fix(server): only send comment mention notification when comment author is doc owner (#13033)

close AF-2711



#### PR Dependency Tree


* **PR #13033** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Tests**
* Added an end-to-end test to verify that mention notifications are
correctly sent when replying to a comment authored by the document
owner.

* **Refactor**
* Improved the notification logic to streamline how mention and owner
notifications are sent, reducing redundancy and ensuring correct
recipients.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/__tests__/e2e/comment/resolver.spec.ts

@@ -744,6 +744,62 @@ e2e(
   }
 );
 
+e2e(
+  'should create reply and send comment mention notification to comment author only when author is doc owner',
+  async t => {
+    const docId = randomUUID();
+    await app.create(Mockers.DocUser, {
+      workspaceId: teamWorkspace.id,
+      docId,
+      userId: member.id,
+      type: DocRole.Owner,
+    });
+
+    await app.login(member);
+    const createResult = await app.gql({
+      query: createCommentMutation,
+      variables: {
+        input: {
+          workspaceId: teamWorkspace.id,
+          docId,
+          docMode: DocMode.page,
+          docTitle: 'test',
+          content: {
+            type: 'paragraph',
+            content: [{ type: 'text', text: 'test' }],
+          },
+        },
+      },
+    });
+
+    await app.login(owner);
+    const count = app.queue.count('notification.sendComment');
+    const result = await app.gql({
+      query: createReplyMutation,
+      variables: {
+        input: {
+          commentId: createResult.createComment.id,
+          docMode: DocMode.page,
+          docTitle: 'test',
+          content: {
+            type: 'paragraph',
+            content: [{ type: 'text', text: 'test' }],
+          },
+        },
+      },
+    });
+
+    t.truthy(result.createReply.id);
+    t.is(result.createReply.commentId, createResult.createComment.id);
+    t.is(app.queue.count('notification.sendComment'), count + 1);
+    const notification = app.queue.last('notification.sendComment');
+    t.is(notification.name, 'notification.sendComment');
+    t.is(notification.payload.userId, member.id);
+    t.is(notification.payload.body.replyId, result.createReply.id);
+    t.is(notification.payload.isMention, true);
+  }
+);
+
 e2e('should create reply work when user is Commenter', async t => {
   const docId = randomUUID();
   await app.create(Mockers.DocUser, {

packages/backend/server/src/core/comment/resolver.ts

@@ -374,14 +374,33 @@ export class CommentResolver {
     mentions?: string[],
     reply?: Reply
   ) {
-    // send comment notification to doc owners
-    const owner = await this.models.docUser.getOwner(
-      comment.workspaceId,
-      comment.docId
-    );
-    if (owner && owner.userId !== sender.id) {
+    const mentionUserIds = new Set(mentions);
+    // send comment mention notification to comment author on reply
+    if (reply) {
+      mentionUserIds.add(comment.userId);
+    }
+
+    // send comment mention notification to mentioned users
+    for (const mentionUserId of mentionUserIds) {
+      // skip if the mention user is the sender
+      if (mentionUserId === sender.id) {
+        continue;
+      }
+
+      // check if the mention user has Doc.Comments.Read permission
+      const hasPermission = await this.ac
+        .user(mentionUserId)
+        .workspace(comment.workspaceId)
+        .doc(comment.docId)
+        .can('Doc.Comments.Read');
+
+      if (!hasPermission) {
+        continue;
+      }
+
       await this.queue.add('notification.sendComment', {
-        userId: owner.userId,
+        isMention: true,
+        userId: mentionUserId,
         body: {
           workspaceId: comment.workspaceId,
           createdByUserId: sender.id,
@@ -396,16 +415,24 @@ export class CommentResolver {
       });
     }
 
-    // send comment mention notification to comment author on reply
-    if (reply && comment.userId !== sender.id) {
+    // send comment notification to doc owners
+    const owner = await this.models.docUser.getOwner(
+      comment.workspaceId,
+      comment.docId
+    );
+    // if the owner is not in the mention user ids, send comment notification to the owner
+    if (
+      owner &&
+      owner.userId !== sender.id &&
+      !mentionUserIds.has(owner.userId)
+    ) {
       await this.queue.add('notification.sendComment', {
-        isMention: true,
-        userId: comment.userId,
+        userId: owner.userId,
         body: {
           workspaceId: comment.workspaceId,
           createdByUserId: sender.id,
           commentId: comment.id,
-          replyId: reply.id,
+          replyId: reply?.id,
           doc: {
             id: comment.docId,
             title: docTitle,
@@ -414,47 +441,6 @@ export class CommentResolver {
         },
       });
     }
-
-    // send comment mention notification to mentioned users
-    if (mentions) {
-      for (const mentionUserId of mentions) {
-        // skip if the mention user is the doc owner or the comment author
-        if (
-          mentionUserId === owner?.userId ||
-          mentionUserId === sender.id ||
-          mentionUserId === comment.userId
-        ) {
-          continue;
-        }
-
-        // check if the mention user has Doc.Comments.Read permission
-        const hasPermission = await this.ac
-          .user(mentionUserId)
-          .workspace(comment.workspaceId)
-          .doc(comment.docId)
-          .can('Doc.Comments.Read');
-
-        if (!hasPermission) {
-          continue;
-        }
-
-        await this.queue.add('notification.sendComment', {
-          isMention: true,
-          userId: mentionUserId,
-          body: {
-            workspaceId: comment.workspaceId,
-            createdByUserId: sender.id,
-            commentId: comment.id,
-            replyId: reply?.id,
-            doc: {
-              id: comment.docId,
-              title: docTitle,
-              mode: docMode,
-            },
-          },
-        });
-      }
-    }
   }
 
   private async assertPermission(