feat: Debounce notification emails by 5 minutes to avoid duplicate notifications where possible (#1598)

server/api/notificationSettings.js

@@ -2,7 +2,7 @@
 import Router from "koa-router";
 
 import auth from "../middlewares/authentication";
-import { NotificationSetting } from "../models";
+import { Team, NotificationSetting } from "../models";
 import policy from "../policies";
 import { presentNotificationSetting } from "../presenters";
 
@@ -62,16 +62,23 @@ router.post("notificationSettings.unsubscribe", async (ctx) => {
   ctx.assertUuid(id, "id is required");
   ctx.assertPresent(token, "token is required");
 
-  const setting = await NotificationSetting.findByPk(id);
-  if (setting) {
-    if (token !== setting.unsubscribeToken) {
-      ctx.redirect(`${process.env.URL}?notice=invalid-auth`);
-    }
+  const setting = await NotificationSetting.findByPk(id, {
+    include: [
+      {
+        model: Team,
+        required: true,
+        as: "team",
+      },
+    ],
+  });
 
+  if (setting && setting.unsubscribeToken === token) {
     await setting.destroy();
+    ctx.redirect(`${setting.team.url}/settings/notifications?success`);
+    return;
   }
 
-  ctx.redirect(`${process.env.URL}/settings/notifications?success`);
+  ctx.redirect(`${process.env.URL}?notice=invalid-auth`);
 });
 
 export default router;

server/services/notifications.js

@@ -1,4 +1,5 @@
 // @flow
+import * as Sentry from "@sentry/node";
 import type { DocumentEvent, CollectionEvent, Event } from "../events";
 import mailer from "../mailer";
 import {
@@ -9,29 +10,21 @@ import {
   NotificationSetting,
 } from "../models";
 import { Op } from "../sequelize";
+import { createQueue } from "../utils/queue";
 
-export default class Notifications {
-  async on(event: Event) {
-    switch (event.name) {
-      case "documents.publish":
-      case "documents.update":
-        return this.documentUpdated(event);
-      case "collections.create":
-        return this.collectionCreated(event);
-      default:
-    }
-  }
+const notificationsQueue = createQueue("notifications");
 
-  async documentUpdated(event: DocumentEvent) {
-    // lets not send a notification on every autosave update
-    if (event.data && event.data.autosave) return;
-
-    // wait until the user has finished editing
-    if (event.data && !event.data.done) return;
+notificationsQueue.process(async (job) => {
+  const event = job.data;
 
+  try {
     const document = await Document.findByPk(event.documentId);
     if (!document) return;
 
+    // If the document has been updated since we initially queued a notification
+    // abort sending a notification – this functions as a debounce.
+    if (document.updatedAt > new Date(event.createdAt)) return;
+
     const { collection } = document;
     if (!collection) return;
 
@@ -79,6 +72,35 @@ export default class Notifications {
         unsubscribeUrl: setting.unsubscribeUrl,
       });
     });
+  } catch (error) {
+    if (process.env.SENTRY_DSN) {
+      Sentry.withScope(function (scope) {
+        scope.setExtra("event", event);
+        Sentry.captureException(error);
+      });
+    } else {
+      throw error;
+    }
+  }
+});
+
+export default class Notifications {
+  async on(event: Event) {
+    switch (event.name) {
+      case "documents.publish":
+      case "documents.update":
+        return this.documentUpdated(event);
+      case "collections.create":
+        return this.collectionCreated(event);
+      default:
+    }
+  }
+
+  async documentUpdated(event: DocumentEvent) {
+    notificationsQueue.add(event, {
+      delay: 5 * 60 * 1000,
+      removeOnComplete: true,
+    });
   }
 
   async collectionCreated(event: CollectionEvent) {