Add static file configuration to use the govuk npm directory and update related tests files

Author: Mouhajer-CO

Diff for: .env.example

@@ -4,7 +4,7 @@ AUTH_SIGN_OUT_URL=${AUTH_PATH}/?logout=true
 AWS_ACCESS_KEY_ID=DUMMYIDEXAMPLE
 AWS_SECRET_ACCESS_KEY=DUMMYEXAMPLEKEY
 BASE_URL=http://localhost:3000
-CDN_HOST=test
+CDN_HOST="d3ums2fp3imnyp.cloudfront.net"
 COOKIE_ID_NAME=github-requests
 COOKIE_PARSER_SECRET=test
 COOKIE_SESSION_SECRET=test

Diff for: README.md

@@ -79,15 +79,13 @@ The issue is then reviewed by the team, and further comments may be requested if
 
 ### Running local development environment with Docker
 
-Docker is used to run the application in **development** mode, with tooling setup to detect changes in local `src` directory and reload the container's node server. 
+Docker is used to run the application in **development** mode, with tooling setup to detect changes in local `src` directory and reload the container's node server.
 
 - Ensure that `NODE_ENV=development` is set in the `.env` file.
 
-- In order for static assets to be loaded, the `CDN_HOST` must be set to a CDN domain which serves the GOV.UK static assets.
-
 ### Building the application
 
-To build the project, run: 
+To build the project, run:
 
 ```sh
 make build

Diff for: src/app.ts

@@ -21,8 +21,11 @@ const app = express();
 
 app.disable('x-powered-by');
 
-const assetsPath = path.join(__dirname, '../assets');
-app.use('/assets', express.static(assetsPath));
+const govukPath = path.join(__dirname, '../node_modules/govuk-frontend/dist/govuk');
+
+app.use('/assets', express.static(`${govukPath}/assets`));
+app.use('/govuk-frontend.min.css', express.static(`${govukPath}/govuk-frontend.min.css`));
+app.use('/govuk-frontend.min.js', express.static(`${govukPath}/govuk-frontend.min.js`));
 
 app.use(express.json());
 app.use(express.urlencoded({ extended: false }));

Diff for: src/config/helmet.ts

@@ -1,31 +1,40 @@
 import express from 'express';
-import helmet from 'helmet';
+import helmet, { HelmetOptions } from 'helmet';
 
 import * as config from '../config';
 
-export const configureHelmet = (app: express.Application) => {
-    app.use(helmet({
-        referrerPolicy: {
-            policy: 'strict-origin-when-cross-origin'
+export const HELMET_OPTIONS: HelmetOptions = {
+    referrerPolicy: {
+        policy: 'strict-origin-when-cross-origin'
+    },
+    contentSecurityPolicy: {
+        useDefaults: true,
+        directives: {
+            defaultSrc: ["'self'"],
+            fontSrc: ["'self'", config.CDN_HOST],
+            styleSrc: [
+                "'self'",
+                "'unsafe-hashes'",
+                "'sha256-6FWIojjtZwiNizws7ImlHjGH3DA5yMh5x4c+/4UVpXk='",
+                config.CDN_HOST
+            ],
+            scriptSrc: [
+                "'self'",
+                "'sha256-pOe+O2hOZnTvxPXzgAfiocCoHgEZxBBgg+a66TylmHw='",
+                "'sha256-GUQ5ad8JK5KmEWmROf3LZd9ge94daqNvd8xy9YS1iDw='",
+                "'sha256-rDMP7u4Lf+tIufrYmUZIhcf2T3WBD4Pweu0EXe+qaLA='",
+                "'sha256-wJphCpPdstup3Ojta3HnXJ3EOilATTTWg5oi4S9oi4s='",
+                config.CDN_HOST
+            ],
+            imgSrc: ["'self'", 'data:', config.CDN_HOST],
+            connectSrc: ["'self'"],
+            formAction: ["'self'"],
+            objectSrc: ["'none'"]
         },
-        contentSecurityPolicy: {
-            useDefaults: true,
-            directives: {
-                defaultSrc: ["'self'"],
-                fontSrc: ["'self'", config.CDN_HOST],
-                styleSrc: ["'self'", "'unsafe-hashes'", "'sha256-6FWIojjtZwiNizws7ImlHjGH3DA5yMh5x4c+/4UVpXk='", config.CDN_HOST],
-                scriptSrc: [
-                    "'self'",
-                    "'sha256-GUQ5ad8JK5KmEWmROf3LZd9ge94daqNvd8xy9YS1iDw='",
-                    "'sha256-rDMP7u4Lf+tIufrYmUZIhcf2T3WBD4Pweu0EXe+qaLA='",
-                    config.CDN_HOST
-                ],
-                imgSrc: ["'self'", 'data:', config.CDN_HOST],
-                connectSrc: ["'self'"],
-                formAction: ["'self'"],
-                objectSrc: ["'none'"]
-            },
-            reportOnly: false
-        }
-    }));
+        reportOnly: false
+    }
+};
+
+export const configureHelmet = (app: express.Application) => {
+    app.use(helmet(HELMET_OPTIONS));
 };

Diff for: src/config/nunjucks.ts

@@ -8,7 +8,7 @@ export const configureNunjucks = (app: express.Application, viewsPath: string) =
     log.info(`Set nunjucks configurations and where nunjucks templates should resolve to: ${viewsPath}`);
 
     const nunjucksEnv = nunjucks.configure(
-        [viewsPath, 'node_modules/govuk-frontend/dist', 'node_modules/govuk-frontend/dist/components'],
+        [viewsPath, 'node_modules/govuk-frontend/dist'],
         {
             autoescape: true,
             express: app

Diff for: src/views/layout.html

@@ -20,10 +20,10 @@
 {% from "govuk/components/notification-banner/macro.njk"    import govukNotificationBanner %}
 
 {% block head %}
-  <link rel="stylesheet" type="text/css" media="all" href="//{{CDN_HOST}}/govuk-frontend/v5.3.0/govuk-frontend-5.3.0.min.css">
+  <link rel="stylesheet" type="text/css" media="all" href="/govuk-frontend.min.css">
 
-  <link rel="SHORTCUT ICON" href="//{{CDN_HOST}}/images/favicon.ico"/>
-  <link rel="icon" href="//{{CDN_HOST}}/images/favicon.ico" type="image/x-icon"/>
+  <link rel="SHORTCUT ICON" href="/assets/images/favicon.ico"/>
+  <link rel="icon" href="/assets/images/favicon.ico" type="image/x-icon"/>
 {% endblock %}
 
 {% block header %}
@@ -85,11 +85,10 @@
 
 {% block bodyEnd %}
   {% if FEATURE_FLAG_ENABLE_COOKIE_BANNER == "true" %}
-    <script src="/assets/javascripts/cookies.js"></script>
+    <script src="//{{CDN_HOST}}/app/github-requests-app/javascripts/cookies.js"></script>
   {% endif %}
-  <script type="module" src="//{{CDN_HOST}}/govuk-frontend/v5.3.0/govuk-frontend-5.3.0.min.js"></script>
   <script type="module">
-    import { initAll } from '//{{CDN_HOST}}/govuk-frontend/v5.3.0/govuk-frontend.min.js'
+    import { initAll } from '/govuk-frontend.min.js'
     initAll()
   </script>
-{% endblock %}
+{% endblock %}

Diff for: test/mock/data.ts

@@ -98,31 +98,6 @@ export const MOCK_ERROR = {
     message: 'Error message'
 } as Error;
 
-export const MOCK_HELMET_VALUE = {
-    referrerPolicy: {
-        policy: 'strict-origin-when-cross-origin'
-    },
-    contentSecurityPolicy: {
-        useDefaults: true,
-        directives: {
-            defaultSrc: ["'self'"],
-            fontSrc: ["'self'", config.CDN_HOST],
-            styleSrc: ["'self'", "'unsafe-hashes'", "'sha256-6FWIojjtZwiNizws7ImlHjGH3DA5yMh5x4c+/4UVpXk='", config.CDN_HOST],
-            scriptSrc: [
-                "'self'",
-                "'sha256-GUQ5ad8JK5KmEWmROf3LZd9ge94daqNvd8xy9YS1iDw='",
-                "'sha256-rDMP7u4Lf+tIufrYmUZIhcf2T3WBD4Pweu0EXe+qaLA='",
-                config.CDN_HOST
-            ],
-            imgSrc: ["'self'", 'data:', config.CDN_HOST],
-            connectSrc: ["'self'"],
-            formAction: ["'self'"],
-            objectSrc: ["'none'"]
-        },
-        reportOnly: false
-    }
-};
-
 export const MOCK_RATE_LIMIT_VALUE = {
     windowMs: 15 * 60 * 1000,
     limit: 100,

Diff for: test/unit/config/helmet.spec.ts

@@ -3,8 +3,8 @@ jest.mock('helmet');
 import { describe, expect, test, jest, afterEach } from '@jest/globals';
 import helmet from 'helmet';
 
-import { configureHelmet } from '../../../src/config/helmet';
-import { MOCK_HELMET_VALUE, MOCK_EXPRESS_APP } from '../../mock/data';
+import { configureHelmet, HELMET_OPTIONS } from '../../../src/config/helmet';
+import { MOCK_EXPRESS_APP } from '../../mock/data';
 
 describe('Helmet Config test suites', () => {
     afterEach(() => {
@@ -17,7 +17,7 @@ describe('Helmet Config test suites', () => {
         configureHelmet(MOCK_EXPRESS_APP);
 
         expect(mockHelmet).toHaveBeenCalledTimes(1);
-        expect(mockHelmet).toHaveBeenCalledWith(MOCK_HELMET_VALUE);
+        expect(mockHelmet).toHaveBeenCalledWith(HELMET_OPTIONS);
         expect(MOCK_EXPRESS_APP.use).toHaveBeenCalled();
     });
 });

Diff for: test/unit/config/nunjucks.spec.ts

@@ -1,7 +1,7 @@
 jest.mock('nunjucks');
 jest.mock('../../../src/utils/logger');
 
-import { describe, expect, test, jest } from '@jest/globals';
+import { describe, expect, afterEach, test, jest } from '@jest/globals';
 
 import * as nunjucks from 'nunjucks';
 
@@ -32,7 +32,7 @@ describe('Nunjucks Configuration test suites', () => {
         configureNunjucks(MOCK_EXPRESS_APP, MOCK_VIEWS_PATH);
 
         expect(nunjucks.configure).toHaveBeenCalledWith(
-            [MOCK_VIEWS_PATH, 'node_modules/govuk-frontend/dist', 'node_modules/govuk-frontend/dist/components'],
+            [MOCK_VIEWS_PATH, 'node_modules/govuk-frontend/dist'],
             {
                 autoescape: true,
                 express: MOCK_EXPRESS_APP