feat: notify admins when a thread has 100 messages 🚨 (#605)

colorstackorg · Dec 7, 2024 · ee5e738 · ee5e738
1 parent 4ab0538
commit ee5e738
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Showing 4 changed files with 40 additions and 6 deletions.
diff --git a/apps/api/src/routers/slack.router.ts b/apps/api/src/routers/slack.router.ts
@@ -110,6 +110,7 @@ slackEventRouter.post('/slack/events', async (req: RawBodyRequest, res) => {
         hasFile: !!event.files && !!event.files.length,
         id: event.ts!,
         isBot: !!event.app_id || !!event.bot_id,
+        replyCount: event.message?.reply_count,
         text: event.text!,
         threadId:
           event.ts && event.thread_ts && event.ts !== event.thread_ts

diff --git a/apps/api/src/routers/slack.types.ts b/apps/api/src/routers/slack.types.ts
@@ -58,12 +58,17 @@ type SlackMessageDeletedEvent = {
 
 /**
  * @see https://api.slack.com/events/message
+ * @see https://api.slack.com/events/message/message_replied
  */
 type SlackMessageSentEvent = {
   app_id?: string;
   bot_id?: string;
   channel: string;
   files?: unknown[];
+  message?: {
+    // Only present if the message is a reply.
+    reply_count?: number;
+  };
   subtype: undefined;
   text: string;
   thread_ts: string | undefined;

diff --git a/packages/core/src/infrastructure/bull/bull.types.ts b/packages/core/src/infrastructure/bull/bull.types.ts
@@ -490,6 +490,7 @@ export const SlackBullJob = z.discriminatedUnion('name', [
     }).extend({
       hasFile: z.boolean().optional(),
       isBot: z.boolean().optional(),
+      replyCount: z.number().int().optional(),
     }),
   }),
   z.object({

diff --git a/packages/core/src/modules/slack/use-cases/add-slack-message.ts b/packages/core/src/modules/slack/use-cases/add-slack-message.ts
@@ -4,13 +4,14 @@ import { type GetBullJobData } from '@/infrastructure/bull/bull.types';
 import { job } from '@/infrastructure/bull/use-cases/job';
 import { redis } from '@/infrastructure/redis';
 import { isFeatureFlagEnabled } from '@/modules/feature-flag/queries/is-feature-flag-enabled';
+import { slack } from '@/modules/slack/instances';
 import { ErrorWithContext } from '@/shared/errors';
 import { retryWithBackoff } from '@/shared/utils/core.utils';
 import { getSlackMessage } from '../services/slack-message.service';
 
-export async function addSlackMessage(
-  data: GetBullJobData<'slack.message.add'>
-) {
+type AddSlackMessageInput = GetBullJobData<'slack.message.add'>;
+
+export async function addSlackMessage(data: AddSlackMessageInput) {
   await ensureThreadExistsIfNecessary(data);
 
   const student = await db
@@ -53,6 +54,14 @@ export async function addSlackMessage(
     threadId: data.threadId || data.id,
   });
 
+  if (data.replyCount === 100) {
+    // We don't need to await this since it's not a critical path.
+    notifyBusySlackThread({
+      channelId: data.channelId,
+      id: data.id,
+    });
+  }
+
   // We'll do some additional checks for top-level threads...
   if (!data.threadId) {
     const [
@@ -111,9 +120,7 @@ export async function addSlackMessage(
   }
 }
 
-async function ensureThreadExistsIfNecessary(
-  data: GetBullJobData<'slack.message.add'>
-) {
+async function ensureThreadExistsIfNecessary(data: AddSlackMessageInput) {
   // Don't need to bother if there is no thread.
   if (!data.threadId) {
     return;
@@ -174,3 +181,23 @@ async function ensureThreadExistsIfNecessary(
     }
   );
 }
+
+/**
+ * Sends a notification to the internal team when a thread gets over 100
+ * replies. The motivation is that some threads can get a little too spicy
+ * and we want to moderate them quickly in case of abuse.
+ */
+async function notifyBusySlackThread({
+  channelId,
+  id,
+}: Pick<AddSlackMessageInput, 'channelId' | 'id'>) {
+  const { permalink } = await slack.chat.getPermalink({
+    channel: channelId,
+    message_ts: id,
+  });
+
+  job('notification.slack.send', {
+    message: `🚨 Heads up! This <${permalink}|thread> has over 💯 replies!`,
+    workspace: 'internal',
+  });
+}