From e60c656e7cef10a0676843099224d97573925b7e Mon Sep 17 00:00:00 2001
From: Ryan Oaks <ryanoaks@google.com>
Date: Fri, 15 Mar 2024 10:59:43 -0400
Subject: [PATCH] Modify issue labeler to skip linked issues (#10199)

* Modify issue labeler to skip linked issues

* Update tests
---
 tools/issue-labeler/labeler/backfill.go      |  8 ++++++++
 tools/issue-labeler/labeler/backfill_test.go | 12 +++---------
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/tools/issue-labeler/labeler/backfill.go b/tools/issue-labeler/labeler/backfill.go
index 12db0cc04238..89eed2d58077 100644
--- a/tools/issue-labeler/labeler/backfill.go
+++ b/tools/issue-labeler/labeler/backfill.go
@@ -98,6 +98,14 @@ func ComputeIssueUpdates(issues []Issue, regexpLabels []RegexpLabel) []IssueUpda
 			continue
 		}
 
+		// Decision was made to no longer add new service labels to linked tickets, because it is
+		// more difficult to know which teams have received those tickets and which haven't.
+		// Forwarding a ticket to a different service team should involve removing the old service
+		// label and `linked` label.
+		if linked {
+			continue
+		}
+
 		var issueUpdate IssueUpdate
 		for label := range desired {
 			issueUpdate.OldLabels = append(issueUpdate.OldLabels, label)
diff --git a/tools/issue-labeler/labeler/backfill_test.go b/tools/issue-labeler/labeler/backfill_test.go
index c58e7f14b8e6..36ffa8defee3 100644
--- a/tools/issue-labeler/labeler/backfill_test.go
+++ b/tools/issue-labeler/labeler/backfill_test.go
@@ -136,7 +136,7 @@ func TestComputeIssueUpdates(t *testing.T) {
 				},
 			},
 		},
-		"add missing service labels even if already linked": {
+		"don't add missing service labels if already linked": {
 			issues: []Issue{
 				{
 					Number:      1,
@@ -145,14 +145,8 @@ func TestComputeIssueUpdates(t *testing.T) {
 					PullRequest: map[string]any{},
 				},
 			},
-			regexpLabels: defaultRegexpLabels,
-			expectedIssueUpdates: []IssueUpdate{
-				{
-					Number:    1,
-					Labels:    []string{"forward/linked", "service/service1", "service/service2-subteam1"},
-					OldLabels: []string{"service/service2-subteam1", "forward/linked"},
-				},
-			},
+			regexpLabels:         defaultRegexpLabels,
+			expectedIssueUpdates: []IssueUpdate{},
 		},
 	}