server.js

// Core dependencies
const fs = require('fs');
const path = require('path');

// NPM dependencies
const bodyParser = require('body-parser');
const dotenv = require('dotenv');
const express = require('express');
const nunjucks = require('nunjucks');
const sessionInCookie = require('client-sessions');
const sessionInMemory = require('express-session');
const hljs = require('highlight.js');

// Run before other code to make sure variables from .env are available
dotenv.config();

// Local dependencies
const middleware = [
  require('./lib/middleware/authentication/authentication.js'),
  require('./lib/middleware/extensions/extensions.js'),
];
const config = require('./app/config.js');
const packageJson = require('./package.json');
const routes = require('./app/routes.js');
const utils = require('./lib/utils.js');
const extensions = require('./lib/extensions/extensions.js');
const pages = require('./app/pages');
const tags = require('./app/tags');
const components = require('./app/components');
const {
  bestPracticeFunction,
  wcagTagFunction,
} = require('./app/views/macros/app-tagify/script.js');


// Variables for v6 backwards compatibility
// Set false by default, then turn on if we find /app/v6/routes.js
let useV6 = false;
let v6App;
let v6Routes;

if (fs.existsSync('./app/v6/routes.js')) {
  v6Routes = require('./app/v6/routes.js');
  useV6 = true;
}

const app = express();
const documentationApp = express();

if (useV6) {
  console.log('/app/v6/routes.js detected - using v6 compatibility mode');
  v6App = express();
}

// Set up configuration variables
const releaseVersion = packageJson.version;
const glitchEnv = process.env.PROJECT_REMIX_CHAIN ? 'production' : false; // glitch.com
const env = (
  process.env.NODE_ENV ||
  glitchEnv ||
  'development'
).toLowerCase();
const useAutoStoreData =
  process.env.USE_AUTO_STORE_DATA || config.useAutoStoreData;
const useCookieSessionStore =
  process.env.USE_COOKIE_SESSION_STORE || config.useCookieSessionStore;
let useHttps = process.env.USE_HTTPS || config.useHttps;

useHttps = useHttps.toLowerCase();

const useDocumentation = config.useDocumentation === 'true';

// Promo mode redirects the root to /docs - so our landing page is docs when published on heroku
let promoMode = process.env.PROMO_MODE || 'false';
promoMode = promoMode.toLowerCase();

// Disable promo mode if docs aren't enabled
if (!useDocumentation) promoMode = 'false';

// Force HTTPS on production. Do this before using basicAuth to avoid
// asking for username/password twice (for `http`, then `https`).
const isSecure = env === 'production' && useHttps === 'true';
if (isSecure) {
  app.use(utils.forceHttps);
  app.set('trust proxy', 1); // needed for secure cookies on heroku
}

middleware.forEach((func) => app.use(func));
require('@cypress/code-coverage/middleware/express')(app);

// Set up App
const appViews = extensions.getAppViews([
  path.join(__dirname, '/app/views/'),
  path.join(__dirname, '/lib/'),
]);

const nunjucksConfig = {
  autoescape: true,
  noCache: true,
  watch: false, // We are now setting this to `false` (it's by default false anyway) as having it set to `true` for production was making the tests hang
};

if (env === 'development') {
  nunjucksConfig.watch = true;
}

nunjucksConfig.express = app;

const nunjucksAppEnv = nunjucks.configure(appViews, nunjucksConfig);

// Add Nunjucks filters
utils.addNunjucksFilters(nunjucksAppEnv);

// Set views engine
app.set('view engine', 'html');

// Middleware to serve static assets
app.use('/public', express.static(path.join(__dirname, '/public')));

// Serve govuk-frontend in from node_modules (so not to break pre-extensions prototype kits)
app.use(
  '/node_modules/govuk-frontend',
  express.static(path.join(__dirname, '/node_modules/govuk-frontend'))
);

// Set up documentation app
if (useDocumentation) {
  const documentationViews = [
    path.join(__dirname, '/node_modules/govuk-frontend/'),
    path.join(__dirname, '/node_modules/govuk-frontend/components'),
    path.join(__dirname, '/docs/views/'),
    path.join(__dirname, '/lib/'),
  ];

  nunjucksConfig.express = documentationApp;
  var nunjucksDocumentationEnv = nunjucks.configure(
    documentationViews,
    nunjucksConfig
  );
  // Nunjucks filters
  utils.addNunjucksFilters(nunjucksDocumentationEnv);

  // Set views engine
  documentationApp.set('view engine', 'html');
}

// Support for parsing data in POSTs
app.use(bodyParser.json());
app.use(
  bodyParser.urlencoded({
    extended: true,
  })
);

// Set up v6 app for backwards compatibility
if (useV6) {
  const v6Views = [
    path.join(__dirname, '/node_modules/govuk_template_jinja/views/layouts'),
    path.join(__dirname, '/app/v6/views/'),
    path.join(__dirname, '/lib/v6'), // for old unbranded template
  ];
  nunjucksConfig.express = v6App;
  var nunjucksV6Env = nunjucks.configure(v6Views, nunjucksConfig);

  // Nunjucks filters
  utils.addNunjucksFilters(nunjucksV6Env);

  // Set views engine
  v6App.set('view engine', 'html');

  // Backward compatibility with GOV.UK Elements
  app.use(
    '/public/v6/',
    express.static(
      path.join(__dirname, '/node_modules/govuk_template_jinja/assets')
    )
  );
  app.use(
    '/public/v6/',
    express.static(
      path.join(__dirname, '/node_modules/govuk_frontend_toolkit')
    )
  );
  app.use(
    '/public/v6/javascripts/govuk/',
    express.static(
      path.join(
        __dirname,
        '/node_modules/govuk_frontend_toolkit/javascripts/govuk/'
      )
    )
  );
}

// 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.promoMode = promoMode;
app.locals.releaseVersion = 'v' + releaseVersion;
app.locals.serviceName = config.serviceName;
app.locals.titleSuffix = config.titleSuffix;
// extensionConfig sets up variables used to add the scripts and stylesheets to each page.
app.locals.extensionConfig = extensions.getAppConfig();
app.locals.page = pages;
app.locals.tags = tags;
app.locals.components = components;
// Session uses service name to avoid clashes with other prototypes
const sessionName =
  'govuk-prototype-kit-' +
  Buffer.from(config.serviceName, 'utf8').toString('hex');
const sessionOptions = {
  secret: sessionName,
  cookie: {
    maxAge: 1000 * 60 * 60 * 4, // 4 hours
    secure: isSecure,
  },
};

// Support session data in cookie or memory
if (useCookieSessionStore === 'true') {
  app.use(
    sessionInCookie(
      Object.assign(sessionOptions, {
        cookieName: sessionName,
        proxy: true,
        requestKey: 'session',
      })
    )
  );
} else {
  app.use(
    sessionInMemory(
      Object.assign(sessionOptions, {
        name: sessionName,
        resave: false,
        saveUninitialized: false,
      })
    )
  );
}

// Automatically store all data users enter
if (useAutoStoreData === 'true') {
  app.use(utils.autoStoreData);
  utils.addCheckedFunction(nunjucksAppEnv);
  if (useDocumentation) {
    utils.addCheckedFunction(nunjucksDocumentationEnv);
  }
  if (useV6) {
    utils.addCheckedFunction(nunjucksV6Env);
  }
}

// Clear all data in session if you open /prototype-admin/clear-data
app.post('/prototype-admin/clear-data', function (req, res) {
  req.session.data = {};
  res.render('prototype-admin/clear-data-success');
});

// Redirect root to /docs when in promo mode.
if (promoMode === 'true') {
  console.log('Prototype Kit running in promo mode');

  app.get('/', function (req, res) {
    res.redirect('/docs');
  });

  // Allow search engines to index the Prototype Kit promo site
  app.get('/robots.txt', function (req, res) {
    res.type('text/plain');
    res.send('User-agent: *\nAllow: /');
  });
} else {
  // Prevent search indexing
  app.use(function (req, res, next) {
    // Setting headers stops pages being indexed even if indexed pages link to them.
    res.setHeader('X-Robots-Tag', 'noindex');
    next();
  });

  app.get('/robots.txt', function (req, res) {
    res.type('text/plain');
    res.send('User-agent: *\nDisallow: /');
  });
}

// Load routes (found in app/routes.js)
if (typeof routes !== 'function') {
  console.log(routes.bind);
  console.log(
    'Warning: the use of bind in routes is deprecated - please check the Prototype Kit documentation for writing routes.'
  );
  routes.bind(app);
} else {
  app.use('/', routes);
}

if (useV6) {
  // Clone app locals to v6 app locals
  v6App.locals = Object.assign({}, app.locals);
  v6App.locals.asset_path = '/public/v6/';

  // Create separate router for v6
  app.use('/', v6App);

  // Docs under the /docs namespace
  v6App.use('/', v6Routes);
}

// Strip .html and .htm if provided
app.get(/\.html?$/i, function (req, res) {
  let path = req.path;
  const parts = path.split('.');
  parts.pop();
  path = parts.join('.');
  res.redirect(path);
});

// Auto render any view that exists

// App folder routes get priority
app.get(/^([^.]+)$/, function (req, res, next) {
  utils.matchRoutes(req, res, next);
});

if (useDocumentation) {
  // Documentation  routes
  documentationApp.get(/^([^.]+)$/, function (req, res, next) {
    if (!utils.matchMdRoutes(req, res)) {
      utils.matchRoutes(req, res, next);
    }
  });
}

if (useV6) {
  // App folder routes get priority
  v6App.get(/^([^.]+)$/, function (req, res, next) {
    utils.matchRoutes(req, res, next);
  });
}

// Redirect all POSTs to GETs - this allows users to use POST for autoStoreData
app.post(/^\/([^.]+)$/, function (req, res) {
  res.redirect('/' + req.params[0]);
});

// Catch 404 and forward to error handler
app.use(function (req, res, next) {
  const err = new Error(`Page not found: ${req.path}`);
  err.status = 404;
  next(err);
});

// Display error
app.use(function (err, req, res, next) {
  console.error(err.message);
  res.status(err.status || 500);
  res.send(err.message);
});

console.log('\nGOV.UK Prototype Kit v' + releaseVersion);
console.log(
  '\nNOTICE: the kit is for building prototypes, do not use it for production services.'
);

module.exports = app;