AngularJs 1.X custom directive in separated file is not working

Question

Hi I'm trying to separate the code of a custom directive to manage checkboxes to a different file, but is not working and also it seems that is not loading when I debug with devtools I'm not able to see this new file.

not.js

(function () {
    'use strict';

    var sn = angular.module('notApp');
    sn.controller('notController', ['$scope', '$window', '$timeout', 'dataContext', notController]);

    function notController($scope, $window, $timeout, dataContext) {
    }

    sn.directive('checkList', function () {
        return {

        };
    });

})();

notApp.js

(function () {
    'use strict';
    angular.module('templates-notHtml', []); 
    angular.module('notApp', [
        'templates-notHtml'
    ]);
})();

notDataContext.js

(function () {
    'use strict';

    var sn = angular.module('notApp');

    var dataContext = sn.service('dataContext', ['$http', '$window', '$rootScope', dataContextFunction]);

    function dataContextFunction($http, $window, $rootScope) {

        this.getPeriods = function () {
            return $http({
                method: 'GET',
                url: '..........'
            }).then(function (success) {
                return success;
            });
        };
    }
})();

not.html

<div ng-app="notApp">
    <div id="sn" data-ng-controller="notController" class="mainDiv">
    </div>
</div>

<script src="not.js"></script>

In this way the directive is working fine but when I separate the directive to another file, for example to customDirectives.js:

customDirectives.js

var sn = angular.module('notApp');

sn.directive('checkList', function () {
    return {}
};
});

and then adding the script reference of customDirectives.js in not.html like:

not.html

<div ng-app="notApp">
    <div id="sn" data-ng-controller="notController" class="mainDiv">
    </div>
</div>

<script src="not.js"></script>
<script src="customDirectives.js"></script>

Stops working by this way, and also I'm not able to see customDirectives.js loaded in Chrome.

Any idea on what I'm doing wrong?