQuery, _);

// The Tests
describe('Modal Window Generator', function() {
	
	var sut = $.cil.modals,
		support = $.jasmine, // requires https://github.com/searls/jasmine-fixture
		$link,
		linkMetaData;
		
	beforeEach(function() {
		// setup fixtures
		linkMetaData = {
			url: '/test/url',
			controller: 'test.controller',
			title: 'Test Link!',
			label: 'Test Link Text'
		};
		$link = $(sut.link(linkMetaData));
	});
	
	// Level 1
	describe('#open', function() {
		var url, loadedCallback;
		
		beforeEach(function() {
			spyOn($.fn, 'load').andCallFake(function('/some/url', callback) {
				loadedCallback = callback;
			});
			sut.open.call($link, { preventDefault: function() {} });
		});
		
		// Level 1 Assertions
		it('loads remote content into the modal', function() {
			expect($.fn.load).toHaveBeenCalledWith(linkMetaData.url, loadedCallback);
		});
		
		// ... *snip*
				
		// Level 2
		describe('$.load anonymous handler', function() {
			var dialogParams;
			
			beforeEach(function() {
				spyOn($.fn, 'dialog').andCallFake(function(options) {
					dialogParams = options;
				});
				// execute the callback passed in from our previous execution scope
				loadedCallback();
			});
			
			// Level 2 Assertions
			it('sets the modal flag to true', function() {
				expect(dialogParams.modal).toBe(true);
			});	   
			
			// ... *snip*
			
			// Level 3, feeling like inception all of a sudden...
			describe('controller.onLoaded arguments', function() {
				var onLoadedParams;
				
				beforeEach(function() {
					$.cil.test.controller.onLoaded = function() {};
					spyOn($.cil.test.controller, 'onLoaded').andCallFake(function(options) {
						onLoadedParams = options;
					});
					dialogParams.open();
				});
				
				it('passes the link', function() {
					expect(onLoadedParams.link).toBe('a.modal');
				});
				
				it('passes the modal as container', function() {
					expect(onLoadedParams.container).toBe('div.modal');
				});
			});
		});		   
	});
});