Karma: Error: [$injector:nomod] Module 'app' is not available - angularjs

Question

I am new to Angular World and very beginner at Karma.
I am receiving the following error when I am trying to run the Karma-Jasmine Unit test.
{
"message": "An error was thrown in afterAll\nUncaught Error: [$injector:nomod] Module 'app' is not available! You either misspelled the module name or forgot to load it. If registering a module ensure that you specify the dependencies as the second argument.\nhttp://errors.angularjs.org/1.6.9/$injector/nomod?p0=app", "str": "An error was thrown in afterAll\nUncaught Error: [$injector:nomod] Module 'app' is not available! You either misspelled the module name or forgot to load it. If registering a module ensure that you specify the dependencies as the second argument.\nhttp://errors.angularjs.org/1.6.9/$injector/nomod?p0=app"
}
Going through various posts, I found that this error occurs when:
Misspelled the module name
Forget to register the module
Forget to load dependencies
But it seems that none of the above issue applies to my app. My App is very small as of now. I am posting my almost whole app for reference.
Please find my code below for reference.
app.module.js
(function () {
"use strict";
angular
.module("app", [
"ngRoute",
"ngMessages",
"ngclipboard",
"ui.router"
])
.config(configurations);
function configurations($locationProvider, $routeProvider, $httpProvider) {
$locationProvider.hashPrefix("!");
$routeProvider
.when("/licensing", {
templateUrl: "app/licensing/licensing.html",
controller: "LicensingController",
controllerAs: "vm"
})
.otherwise({
redirectTo: "/licensing"
});
}
})();
index.html
<!-- Angular Libraries -->
<script src="./node_modules/angular/angular.js"></script>
<script src="./node_modules/angular-route/angular-route.js"></script>
<script src="./node_modules/angular-messages/angular-messages.js"></script>
<script src="./node_modules/#uirouter/angularjs/release/angular-ui-router.js"></script>
<script src="./scripts/clipboard.js"></script>
<script src="./libs/angular/angular-clipboard.js"></script>
<script src="./app/app.module.js"></script>
<!-- Controllers -->
<script src="./app/authentication/login.controller.js"></script>
<script src="./app/authentication/forgetpassword.controller.js"></script>
<script src="./app/licensing/licensing.controller.js"></script>
karma.conf.js
// base path that will be used to resolve all patterns (eg. files, exclude)
basePath: '',
// list of files / patterns to load in the browser
files: [
'./node_modules/angular/angular.js', // Angular Framework
'./node_modules/#uirouter/angularjs/release/angular-ui-router.js', // UI-Router
'./node_modules/angular-mocks/angular-mocks.js', // Loads the Module for Tests
'./app/licensing/licensing.controller.js', // Licensing Controller
'./app/app.module.js', // Our Angular App
'./app/licensing/licensing.controller.spec.js' // Licensing Controller Spec File
],
license.controller.js
(function () {
"use strict";
angular
.module("app")
.controller("LicensingController", LicensingController)
function LicensingController() {
// Some code
}
})();
licensing.controller.spec.js
describe("Licensing Form", function () {
var LicensingController;
beforeEach(angular.mock.module("app"));
beforeEach(inject(function (_LicensingController_) {
LicensingController = _LicensingController_;
}));
it("This is a Dummy Test for (2 + 2)", function () {
expect(2 + 2).toEqual(4);
});
});