format code

db.go

@@ -129,14 +129,22 @@ func Open(options Options) (*DB, error) {
 		go db.watcher.sendEvent(db.watchCh)
 	}
 
+	// enable auto merge task
 	if len(options.AutoMergeCronExpr) > 0 {
-		db.cronScheduler = cron.New(cron.WithParser(
-			cron.NewParser(cron.SecondOptional | cron.Minute | cron.Hour | cron.Dom | cron.Month | cron.Dow | cron.Descriptor)))
-		db.cronScheduler.AddFunc(options.AutoMergeCronExpr, func() {
+		db.cronScheduler = cron.New(
+			cron.WithParser(
+				cron.NewParser(cron.SecondOptional | cron.Minute | cron.Hour |
+					cron.Dom | cron.Month | cron.Dow | cron.Descriptor),
+			),
+		)
+		_, err = db.cronScheduler.AddFunc(options.AutoMergeCronExpr, func() {
 			// maybe we should deal with different errors with different logic, but a background task can't omit its error.
 			// after auto merge, we should close and reopen the db.
 			_ = db.Merge(true)
 		})
+		if err != nil {
+			return nil, err
+		}
 		db.cronScheduler.Start()
 	}