Skip transaction if no signatures found

bridge/docs/observability.md

@@ -59,6 +59,7 @@ For example, if a customer is complaining that their deposit never bridged, you
 - `event_refund_tx_expired_received`: The bridge instance has received TFChain  `RefundTransactionExpired` event.
 - `refund_skipped`: a refund request skipped by the bridge instance as it has already been refunded.
 - `refund_proposed`: a refund has proposed or signed by the bridge instance.
+- `refund_postponed`: a refund has postponed due to a problem in sending this transaction to the stellar network and will be retried later.
 - `refund_completed`: a refund has completed and received on the target stellar account.
 
 ##### Withdraw related 

bridge/tfchain_bridge/pkg/bridge/refund.go

@@ -89,6 +89,15 @@ func (bridge *Bridge) handleRefundReady(ctx context.Context, refundReadyEvent su
 		return err
 	}
 
+	if len(refund.Signatures) == 0 {
+		logger.Info().
+			Str("event_action", "refund_postponed").
+			Str("event_kind", "event").
+			Str("category", "refund").
+			Msg("the refund has been postponed due to the transaction signatures being removed on the TFChain side while the bridge was processing the transaction")
+		return nil
+	}
+
 	// Todo, retry here?
 	if err = bridge.wallet.CreateRefundPaymentWithSignaturesAndSubmit(ctx, refund.Target, uint64(refund.Amount), refund.TxHash, refund.Signatures, int64(refund.SequenceNumber)); err != nil {
 		return err

bridge/tfchain_bridge/pkg/bridge/withdraw.go

@@ -149,7 +149,12 @@ func (bridge *Bridge) handleWithdrawReady(ctx context.Context, withdrawReady sub
 	}
 
 	if len(burnTx.Signatures) == 0 {
-		return pkg.ErrNoSignatures
+		logger.Info().
+			Str("event_action", "withdraw_postponed").
+			Str("event_kind", "event").
+			Str("category", "withdraw").
+			Msg("the withdraw has been postponed due to the transaction signatures being removed on the TFChain side while the bridge was processing the transaction")
+		return nil
 	}
 
 	// todo add memo hash