Add tool to reconstruct L2 deposit tx hash (#12893)

op-chain-ops/cmd/deposit-hash/main.go

+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+
+	"github.com/ethereum-optimism/optimism/op-node/rollup/derive"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+func main() {
+	var rpcURL, txHash string
+	flag.StringVar(&rpcURL, "rpc", "", "L1 RPC URL")
+	flag.StringVar(&txHash, "tx", "", "Deposit transaction hash on L1")
+	flag.Parse()
+
+	depositLogTopic := common.HexToHash("0xb3813568d9991fc951961fcb4c784893574240a28925604d09fc577c55bb7c32")
+
+	ethClient, err := ethclient.Dial(rpcURL)
+	if err != nil {
+		log.Crit("Error creating RPC", "err", err)
+	}
+
+	l1Receipt, err := ethClient.TransactionReceipt(context.TODO(), common.HexToHash(txHash))
+	if err != nil {
+		log.Crit("Error fetching transaction", "err", err)
+	}
+
+	for _, ethLog := range l1Receipt.Logs {
+		if ethLog.Topics[0].String() == depositLogTopic.String() {
+
+			reconstructedDep, err := derive.UnmarshalDepositLogEvent(ethLog)
+			if err != nil {
+				log.Crit("Failed to parse deposit event ", "err", err)
+			}
+			tx := types.NewTx(reconstructedDep)
+			fmt.Println("L2 Tx Hash", tx.Hash().String())
+		}
+	}
+}