MUL-5677: skip squad assignment recipient writes (#6343)

* fix(notifications): skip squad assignment recipient writes

Co-authored-by: multica-agent <github@multica.ai>

* fix(notifications): address squad assignment review nits

Co-authored-by: multica-agent <github@multica.ai>

---------

Co-authored-by: Eve <eve@multica-ai.local>
Co-authored-by: multica-agent <github@multica.ai>

server/cmd/server/notification_listeners.go

@@ -485,7 +485,7 @@ func notifyDirect(
 	})
 	if err != nil {
 		slog.Error("direct notification creation failed",
-			"recipient_id", recipientID, "type", notifType, "error", err)
+			"issue_id", issueID, "recipient_id", recipientID, "type", notifType, "error", err)
 		return
 	}
 
@@ -634,8 +634,8 @@ func registerNotificationListeners(bus *events.Bus, queries *db.Queries) {
 		// Track who already got notified to avoid duplicates
 		skip := map[string]bool{e.ActorID: true}
 
-		// Direct notification to assignee
-		if issue.AssigneeType != nil && issue.AssigneeID != nil {
+		// Direct notification to assignees that own an inbox.
+		if issue.AssigneeType != nil && issue.AssigneeID != nil && isAssignmentRecipientType(*issue.AssigneeType) {
 			skip[*issue.AssigneeID] = true
 			notifyDirect(ctx, queries, bus,
 				*issue.AssigneeType, *issue.AssigneeID,
@@ -697,8 +697,8 @@ func registerNotificationListeners(bus *events.Bus, queries *db.Queries) {
 			}
 			assigneeDetails, _ := json.Marshal(detailsMap)
 
-			// Direct: notify new assignee about assignment
-			if issue.AssigneeType != nil && issue.AssigneeID != nil {
+			// Direct: notify new assignee about assignment when it owns an inbox.
+			if issue.AssigneeType != nil && issue.AssigneeID != nil && isAssignmentRecipientType(*issue.AssigneeType) {
 				notifyDirect(ctx, queries, bus,
 					*issue.AssigneeType, *issue.AssigneeID,
 					e.WorkspaceID, e, issue.ID, issue.Status,
@@ -709,7 +709,9 @@ func registerNotificationListeners(bus *events.Bus, queries *db.Queries) {
 				)
 			}
 
-			// Direct: notify old assignee about unassignment
+			// Direct: notify only a previous member assignee about unassignment.
+			// This is intentionally narrower than isAssignmentRecipientType: agents
+			// do not receive unassigned notifications.
 			if prevAssigneeType != nil && prevAssigneeID != nil && *prevAssigneeType == "member" {
 				notifyDirect(ctx, queries, bus,
 					"member", *prevAssigneeID,

server/cmd/server/squad_assignee_listeners_test.go

@@ -0,0 +1,122 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"log/slog"
+	"strings"
+	"testing"
+
+	"github.com/multica-ai/multica/server/internal/events"
+	"github.com/multica-ai/multica/server/internal/handler"
+	db "github.com/multica-ai/multica/server/pkg/db/generated"
+	"github.com/multica-ai/multica/server/pkg/protocol"
+)
+
+func createAssignmentListenerTestSquad(t *testing.T) string {
+	t.Helper()
+
+	ctx := context.Background()
+	var leaderID string
+	if err := testPool.QueryRow(ctx, `
+		SELECT id::text FROM agent
+		WHERE workspace_id = $1
+		ORDER BY created_at ASC
+		LIMIT 1
+	`, testWorkspaceID).Scan(&leaderID); err != nil {
+		t.Fatalf("load squad leader: %v", err)
+	}
+
+	var squadID string
+	if err := testPool.QueryRow(ctx, `
+		INSERT INTO squad (workspace_id, name, description, leader_id, creator_id)
+		VALUES ($1, 'Squad assignee listener test', '', $2, $3)
+		RETURNING id
+	`, testWorkspaceID, leaderID, testUserID).Scan(&squadID); err != nil {
+		t.Fatalf("create squad: %v", err)
+	}
+	t.Cleanup(func() {
+		if _, err := testPool.Exec(context.Background(), `DELETE FROM squad WHERE id = $1`, squadID); err != nil {
+			t.Errorf("cleanup squad: %v", err)
+		}
+	})
+	return squadID
+}
+
+// A squad is a routing object, not a subscriber or inbox recipient. Both
+// issue event paths must stop before attempting writes that the database
+// constrains to member/agent identities. The log assertion is load-bearing:
+// checking only for zero squad rows would also pass in the broken version
+// because PostgreSQL rejects those rows before the listeners log and return.
+func TestSquadAssigneeListenersSkipUnsupportedRecipientWrites(t *testing.T) {
+	queries := db.New(testPool)
+	bus := events.New()
+	registerSubscriberListeners(bus, testPool)
+	registerNotificationListeners(bus, queries)
+
+	squadID := createAssignmentListenerTestSquad(t)
+	issueID := createTestIssue(t, testWorkspaceID, testUserID)
+	t.Cleanup(func() {
+		cleanupInboxForIssue(t, issueID)
+		cleanupTestIssue(t, issueID)
+	})
+
+	var logs bytes.Buffer
+	previousLogger := slog.Default()
+	slog.SetDefault(slog.New(slog.NewTextHandler(&logs, &slog.HandlerOptions{Level: slog.LevelError})))
+	defer slog.SetDefault(previousLogger)
+
+	assigneeType := "squad"
+	issue := handler.IssueResponse{
+		ID:           issueID,
+		WorkspaceID:  testWorkspaceID,
+		Title:        "squad-assigned issue",
+		Status:       "todo",
+		Priority:     "medium",
+		CreatorType:  "member",
+		CreatorID:    testUserID,
+		AssigneeType: &assigneeType,
+		AssigneeID:   &squadID,
+	}
+
+	bus.Publish(events.Event{
+		Type:        protocol.EventIssueCreated,
+		WorkspaceID: testWorkspaceID,
+		ActorType:   "member",
+		ActorID:     testUserID,
+		Payload:     map[string]any{"issue": issue},
+	})
+	bus.Publish(events.Event{
+		Type:        protocol.EventIssueUpdated,
+		WorkspaceID: testWorkspaceID,
+		ActorType:   "member",
+		ActorID:     testUserID,
+		Payload: map[string]any{
+			"issue":            issue,
+			"assignee_changed": true,
+		},
+	})
+
+	// slog's default logger is process-global. Scope the captured records to
+	// this test's unique issue so unrelated background errors cannot fail it.
+	var issueLogLines []string
+	for _, line := range strings.Split(logs.String(), "\n") {
+		if strings.Contains(line, "issue_id="+issueID) {
+			issueLogLines = append(issueLogLines, line)
+		}
+	}
+	issueLogs := strings.Join(issueLogLines, "\n")
+	for _, unexpected := range []string{
+		"failed to add issue subscriber",
+		"direct notification creation failed",
+		"SQLSTATE 23514",
+	} {
+		if strings.Contains(issueLogs, unexpected) {
+			t.Fatalf("squad assignment attempted an unsupported recipient write (%q):\n%s", unexpected, issueLogs)
+		}
+	}
+
+	if count := subscriberCount(t, queries, issueID); count != 1 {
+		t.Fatalf("subscriber count = %d, want creator only", count)
+	}
+}

server/cmd/server/subscriber_listeners.go

@@ -13,6 +13,13 @@ import (
 	"github.com/multica-ai/multica/server/pkg/protocol"
 )
 
+// isAssignmentRecipientType reports whether an assignee can own a subscriber
+// or inbox row. Squads are routing objects whose work runs through the leader;
+// they are not user identities and have no inbox to consume.
+func isAssignmentRecipientType(assigneeType string) bool {
+	return assigneeType == "member" || assigneeType == "agent"
+}
+
 // registerSubscriberListeners wires up event bus listeners that auto-subscribe
 // relevant users to issues. This ensures creators, assignees, and commenters
 // are automatically tracked as issue subscribers.
@@ -38,8 +45,9 @@ func registerSubscriberListeners(bus *events.Bus, pool *pgxpool.Pool) {
 		// Subscribe the creator
 		addSubscriber(bus, queries, e.WorkspaceID, issue.ID, issue.CreatorType, issue.CreatorID, "creator")
 
-		// Subscribe the assignee if exists and different from creator
+		// Subscribe the assignee if it is a direct recipient and differs from the creator.
 		if issue.AssigneeType != nil && issue.AssigneeID != nil &&
+			isAssignmentRecipientType(*issue.AssigneeType) &&
 			!(*issue.AssigneeType == issue.CreatorType && *issue.AssigneeID == issue.CreatorID) {
 			addSubscriber(bus, queries, e.WorkspaceID, issue.ID, *issue.AssigneeType, *issue.AssigneeID, "assignee")
 		}
@@ -72,7 +80,7 @@ func registerSubscriberListeners(bus *events.Bus, pool *pgxpool.Pool) {
 
 		// Subscribe new assignee if assignee changed
 		if assigneeChanged, _ := payload["assignee_changed"].(bool); assigneeChanged {
-			if issue.AssigneeType != nil && issue.AssigneeID != nil {
+			if issue.AssigneeType != nil && issue.AssigneeID != nil && isAssignmentRecipientType(*issue.AssigneeType) {
 				addSubscriber(bus, queries, e.WorkspaceID, issue.ID, *issue.AssigneeType, *issue.AssigneeID, "assignee")
 			}
 		}