lndclient: handle CloseInstant update

Author: hieblmi

lightning_client.go

@@ -3138,13 +3138,23 @@ func (p *PendingCloseUpdate) CloseTxid() chainhash.Hash {
 type ChannelClosedUpdate struct {
 	// CloseTx is the closing transaction id.
 	CloseTx chainhash.Hash
+
+	// NumPendingHtlcs is the number of pending htlcs that we have
+	// present while a channel close with the NoWait option was in progress.
+	NumPendingHtlcs int32
 }
 
 // CloseTxid returns the closing txid of the channel.
 func (p *ChannelClosedUpdate) CloseTxid() chainhash.Hash {
 	return p.CloseTx
 }
 
+// NumberOfPendingHtlcs returns the number of pending htlcs that we have
+// present while a channel close with NoWait option was in progress.
+func (p *ChannelClosedUpdate) NumberOfPendingHtlcs() int32 {
+	return p.NumPendingHtlcs
+}
+
 // CloseChannelOption is a functional type for an option that modifies a
 // CloseChannelRequest.
 type CloseChannelOption func(r *lnrpc.CloseChannelRequest)
@@ -3291,6 +3301,21 @@ func (s *lightningClient) CloseChannel(ctx context.Context,
 				}
 				sendUpdate(closeUpdate)
 
+			case *lnrpc.CloseStatusUpdate_CloseInstant:
+				instantUpdate := update.CloseInstant
+				if instantUpdate == nil {
+					sendErr(errors.New("instant update " +
+						"unavailable"))
+
+					return
+				}
+
+				numPendingHtlcs := instantUpdate.NumPendingHtlcs
+				closeUpdate := &ChannelClosedUpdate{
+					NumPendingHtlcs: numPendingHtlcs,
+				}
+				sendUpdate(closeUpdate)
+
 			default:
 				sendErr(fmt.Errorf("unknown channel close "+
 					"update: %T", resp.Update))