fix: accept verified no-op auto-match lease renewals (#359)

server/app/goauto/shopeeproduct/auto_match_batch.go

@@ -380,7 +380,14 @@ func (service *Service) renewAutoMatchRun(ctx context.Context, run models.Shopee
 		if err := lockAutoMatchRun(ctx, tx, run); err != nil {
 			return err
 		}
-		return autoMatchOwnedUpdate(autoMatchOwnedRun(tx, run).Update("lease_expires_at", time.Now().UTC().Add(autoMatchLeaseDuration)))
+		result := autoMatchOwnedRun(tx, run).Update("lease_expires_at", time.Now().UTC().Add(autoMatchLeaseDuration))
+		if result.Error == nil && result.RowsAffected == 0 {
+			// MySQL's changed-row count can be zero when datetime precision
+			// rounds a rapid renewal to the stored value. Under the same row
+			// lock, distinguish that no-op from an expired or lost lease.
+			return lockAutoMatchRun(ctx, tx, run)
+		}
+		return autoMatchOwnedUpdate(result)
 	})
 }
 

server/app/goauto/shopeeproduct/auto_match_scan_test.go

@@ -739,3 +739,46 @@ func TestAutoMatchDeadlineDuringCheckpointReadCannotCommitFalseHead(t *testing.T
 		t.Fatalf("unknown cursor committed: %+v", latest)
 	}
 }
+
+func TestAutoMatchRenewZeroChangedRowsRequiresLiveOwnership(t *testing.T) {
+	for _, change := range []string{"unchanged", "expired", "owner", "multiple_rows"} {
+		t.Run(change, func(t *testing.T) {
+			db := openScanTestDB(t)
+			s := NewService(db)
+			run, _, err := s.StartAutoMatchRun(context.Background(), "manual", uuid.NewString(), nil, 20)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if err := db.Callback().Update().After("gorm:update").Register("test_renew_zero_changed", func(tx *gorm.DB) {
+				if tx.Statement.Table != "shopee_spec_auto_match_run" || tx.Error != nil {
+					return
+				}
+				// MySQL reports changed rows by default: datetime(3) may round a
+				// same-millisecond renewal to the value already stored.
+				switch change {
+				case "expired":
+					err = tx.Session(&gorm.Session{NewDB: true}).Exec("UPDATE shopee_spec_auto_match_run SET lease_expires_at = ? WHERE id = ?", time.Now().UTC().Add(-time.Second), run.ID).Error
+				case "owner":
+					err = tx.Session(&gorm.Session{NewDB: true}).Exec("UPDATE shopee_spec_auto_match_run SET lease_owner = ? WHERE id = ?", "replacement-owner", run.ID).Error
+				}
+				if err != nil {
+					tx.AddError(err)
+				}
+				tx.RowsAffected = 0
+				if change == "multiple_rows" {
+					tx.RowsAffected = 2
+				}
+			}); err != nil {
+				t.Fatal(err)
+			}
+			err = s.renewAutoMatchRun(context.Background(), run.ShopeeSpecAutoMatchRun)
+			if change == "unchanged" {
+				if err != nil {
+					t.Fatalf("live no-op renewal rejected: %v", err)
+				}
+			} else if err != errAutoMatchLeaseLost {
+				t.Fatalf("lost lease accepted after zero changed rows: %v", err)
+			}
+		})
+	}
+}