Add new Express.js session option

Author: colinrotherham

lib/middleware/index.js

@@ -41,15 +41,16 @@ export function configureSession(options) {
   const sessionName = getSessionName(serviceName)
 
   app.use(
-    session({
-      secret: sessionName,
-      name: sessionName,
-      resave: false,
-      saveUninitialized: true,
-      cookie: {
-        maxAge: SESSION_COOKIE_MAX_AGE
-      }
-    })
+    options.session ??
+      session({
+        secret: sessionName,
+        name: sessionName,
+        resave: false,
+        saveUninitialized: true,
+        cookie: {
+          maxAge: SESSION_COOKIE_MAX_AGE
+        }
+      })
   )
 }
 

lib/nhsuk-prototype-kit.js

@@ -252,6 +252,7 @@ export class NHSPrototypeKit {
  * @property {NunjucksFilters | ((env: Environment) => NunjucksFilters)} [filters] - Additional custom Nunjucks filters
  * @property {object} [config] - Configuration options
  * @property {BuildOptions} [buildOptions] - Build options
+ * @property {RequestHandler} [session] - Middleware to use custom session store
  * @property {{ [key: string]: unknown }} [sessionDataDefaults] - Default data to set in the session
  */
 

lib/nhsuk-prototype-kit.test.js

@@ -4,7 +4,9 @@ import { describe, it, before, mock } from 'node:test'
 import { fileURLToPath } from 'node:url'
 
 import express from 'express'
+import session from 'express-session'
 import nunjucks from 'nunjucks'
+import request from 'supertest'
 
 import { NHSPrototypeKit } from './nhsuk-prototype-kit.js'
 
@@ -96,6 +98,24 @@ describe('NHSPrototypeKit', () => {
       assert.deepEqual(prototype.app, customApp)
     })
 
+    it('should initialize with custom express session', async () => {
+      const genid = mock.fn()
+
+      const customSession = session({
+        saveUninitialized: true,
+        secret: 'Shhh',
+        genid
+      })
+
+      const prototype = await NHSPrototypeKit.init({
+        session: customSession
+      })
+
+      await request(prototype.app).get('/')
+
+      assert.equal(genid.mock.callCount(), 1)
+    })
+
     it('should set express settings', async () => {
       const prototype = await NHSPrototypeKit.init()