Merge pull request #32619 from kaidubauskas-dd/kaidd/fix-user-slack-dms

fix(notifications-slack): Only DM explicit user recipients

.changeset/curvy-socks-punch.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-notifications-backend-module-slack': minor
+---
+
+**BREAKING**: Only send direct messages to user entity recipients. Notifications sent to non-user entities no longer send Slack direct messages to resolved users.

plugins/notifications-backend-module-slack/src/lib/SlackNotificationProcessor.test.ts

@@ -355,6 +355,51 @@ describe('SlackNotificationProcessor', () => {
     });
   });
 
+  describe('when recipients include both users and a group', () => {
+    it('should still DM explicit user recipients', async () => {
+      const slack = new WebClient();
+
+      const processor = SlackNotificationProcessor.fromConfig(config, {
+        auth,
+        logger,
+        catalog: catalogServiceMock({
+          entities: DEFAULT_ENTITIES_RESPONSE.items,
+        }),
+        slack,
+      })[0];
+
+      await processor.processOptions({
+        recipients: {
+          type: 'entity',
+          entityRef: ['group:default/mock', 'user:default/mock'],
+        },
+        payload: { title: 'notification' },
+      });
+
+      await processor.postProcess(
+        {
+          origin: 'plugin',
+          id: 'explicit-user-1',
+          user: 'user:default/mock',
+          created: new Date(),
+          payload: { title: 'notification' },
+        },
+        {
+          recipients: {
+            type: 'entity',
+            entityRef: ['group:default/mock', 'user:default/mock'],
+          },
+          payload: { title: 'notification' },
+        },
+      );
+
+      expect(slack.chat.postMessage).toHaveBeenCalledTimes(2);
+      expect(slack.chat.postMessage).toHaveBeenCalledWith(
+        expect.objectContaining({ channel: 'U12345678' }),
+      );
+    });
+  });
+
   describe('when broadcast channels are not configured', () => {
     it('should not send broadcast messages', async () => {
       const slack = new WebClient();

plugins/notifications-backend-module-slack/src/lib/SlackNotificationProcessor.ts

@@ -19,6 +19,7 @@ import {
   Entity,
   isUserEntity,
   parseEntityRef,
+  stringifyEntityRef,
   UserEntity,
 } from '@backstage/catalog-model';
 import { Config, readDurationFromConfig } from '@backstage/config';
@@ -280,8 +281,15 @@ export class SlackNotificationProcessor implements NotificationProcessor {
     } else if (options.recipients.type === 'entity') {
       // Handle user-specific notification
       const entityRefs = [options.recipients.entityRef].flat();
-      if (entityRefs.some(e => parseEntityRef(e).kind === 'group')) {
-        // We've already dispatched a slack channel message, so let's not send a DM.
+      const explicitUserEntityRefs = entityRefs
+        .filter(entityRef => parseEntityRef(entityRef).kind === 'user')
+        .map(entityRef => stringifyEntityRef(parseEntityRef(entityRef)));
+      const normalizedUserRef = stringifyEntityRef(
+        parseEntityRef(notification.user),
+      );
+
+      if (!explicitUserEntityRefs.includes(normalizedUserRef)) {
+        // This user was resolved from a non-user entity. Skip sending a DM.
         return;
       }