cleanup, use changePosition

e2etest/submitter_e2e_test.go

@@ -4,7 +4,6 @@
 package e2etest
 
 import (
-	"github.com/babylonlabs-io/vigilante/submitter/relayer"
 	"math/rand"
 	"testing"
 	"time"
@@ -175,12 +174,7 @@ func TestSubmitterSubmissionReplace(t *testing.T) {
 	// 2. outputs with different values
 	// 3. different signatures
 	require.Equal(t, sendTransactions[1].MsgTx().TxIn[0].PreviousOutPoint, resendTx2.MsgTx().TxIn[0].PreviousOutPoint)
-
-	resendTxOutIdx, err := relayer.IndexOfChangeAddr(resendTx2.MsgTx().TxOut)
-	require.NoError(t, err)
-	ogTxOutIdx, err := relayer.IndexOfChangeAddr(sendTransactions[1].MsgTx().TxOut)
-	require.NoError(t, err)
-	require.Less(t, resendTx2.MsgTx().TxOut[resendTxOutIdx].Value, sendTransactions[1].MsgTx().TxOut[ogTxOutIdx].Value)
+	require.Less(t, resendTx2.MsgTx().TxOut[1].Value, sendTransactions[1].MsgTx().TxOut[1].Value)
 	require.NotEqual(t, sendTransactions[1].MsgTx().TxIn[0].Witness[0], resendTx2.MsgTx().TxIn[0].Witness[0])
 
 	// mine a block with those replacement transactions just to be sure they execute correctly

e2etest/test_manager.go

@@ -144,18 +144,14 @@ func StartManager(t *testing.T, numMatureOutputsInWallet uint32) *TestManager {
 		return true
 	}, eventuallyWaitTimeOut, eventuallyPollTime)
 
-	//walletPrivKey, err := testRpcClient.DumpPrivKey(minerAddressDecoded)
-	//require.NoError(t, err)
-
 	return &TestManager{
 		TestRpcClient:   testRpcClient,
 		BabylonHandler:  bh,
 		BabylonClient:   babylonClient,
 		BitcoindHandler: btcHandler,
 		BTCClient:       btcClient,
 		Config:          cfg,
-		//WalletPrivKey:   walletPrivKey.PrivKey,
-		WalletPrivKey: walletPrivKey,
+		WalletPrivKey:   walletPrivKey,
 	}
 }
 
@@ -245,14 +241,15 @@ func importPrivateKey(btcHandler *BitcoindTestHandler) (*btcec.PrivateKey, error
 		return nil, err
 	}
 
+	// "combo" allows us to import a key and handle multiple types of btc scripts with a single descriptor command.
 	descriptor := fmt.Sprintf("combo(%s)", wif.String())
 
 	// Create the JSON descriptor object.
 	descJSON, err := json.Marshal([]map[string]interface{}{
 		{
 			"desc":      descriptor,
 			"active":    true,
-			"timestamp": "now",
+			"timestamp": "now", // tells Bitcoind to start scanning from the current blockchain height
 			"label":     "test key",
 		},
 	})

submitter/relayer/relayer.go

@@ -175,12 +175,7 @@ func (rl *Relayer) resendSecondTxOfCheckpointToBTC(tx2 *types.BtcTxInfo, bumpedF
 		bumpedFee = balance
 	}
 
-	idx, err := IndexOfChangeAddr(tx2.Tx.TxOut)
-	if err != nil {
-		return nil, err
-	}
-
-	tx2.Tx.TxOut[idx].Value = int64(balance - bumpedFee)
+	tx2.Tx.TxOut[1].Value = int64(balance - bumpedFee)
 
 	// resign the tx as the output is changed
 	tx, err := rl.signTx(tx2.Tx)
@@ -273,7 +268,6 @@ func (rl *Relayer) convertCkptToTwoTxAndSubmit(ckpt *ckpttypes.RawCheckpointResp
 
 	// this is to wait for btcwallet to update utxo database so that
 	// the tx that tx1 consumes will not appear in the next unspent txs lit
-	// todo: Lazar chech if this needed?
 	time.Sleep(1 * time.Second)
 
 	rl.logger.Infof("Sent two txs to BTC for checkpointing epoch %v, first txid: %s, second txid: %s",
@@ -323,16 +317,11 @@ func (rl *Relayer) ChainTwoTxAndSend(
 		return nil, nil, fmt.Errorf("failed to send tx1 to BTC: %w", err)
 	}
 
-	changeIdx, err := IndexOfChangeAddr(tx1.Tx.TxOut)
-	if err != nil {
-		return nil, nil, err
-	}
-
 	changeUtxo := &types.UTXO{
 		TxID:     tx1.TxId,
 		Vout:     1,
-		ScriptPK: tx1.Tx.TxOut[changeIdx].PkScript,
-		Amount:   btcutil.Amount(tx1.Tx.TxOut[changeIdx].Value),
+		ScriptPK: tx1.Tx.TxOut[1].PkScript,
+		Amount:   btcutil.Amount(tx1.Tx.TxOut[1].Value),
 		Addr:     tx1.ChangeAddress,
 	}
 
@@ -395,21 +384,17 @@ func (rl *Relayer) buildTxWithData(
 	tx.AddTxOut(wire.NewTxOut(0, dataScript))
 
 	feeRate := btcutil.Amount(rl.getFeeRate()).ToBTC()
+	changePosition := 1
 	rawTxResult, err := rl.BTCWallet.FundRawTransaction(tx, btcjson.FundRawTransactionOpts{
-		FeeRate: &feeRate,
-		//EstimateMode: &btcjson.EstimateModeConservative,
+		FeeRate:        &feeRate,
+		ChangePosition: &changePosition,
 	}, nil)
 	if err != nil {
 		return nil, err
 	}
 
-	idxTxOut, err := IndexOfChangeAddr(rawTxResult.Transaction.TxOut)
-	if err != nil {
-		return nil, err
-	}
-
 	_, addresses, _, err := txscript.ExtractPkScriptAddrs(
-		rawTxResult.Transaction.TxOut[idxTxOut].PkScript,
+		rawTxResult.Transaction.TxOut[1].PkScript,
 		rl.GetNetParams(),
 	)
 

submitter/relayer/utils.go

@@ -2,8 +2,6 @@ package relayer
 
 import (
 	"bytes"
-	"errors"
-
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/mempool"
 	"github.com/btcsuite/btcd/wire"
@@ -22,20 +20,3 @@ func calculateTxVirtualSize(tx *wire.MsgTx) (int64, error) {
 
 	return mempool.GetTxVirtualSize(btcTx), nil
 }
-
-// IndexOfChangeAddr returns the index of the first transaction output with a non-zero value,
-// indicating a change address, or an error if none is found.
-func IndexOfChangeAddr(outs []*wire.TxOut) (uint, error) {
-	if outs == nil {
-		return 0, errors.New("nil outs param")
-	}
-
-	for index, out := range outs {
-		// A change address output must have a non-zero value.
-		if out.Value != 0 {
-			return uint(index), nil
-		}
-	}
-
-	return 0, errors.New("no TxOut with change addr found")
-}