Avoid false check for broadcast emails

Signed-off-by: Marek Libra <marek.libra@gmail.com>

.changeset/flat-guests-behave.md

@@ -0,0 +1,6 @@
+---
+'@backstage/plugin-notifications-backend-module-email': patch
+'@backstage/plugin-notifications-backend': patch
+---
+
+Avoid sending broadcast emails as a fallback in case the entity-typed notification user can not be resolved.

plugins/notifications-backend-module-email/src/processor/NotificationsEmailProcessor.ts

@@ -207,12 +207,17 @@ export class NotificationsEmailProcessor implements NotificationProcessor {
   private async getRecipientEmails(
     notification: Notification,
     options: NotificationSendOptions,
-  ) {
+  ): Promise<string[]> {
     let emails: string[];
-    if (options.recipients.type === 'broadcast' || notification.user === null) {
+    if (options.recipients.type === 'broadcast') {
       emails = await this.getBroadcastEmails();
-    } else {
+    } else if (options.recipients.type === 'entity' && !!notification.user) {
       emails = await this.getUserEmail(notification.user);
+    } else {
+      this.logger.info(
+        `Unknown notification type ${options.recipients.type} or missing user.`,
+      );
+      return [];
     }
 
     if (this.allowlistEmailAddresses) {
@@ -338,6 +343,8 @@ export class NotificationsEmailProcessor implements NotificationProcessor {
       return;
     }
 
+    this.logger.debug(`Sending notification emails to: ${emails.join(',')}`);
+
     if (!this.templateRenderer) {
       await this.sendPlainEmail(notification, emails);
       return;

plugins/notifications-backend/src/service/getUsersForEntityRef.ts

@@ -157,5 +157,5 @@ export const getUsersForEntityRef = async (
     users.push(...u);
   }
 
-  return [...new Set(users)];
+  return [...new Set(users)].filter(Boolean);
 };