NHSDigital · frankieroberto · Nov 11, 2025 · Nov 11, 2025 · Nov 11, 2025 · Nov 11, 2025
diff --git a/app.js b/app.js
@@ -1,346 +1,48 @@
-// Suppress deprecation warning from dependencies using util.isArray
-process.noDeprecation = true
-
-// Core dependencies
-const {
-  createReadStream,
-  createWriteStream,
-  existsSync,
-  mkdirSync,
-  readdirSync,
-  unlinkSync
-} = require('node:fs')
-const { join } = require('node:path')
-const { format: urlFormat } = require('node:url')
-
-// External dependencies
-const bodyParser = require('body-parser')
-const sessionInCookie = require('client-sessions')
-const flash = require('connect-flash')
-const cookieParser = require('cookie-parser')
-const dotenv = require('dotenv')
-const express = require('express')
-const sessionInMemory = require('express-session')
-const nunjucks = require('nunjucks')
-const sessionInFiles = require('session-file-store')
-
-// Run before other code to make sure variables from .env are available
-dotenv.config({
-  quiet: true
-})
+const NHSPrototypeKit = require('nhsuk-prototype-kit')
 
 // Local dependencies
 const config = require('./app/config')
 const locals = require('./app/locals')
 const routes = require('./app/routes')
-const exampleTemplatesRoutes = require('./lib/example_templates_routes')
-const authentication = require('./lib/middleware/authentication')
-const automaticRouting = require('./lib/middleware/auto-routing')
-const environmentMiddleware = require('./app/lib/middleware/environment')
-const production = require('./lib/middleware/production')
-const prototypeAdminRoutes = require('./lib/middleware/prototype-admin-routes')
-const utils = require('./lib/utils')
-const packageInfo = require('./package.json')
+const sessionDataDefaults = require('./app/data/session-data-defaults')
+const filters = require('./app/filters')
+
+const SERVICE_NAME = config.serviceName
 
 // Set configuration variables
 const port = parseInt(process.env.PORT || config.port, 10) || 2000
 
 // Initialise applications
-const app = express()
-const exampleTemplatesApp = express()
-
-// Set up configuration variables
-const useAutoStoreData =
-  process.env.USE_AUTO_STORE_DATA || config.useAutoStoreData
-const useCookieSessionStore =
-  process.env.USE_COOKIE_SESSION_STORE || config.useCookieSessionStore
-
-// Add variables that are available in all views
-app.locals.asset_path = '/public/'
-app.locals.useAutoStoreData = useAutoStoreData === 'true'
-app.locals.useCookieSessionStore = useCookieSessionStore === 'true'
-app.locals.serviceName = config.serviceName
-
-// Use cookie middleware to parse cookies
-app.use(cookieParser())
-
-// Nunjucks configuration for application
-const appViews = [
-  join(__dirname, 'app/views/'),
-  join(__dirname, 'app/views/_templates'),
-  join(__dirname, 'app/views/_includes'),
-  join(__dirname, 'lib/example-templates/'),
-  join(__dirname, 'lib/prototype-admin/'),
-  join(__dirname, 'lib/templates/'),
-  join(__dirname, 'node_modules/nhsuk-frontend/dist/nhsuk/components'),
-  join(__dirname, 'node_modules/nhsuk-frontend/dist/nhsuk/macros'),
-  join(__dirname, 'node_modules/nhsuk-frontend/dist/nhsuk'),
-  join(__dirname, 'node_modules/nhsuk-frontend/dist')
+const viewsPath = [
+  'app/views/',
+  'app/views/_templates/',
+  'app/views/_includes'
 ]
 
-/**
- * @type {ConfigureOptions}
- */
-const nunjucksConfig = {
-  autoescape: true,
-  noCache: true
-}
-
-nunjucksConfig.express = app
-
-let nunjucksAppEnv = nunjucks.configure(appViews, nunjucksConfig)
-nunjucksAppEnv.addGlobal('version', packageInfo.version)
-
-// Add Nunjucks filters
-utils.addNunjucksFilters(nunjucksAppEnv)
-
-// Session uses service name to avoid clashes with other prototypes
-const sessionName = `nhsuk-prototype-kit-${Buffer.from(config.serviceName, 'utf8').toString('hex')}`
-const sessionOptions = {
-  secret: sessionName,
-  cookie: {
-    maxAge: 1000 * 60 * 60 * 1 // 1 hour (reduced from 4 to limit session accumulation)
-  }
-}
-
-if (process.env.NODE_ENV === 'production') {
-  app.use(production)
-  app.use(authentication)
-}
-
-// Support session data in cookie or memory
-if (useCookieSessionStore === 'true') {
-  app.use(
-    sessionInCookie({
-      ...sessionOptions,
-      cookieName: sessionName,
-      proxy: true,
-      requestKey: 'session'
-    })
-  )
-} else {
-  // app.use(
-  //   sessionInMemory({
-  //     ...sessionOptions,
-  //     name: sessionName,
-  //     resave: false,
-  //     saveUninitialized: false
-  //   })
-  // )
-
-  // Somewhat similar file store to GOV.UK
-  const FileStore = sessionInFiles(sessionInMemory)
-  const sessionPath = join(__dirname, '.tmp/sessions')
-
-  // Make sure the sessions directory exists
-  if (!existsSync(sessionPath)) {
-    mkdirSync(sessionPath, { recursive: true })
-  } else {
-    // Clear existing session files on restart
-    readdirSync(sessionPath).forEach((file) => {
-      unlinkSync(join(sessionPath, file))
-    })
-  }
-
-  // app.use(
-  //   sessionInMemory({
-  //     ...sessionOptions,
-  //     name: sessionName,
-  //     resave: false,
-  //     saveUninitialized: false,
-  //     store: new FileStore({
-  //       path: sessionPath,
-  //       logFn: (message) => {
-  //         // Suppress all expected session-related messages
-  //         if (
-  //           message.endsWith('Deleting expired sessions') ||
-  //           message.includes('ENOENT')
-  //         ) {
-  //           return
-  //         }
-  //         // Only log unexpected issues
-  //         console.log(message)
-  //       }
-  //     })
-  //   })
-  // )
-  // Support session data in cookie or memory
-  if (useCookieSessionStore === 'true') {
-    app.use(
-      sessionInCookie({
-        ...sessionOptions,
-        cookieName: sessionName,
-        proxy: true,
-        requestKey: 'session'
-      })
-    )
-  } else {
-    app.use(
-      sessionInMemory({
-        ...sessionOptions,
-        name: sessionName,
-        resave: false,
-        saveUninitialized: false
-      })
-    )
-  }
-}
-
-// Support for parsing data in POSTs
-app.use(bodyParser.json())
-app.use(
-  bodyParser.urlencoded({
-    extended: true
+async function init() {
+  const prototype = await NHSPrototypeKit.init({
+    serviceName: SERVICE_NAME,
+    buildOptions: {
+      entryPoints: [
+        'app/assets/sass/main.scss',
+        'app/assets/javascript/*.js'
+      ]
+    },
+    viewsPath,
+    routes,
+    locals,
+    sessionDataDefaults
   })
-)
 
-// Automatically store all data users enter
-if (useAutoStoreData === 'true') {
-  app.use(utils.autoStoreData)
-  utils.addCheckedFunction(nunjucksAppEnv)
-}
+  // Add custom port number
+  prototype.app?.set('port', config.port)
 
-app.use(utils.setLocals)
-
-// Flash messages
-app.use(flash())
-
-// Warn if node_modules folder doesn't exist
-function checkFiles() {
-  const nodeModulesExists = existsSync(join(__dirname, '/node_modules'))
-  if (!nodeModulesExists) {
-    throw new Error(
-      'ERROR: Node module folder missing. Try running `npm install`'
-    )
+  // Add custom Nunjucks filters
+  for (const [name, filter] of Object.entries(filters())) {
+    prototype.nunjucks?.addFilter(name, filter)
   }
 
-  // Create template .env file if it doesn't exist
-  const envExists = existsSync(join(__dirname, '/.env'))
-  if (!envExists) {
-    createReadStream(join(__dirname, '/lib/template.env')).pipe(
-      createWriteStream(join(__dirname, '/.env'))
-    )
-  }
+  prototype.start()
 }
 
-// initial checks
-checkFiles()
-
-// Create template session data defaults file if it doesn't exist
-const dataDirectory = join(__dirname, '/app/data')
-const sessionDataDefaultsFile = join(dataDirectory, '/session-data-defaults.js')
-const sessionDataDefaultsFileExists = existsSync(sessionDataDefaultsFile)
-
-if (!sessionDataDefaultsFileExists) {
-  console.log('Creating session data defaults file')
-  if (!existsSync(dataDirectory)) {
-    mkdirSync(dataDirectory)
-  }
-
-  createReadStream(
-    join(__dirname, '/lib/template.session-data-defaults.js')
-  ).pipe(createWriteStream(sessionDataDefaultsFile))
-}
-
-// Local variables
-app.use(locals(config))
-
-// Environment banner
-app.use(environmentMiddleware)
-
-// View engine
-app.set('view engine', 'html')
-exampleTemplatesApp.set('view engine', 'html')
-
-// Support for parsing nested query strings
-// https://github.com/nhsuk/nhsuk-prototype-kit/issues/644
-app.set('query parser', 'extended')
-
-// This setting trusts the X-Forwarded headers set by
-// a proxy and uses them to set the standard header in
-// req. This is needed for hosts like Heroku.
-// See https://expressjs.com/en/guide/behind-proxies.html
-app.set('trust proxy', 1)
-
-// Use public folder for static assets
-app.use(express.static(join(__dirname, 'public')))
-
-// Use assets from NHS frontend
-app.use(
-  '/nhsuk-frontend',
-  express.static(join(__dirname, 'node_modules/nhsuk-frontend/dist/nhsuk'))
-)
-
-// Use custom application routes
-app.use('/', routes)
-
-// Automatically route pages
-app.get(/^([^.]+)$/, (req, res, next) => {
-  automaticRouting.matchRoutes(req, res, next)
-})
-
-// Example template routes
-app.use('/example-templates', exampleTemplatesApp)
-
-nunjucksAppEnv = nunjucks.configure(appViews, {
-  autoescape: true,
-  express: exampleTemplatesApp
-})
-nunjucksAppEnv.addGlobal('version', packageInfo.version)
-
-// Add Nunjucks filters
-utils.addNunjucksFilters(nunjucksAppEnv)
-
-exampleTemplatesApp.use('/', exampleTemplatesRoutes)
-
-// Automatically route example template pages
-exampleTemplatesApp.get(/^([^.]+)$/, (req, res, next) => {
-  automaticRouting.matchRoutes(req, res, next)
-})
-
-app.use('/prototype-admin', prototypeAdminRoutes)
-
-// Redirect all POSTs to GETs - this allows users to use POST for autoStoreData
-app.post(/^\/([^.]+)$/, (req, res) => {
-  res.redirect(
-    urlFormat({
-      pathname: `/${req.params[0]}`,
-      query: req.query
-    })
-  )
-})
-
-// Catch 404 and forward to error handler
-app.use((req, res, next) => {
-  const err = new Error(`Page not found: ${req.path}`)
-  err.status = 404
-  next(err)
-})
-
-// Display error
-app.use((err, req, res) => {
-  console.error(err.message)
-  res.status(err.status || 500)
-  res.send(err.message)
-})
-
-// Run the application
-app.listen(port)
-
-if (
-  process.env.WATCH !== 'true' && // If the user isn’t running watch
-  process.env.NODE_ENV !== 'production' // and it’s not in production mode
-) {
-  console.info(`Running at http://localhost:${port}/`)
-  console.info('')
-  console.warn(
-    'Warning: It looks like you may have run the command `npm start` locally.'
-  )
-  console.warn('Press `Ctrl+C` and then run `npm run watch` instead')
-}
-
-module.exports = app
-
-/**
- * @import { ConfigureOptions } from 'nunjucks'
- */
+init()