Add-guard-against-deposit-transaction (#211)

adapters.go

@@ -111,7 +111,7 @@ func AdaptCosmosTxsToEthTxs(cosmosTxs bfttypes.Txs) (ethtypes.Transactions, erro
 		return ethtypes.Transactions{}, nil
 	}
 	txsBytes := cosmosTxs.ToSliceOfBytes()
-	ethTxs, err := getDepositTxs(txsBytes)
+	ethTxs, err := GetDepositTxs(txsBytes)
 	if err != nil {
 		return nil, fmt.Errorf("get deposit txs: %v", err)
 	}
@@ -122,7 +122,7 @@ func AdaptCosmosTxsToEthTxs(cosmosTxs bfttypes.Txs) (ethtypes.Transactions, erro
 	return ethTxs, nil
 }
 
-func getDepositTxs(txsBytes [][]byte) (ethtypes.Transactions, error) {
+func GetDepositTxs(txsBytes [][]byte) (ethtypes.Transactions, error) {
 	cosmosEthTx := new(sdktx.Tx)
 	if err := cosmosEthTx.Unmarshal(txsBytes[0]); err != nil {
 		return nil, fmt.Errorf("unmarshal cosmos tx: %v", err)

mempool/mempool.go

@@ -8,6 +8,7 @@ import (
 
 	comettypes "github.com/cometbft/cometbft/types"
 	dbm "github.com/cosmos/cosmos-db"
+	"github.com/polymerdao/monomer"
 	"github.com/polymerdao/monomer/utils"
 )
 
@@ -38,6 +39,13 @@ func (p *Pool) Enqueue(userTxn comettypes.Tx) (err error) {
 	// Unfortunately, comet's DB interface doesn't support it.
 	// Moving to a different DB interface is left for future work.
 
+	// Attempt to adapt the Cosmos transaction to an Ethereum deposit transaction.
+	// If the adaptation succeeds, it indicates that the
+	// user transaction is a deposit transaction, which is not allowed in the pool.
+	if _, err := monomer.GetDepositTxs([][]byte{userTxn}); err == nil {
+		return errors.New("deposit txs are not allowed in the pool")
+	}
+
 	batch := p.db.NewBatch()
 	defer func() {
 		err = utils.WrapCloseErr(err, batch)

mempool/mempool_test.go

@@ -4,6 +4,8 @@ import (
 	"testing"
 
 	comettypes "github.com/cometbft/cometbft/types"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/polymerdao/monomer"
 	"github.com/polymerdao/monomer/mempool"
 	"github.com/polymerdao/monomer/testutils"
 	"github.com/stretchr/testify/assert"
@@ -22,6 +24,16 @@ func TestMempool(t *testing.T) {
 		require.Error(t, err)
 	})
 
+	t.Run("deposit transaction", func(t *testing.T) {
+		_, depositTx, _ := testutils.GenerateEthTxs(t)
+		depositTxBytes, err := depositTx.MarshalBinary()
+		require.NoError(t, err)
+
+		cosmosTxs, err := monomer.AdaptPayloadTxsToCosmosTxs([]hexutil.Bytes{depositTxBytes}, nil, "")
+		require.NoError(t, err)
+		require.ErrorContains(t, pool.Enqueue(cosmosTxs[0]), "deposit txs are not allowed in the pool")
+	})
+
 	// enqueue multiple to empty
 	for i := byte(0); i < 3; i++ {
 		require.NoError(t, pool.Enqueue(comettypes.Tx([]byte{i})))