Testing in Angular.js

controller.js

angular.module('myMod', []).controller('MyCtrl', function($scope) {
	$scope.var = 'hello';
	$scope.thing = 'before';
	$scope.change = function(word) {
		$scope.var = word;
	};
	$scope.$watch('var', function() {
		$scope.thing = 'after';
	})
});

controller.spec.js

describe('controller', function() {

	beforeEach(module('myMod'));

	describe('MyCtrl', function() {
		var scope, createController;

		beforeEach(inject(function ($rootScope, $controller) {
			scope = $rootScope.$new();

			createController = function() {
				return $controller('MyCtrl', {
					'$scope': scope
				});
			};
		}));

		it('should initially have "hello" as the $scope.var value', inject(function() {
			var controller = createController();
			expect(scope.var).toEqual('hello');
		}));

		it('should change the $scope.var value', inject(function() {
			var controller = createController();
			scope.change('world');
			expect(scope.var).toEqual('world');
		}));

		it('should initially have "before" as the $scope.thing value', inject(function() {
			var controller = createController();
			expect(scope.thing).toEqual('before');
		}));

		it('should change the $scope.thing when $scope.var changes', inject(function() {
			var controller = createController();
			scope.change('world');
			scope.$digest();
			expect(scope.thing).toEqual('after');
		}));

	});

});

factory.js

angular.module('myMod').factory('wordsNotInAccountWords', function() {
	return function wordsNotInAccountWords(words, accountWords) {
		if (words && Array.isArray(accountWords)) {
			var wordsList = accountWords.map(function(word) {
				return word.name
			});
			return words.split(',').filter(function(word) {
				return wordsList.indexOf(word) < 0
			})
		} else {
			return []
		}
	}
});

factory.spec.js

describe('factory', function() {

	beforeEach(module('myMod'));

	describe('myMod.wordsNotInAccountWords', function() {

		it('should return an empty array if inputs are null', inject(function(wordssNotInAccountWords) {
			var result = wordsNotInAccountWords(null, null);
			expect(result).toEqual([])
		}));

		it('should return [] for an empty "words"', inject(function(wordsNotInAccountWords) {
			var words = ''
			var accountWords = [
				{ name: 'abc' },
				{ name: 'def' }
			]

			var result = wordsNotInAccountWords(words, accountWords);
			expect(result).toEqual([])
		}));

		it('should return the words that are not in accountWords', inject(function(wordsNotInAccountWords) {
			var words = 'abc,def'
			var accountWords = [
				{ name: 'def' },
				{ name: 'ghi' }
			]

			var result = wordsNotInAccountWords(words, accountWords);
			expect(result).toEqual(['abc'])
		}));

		it('should return all "words" when "accountWords" is empty', inject(function(wordsNotInAccountWords) {
			var words = 'abc,def'
			var accountWords = []

			var result = wordsNotInAccountWords(words, accountWords);
			expect(result).toEqual(['abc','def'])
		}));

	});

});