feat(backend): Add one-click unsubscribe endpoints

scripts/newsletter-lib.mjs

@@ -113,11 +113,13 @@ const send = async (test = true) => {
 
     for (let sub of subscribers[lang]) {
       if (l > 0) {
+        const unsubGet = `https://freesewing.org${
+          lang === 'en' ? '/' : '/' + lang + '/'
+        }newsletter/unsubscribe?x=${sub.ehash}`
+        const unsubPost = `https://backend3.freesewing.org/ocunsub/${sub.ehash}`
         const body = mustache.render(template, {
           ...i18n[lang],
-          unsubscribe: `https://freesewing.org${
+          unsubscribe: unsubGet,
-            lang === 'en' ? '/' : '/' + lang + '/'
-          }newsletter/unsubscribe?x=${sub.ehash}`,
           content,
         })
         console.log(`[${lang}] ${l}/${subs} (${i}) Sending to ${sub.email}`)
@@ -141,6 +143,16 @@ const send = async (test = true) => {
                 Charset: 'utf-8',
                 Data: i18n[lang].title,
               },
+              Headers: [
+                {
+                  Name: 'List-Unsubscribe',
+                  Value: unsubPost,
+                },
+                {
+                  Name: 'List-Unsubscribe-Post',
+                  Value: 'List-Unsubscribe=One-Click',
+                },
+              ],
             },
           },
           Destination: {

sites/backend/src/controllers/subscribers.mjs

@@ -1,4 +1,7 @@
 import { SubscriberModel } from '../models/subscriber.mjs'
+// Catch-all page
+import { html as ocunsubOk } from '../html/ocunsub-ok.mjs'
+import { html as ocunsubKo } from '../html/ocunsub-ko.mjs'
 
 export function SubscribersController() {}
 
@@ -47,12 +50,16 @@ SubscribersController.prototype.confirm = async (req, res, tools) => {
 }
 
 /*
- * Unsubscribe from the newsletter
+ * One-Click unsubscribe from the newsletter
  * See: https://freesewing.dev/reference/backend/api
  */
-SubscribersController.unsubscribe = async (req, res, tools) => {
+SubscribersController.prototype.ocunsub = async (req, res, tools) => {
-  const Subscriber = new SubscriberModel(tools)
+  if (!res.params?.ehash) return res.set('Content-Type', 'text/html').status(200).send(ocunsubKo)
-  await Subscriber.unsubscribe(req)
 
-  return Subscriber.sendResponse(res)
+  const Subscriber = new SubscriberModel(tools)
+  const result = await Subscriber.ocunsub(req)
+
+  if (result) return res.set('Content-Type', 'text/html').status(200).send(ocunsubOk)
+
+  return res.set('Content-Type', 'text/html').status(200).send(okunsubKo)
 }

sites/backend/src/html/ocunsub-ko.mjs

@@ -0,0 +1,9 @@
+import { wrapper } from './shared.mjs'
+
+export const html = wrapper({
+  content: `
+<h1><span role="img">🫤</span> FNpe</h1>
+<p>Whatever you intended to do, it did not work.</p>
+<p><a href="https://freesewing.org/support">Contact support</a></p>
+`,
+})

sites/backend/src/html/ocunsub-ok.mjs

@@ -0,0 +1,8 @@
+import { wrapper } from './shared.mjs'
+
+export const html = wrapper({
+  content: `
+<h1><span role="img">👋</span> Farewell</h1>
+<p>You have been unsubscribed.</p>
+`,
+})

sites/backend/src/models/subscriber.mjs

@@ -173,6 +173,43 @@ SubscriberModel.prototype.unsubscribe = async function ({ params }) {
   return this.setResponse(404)
 }
 
+/*
+ * One-click unsubscribe a user
+ * This is an unauthenticated route (has to for newsletter subscribers might not be users)
+ *
+ * @param {body} object - The request body
+ * @returns {SubscriberModal} object - The SubscriberModel
+ */
+SubscriberModel.prototype.ocunsub = async function ({ params }) {
+  const { ehash } = params
+
+  /*
+   * Find the subscription record
+   */
+  await this.read({ ehash })
+
+  /*
+   * If found, remove the record
+   */
+  if (this.record) {
+    await this.delete({ id: this.record.id })
+
+    return true
+  } else {
+    /*
+     * If not, perhaps it's an account ehash rather than subscriber ehash
+     */
+    await this.User.read({ ehash })
+    if (this.User.record) {
+      await this.User.update({ newsletter: false })
+
+      return true
+    }
+  }
+
+  return false
+}
+
 /*
  * A helper method to validate input and load the subscription record
  *

sites/backend/src/routes/subscribers.mjs

@@ -17,4 +17,13 @@ export function subscribersRoutes(tools) {
 
   // Unsubscribe from newsletter
   app.delete('/subscriber/:ehash', (req, res) => Subscriber.unsubscribe(req, res, tools))
+
+  // One-Click unsubscribe (ocunsub) from newsletter needs to be a POST request.
+  // See https://datatracker.ietf.org/doc/html/rfc8058
+  app.post('/ocunsub/:ehash', (req, res) => Subscriber.ocunsub(req, res, tools))
+
+  // Just in case somebody lands here with a GET request
+  app.get('/ocunsub/:ehash', (req, res) =>
+    res.redirect(`https://freesewing.org/newsletter/unsubscribe?i=${req.params.ehash}`)
+  )
 }