Add channel to monitored transactor that returns error based on trans…

…action result

chains/evm/transactor/monitored/monitored.go

@@ -2,6 +2,7 @@ package monitored
 
 import (
 	"context"
+	"fmt"
 	"math/big"
 	"sync"
 	"time"
@@ -13,6 +14,7 @@ import (
 	"github.com/sygmaprotocol/sygma-core/chains/evm/client"
 	"github.com/sygmaprotocol/sygma-core/chains/evm/transactor"
 	"github.com/sygmaprotocol/sygma-core/chains/evm/transactor/transaction"
+	"github.com/sygmaprotocol/sygma-core/utils"
 )
 
 type GasPricer interface {
@@ -26,6 +28,7 @@ type RawTx struct {
 	gasLimit     uint64
 	gasPrice     []*big.Int
 	data         []byte
+	errChn       chan error
 	submitTime   time.Time
 	creationTime time.Time
 }
@@ -94,6 +97,7 @@ func (t *MonitoredTransactor) Transact(to *common.Address, data []byte, opts tra
 		gasLimit:     opts.GasLimit,
 		gasPrice:     gp,
 		data:         data,
+		errChn:       opts.ErrChn,
 		submitTime:   time.Now(),
 		creationTime: time.Now(),
 	}
@@ -145,8 +149,10 @@ func (t *MonitoredTransactor) Monitor(
 					if err == nil {
 						if receipt.Status == types.ReceiptStatusSuccessful {
 							log.Info().Uint64("nonce", tx.nonce).Msgf("Executed transaction %s with nonce %d", oldHash, tx.nonce)
+							utils.TrySendError(tx.errChn, nil)
 						} else {
 							log.Error().Uint64("nonce", tx.nonce).Msgf("Transaction %s failed on chain", oldHash)
+							utils.TrySendError(tx.errChn, fmt.Errorf("transaction %s failed on chain with nonce %d", oldHash, tx.nonce))
 						}
 
 						delete(t.pendingTxns, oldHash)
@@ -155,6 +161,7 @@ func (t *MonitoredTransactor) Monitor(
 
 					if time.Since(tx.creationTime) > txTimeout {
 						log.Error().Uint64("nonce", tx.nonce).Msgf("Transaction %s has timed out", oldHash)
+						utils.TrySendError(tx.errChn, fmt.Errorf("transaction %s has timed out", oldHash))
 						delete(t.pendingTxns, oldHash)
 						continue
 					}

chains/evm/transactor/monitored/monitored_test.go

@@ -106,6 +106,7 @@ func (s *TransactorTestSuite) TestTransactor_MonitoredTransaction_SuccessfulExec
 		big.NewInt(15))
 
 	go t.Monitor(ctx, time.Millisecond*50, time.Minute, time.Millisecond)
+	errChn := make(chan error, 1)
 	hash, err := t.Transact(
 		&common.Address{},
 		byteData,
@@ -119,6 +120,8 @@ func (s *TransactorTestSuite) TestTransactor_MonitoredTransaction_SuccessfulExec
 
 	time.Sleep(time.Millisecond * 150)
 	cancel()
+	err = <-errChn
+	s.Nil(err)
 }
 
 func (s *TransactorTestSuite) TestTransactor_MonitoredTransaction_TxTimeout() {
@@ -140,17 +143,22 @@ func (s *TransactorTestSuite) TestTransactor_MonitoredTransaction_TxTimeout() {
 		big.NewInt(1000),
 		big.NewInt(15))
 
+	errChn := make(chan error, 1)
 	go t.Monitor(ctx, time.Millisecond*50, time.Millisecond, time.Millisecond)
 	hash, err := t.Transact(
 		&common.Address{},
 		byteData,
-		transactor.TransactOptions{},
+		transactor.TransactOptions{
+			ErrChn: errChn,
+		},
 	)
 	s.mockClient.EXPECT().TransactionReceipt(gomock.Any(), *hash).Return(nil, fmt.Errorf("not found"))
 	s.Nil(err)
 
 	time.Sleep(time.Millisecond * 150)
 	cancel()
+	err = <-errChn
+	s.NotNil(err)
 }
 
 func (s *TransactorTestSuite) TestTransactor_MonitoredTransaction_TransactionResent() {

chains/evm/transactor/transact.go

@@ -21,6 +21,7 @@ type TransactOptions struct {
 	Nonce    *big.Int
 	ChainID  *big.Int
 	Priority uint8
+	ErrChn   chan error
 }
 
 // to save on data, we encode uin8 for transaction priority

utils/bytes.go

@@ -0,0 +1,7 @@
+package utils
+
+func SliceTo32Bytes(in []byte) [32]byte {
+	var res [32]byte
+	copy(res[:], in)
+	return res
+}

utils/channel.go

@@ -0,0 +1,12 @@
+package utils
+
+// TrySendError attempts to send error over the given channel.
+// It prevents blocking when a channel is busy or nil.
+func TrySendError(errChn chan error, err error) bool {
+	select {
+	case errChn <- err:
+		return true
+	default:
+		return false
+	}
+}