From c8ab2e8642b83e08445096d57f4008cbc16a4007 Mon Sep 17 00:00:00 2001
From: Jiang Bohan <bhjiang@outlook.com>
Date: Tue, 31 Mar 2026 18:36:15 +0800
Subject: [PATCH] fix(server): subscribe @mentioned users in issue descriptions

When a user @mentions someone in an issue description (create or update),
the mentioned users were notified via inbox but not added as subscribers.
This adds subscriber registration for mentioned users in both the
issue:created and issue:updated event listeners, mirroring the existing
notification logic.
---
 server/cmd/server/subscriber_listeners.go | 36 +++++++++++++++++++----
 1 file changed, 30 insertions(+), 6 deletions(-)

diff --git a/server/cmd/server/subscriber_listeners.go b/server/cmd/server/subscriber_listeners.go
index 14261e94..42cda006 100644
--- a/server/cmd/server/subscriber_listeners.go
+++ b/server/cmd/server/subscriber_listeners.go
@@ -33,9 +33,16 @@ func registerSubscriberListeners(bus *events.Bus, queries *db.Queries) {
 			!(*issue.AssigneeType == issue.CreatorType && *issue.AssigneeID == issue.CreatorID) {
 			addSubscriber(bus, queries, e.WorkspaceID, issue.ID, *issue.AssigneeType, *issue.AssigneeID, "assignee")
 		}
+
+		// Subscribe @mentioned users in description
+		if issue.Description != nil && *issue.Description != "" {
+			for _, m := range parseMentions(*issue.Description) {
+				addSubscriber(bus, queries, e.WorkspaceID, issue.ID, m.Type, m.ID, "mentioned")
+			}
+		}
 	})
 
-	// issue:updated — subscribe new assignee if assignee changed
+	// issue:updated — subscribe new assignee or @mentioned users
 	bus.Subscribe(protocol.EventIssueUpdated, func(e events.Event) {
 		payload, ok := e.Payload.(map[string]any)
 		if !ok {
@@ -45,13 +52,30 @@ func registerSubscriberListeners(bus *events.Bus, queries *db.Queries) {
 		if !ok {
 			return
 		}
-		assigneeChanged, _ := payload["assignee_changed"].(bool)
-		if !assigneeChanged {
-			return
+
+		// Subscribe new assignee if assignee changed
+		if assigneeChanged, _ := payload["assignee_changed"].(bool); assigneeChanged {
+			if issue.AssigneeType != nil && issue.AssigneeID != nil {
+				addSubscriber(bus, queries, e.WorkspaceID, issue.ID, *issue.AssigneeType, *issue.AssigneeID, "assignee")
+			}
 		}
 
-		if issue.AssigneeType != nil && issue.AssigneeID != nil {
-			addSubscriber(bus, queries, e.WorkspaceID, issue.ID, *issue.AssigneeType, *issue.AssigneeID, "assignee")
+		// Subscribe newly @mentioned users in description
+		if descriptionChanged, _ := payload["description_changed"].(bool); descriptionChanged && issue.Description != nil {
+			newMentions := parseMentions(*issue.Description)
+			if len(newMentions) > 0 {
+				prevMentioned := map[string]bool{}
+				if prevDescription, _ := payload["prev_description"].(*string); prevDescription != nil {
+					for _, m := range parseMentions(*prevDescription) {
+						prevMentioned[m.Type+":"+m.ID] = true
+					}
+				}
+				for _, m := range newMentions {
+					if !prevMentioned[m.Type+":"+m.ID] {
+						addSubscriber(bus, queries, e.WorkspaceID, issue.ID, m.Type, m.ID, "mentioned")
+					}
+				}
+			}
 		}
 	})