Fix block hex parse to number

internal/adapters/execution/execution_adapter.go

@@ -2,9 +2,12 @@ package execution
 
 import (
 	"bytes"
+	"encoding/binary"
 	"encoding/json"
 	"fmt"
 	"net/http"
+
+	"github.com/ethereum/go-ethereum/common/hexutil"
 )
 
 // ExecutionAdapter interacts with the Ethereum execution client to fetch block information.
@@ -54,13 +57,24 @@ func (e *ExecutionAdapter) GetMostRecentBlockNumber() (uint64, error) {
 		return 0, fmt.Errorf("failed to decode response from execution client: %w", err)
 	}
 
-	// Convert the hexadecimal block number to uint64
-	var blockNumber uint64
-	_, err = fmt.Sscanf(result.Result, "0x%x", &blockNumber)
+	// Convert the hexadecimal block number to uint64 using hexutil.Decode
+	decodedBytes, err := hexutil.Decode(result.Result)
 	if err != nil {
-		return 0, fmt.Errorf("failed to parse block number from result %s: %w", result.Result, err)
+		return 0, fmt.Errorf("failed to decode block number from result %s: %w", result.Result, err)
+	}
+
+	// Ensure the decoded byte slice does not exceed 8 bytes for uint64
+	if len(decodedBytes) > 8 {
+		return 0, fmt.Errorf("block number too large to fit in uint64: length %d bytes", len(decodedBytes))
 	}
 
+	// Convert the byte slice to uint64
+	var blockNumber uint64
+	// If the byte slice is less than 8 bytes, pad it with leading zeros
+	paddedBytes := make([]byte, 8)
+	copy(paddedBytes[8-len(decodedBytes):], decodedBytes)
+	blockNumber = binary.BigEndian.Uint64(paddedBytes)
+
 	return blockNumber, nil
 }