rpc: fix nil pointer exception when parameters are nil (#180)

* fix nil pointer exception when parameters are nil

* Update ethereum/rpc/types/types.go

Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>

ethereum/rpc/namespaces/eth/api.go

@@ -347,7 +347,7 @@ func (e *PublicAPI) Sign(address common.Address, data hexutil.Bytes) (hexutil.By
 
 // SendTransaction sends an Ethereum transaction.
 func (e *PublicAPI) SendTransaction(args rpctypes.SendTxArgs) (common.Hash, error) {
-	e.logger.Debugln("eth_sendTransaction", "args", args)
+	e.logger.Debugln("eth_sendTransaction", "args", args.String())
 
 	// Look up the wallet containing the requested signer
 	_, err := e.clientCtx.Keyring.KeyByAddress(sdk.AccAddress(args.From.Bytes()))
@@ -493,7 +493,7 @@ func (e *PublicAPI) SendRawTransaction(data hexutil.Bytes) (common.Hash, error)
 
 // Call performs a raw contract call.
 func (e *PublicAPI) Call(args rpctypes.CallArgs, blockNr rpctypes.BlockNumber, _ *rpctypes.StateOverride) (hexutil.Bytes, error) {
-	e.logger.Debugln("eth_call", "args", args, "block number", blockNr)
+	e.logger.Debugln("eth_call", "args", args.String(), "block number", blockNr)
 	simRes, err := e.doCall(args, blockNr, big.NewInt(ethermint.DefaultRPCGasLimit))
 	if err != nil {
 		return []byte{}, err

ethereum/rpc/types/types.go

@@ -1,6 +1,8 @@
 package types
 
 import (
+	"fmt"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	ethtypes "github.com/ethereum/go-ethereum/core/types"
@@ -68,6 +70,20 @@ type SendTxArgs struct {
 	ChainID    *hexutil.Big         `json:"chainId,omitempty"`
 }
 
+// String return the struct in a string format
+func (args *SendTxArgs) String() string {
+	// Todo: There is currently a bug with hexutil.Big when the value its nil, printing would trigger an exception
+	return fmt.Sprintf("SendTxArgs{From:%v, To:%v, Gas:%v,"+
+		" Nonce:%v, Data:%v, Input:%v, AccessList:%v}",
+		args.From,
+		args.To,
+		args.Gas,
+		args.Nonce,
+		args.Data,
+		args.Input,
+		args.AccessList)
+}
+
 // ToTransaction converts the arguments to an ethereum transaction.
 // This assumes that setTxDefaults has been called.
 func (args *SendTxArgs) ToTransaction() *evmtypes.MsgEthereumTx {
@@ -79,16 +95,34 @@ func (args *SendTxArgs) ToTransaction() *evmtypes.MsgEthereumTx {
 	}
 
 	data := &evmtypes.TxData{
-		To:       args.To.Hex(),
-		ChainID:  args.ChainID.ToInt().Bytes(),
-		Nonce:    uint64(*args.Nonce),
-		GasLimit: uint64(*args.Gas),
-		GasPrice: args.GasPrice.ToInt().Bytes(),
-		Amount:   args.Value.ToInt().Bytes(),
 		Input:    input,
 		Accesses: evmtypes.NewAccessList(args.AccessList),
 	}
 
+	if args.ChainID != nil {
+		data.ChainID = args.ChainID.ToInt().Bytes()
+	}
+
+	if args.Nonce != nil {
+		data.Nonce = uint64(*args.Nonce)
+	}
+
+	if args.Gas != nil {
+		data.GasLimit = uint64(*args.Gas)
+	}
+
+	if args.GasPrice != nil {
+		data.GasPrice = args.GasPrice.ToInt().Bytes()
+	}
+
+	if args.Value != nil {
+		data.Amount = args.Value.ToInt().Bytes()
+	}
+
+	if args.To != nil {
+		data.To = args.To.Hex()
+	}
+
 	return &evmtypes.MsgEthereumTx{
 		Data: data,
 		From: args.From.String(),
@@ -106,6 +140,18 @@ type CallArgs struct {
 	AccessList *ethtypes.AccessList `json:"accessList"`
 }
 
+// String return the struct in a string format
+func (args *CallArgs) String() string {
+	// Todo: There is currently a bug with hexutil.Big when the value its nil, printing would trigger an exception
+	return fmt.Sprintf("SendTxArgs{From:%v, To:%v, Gas:%v,"+
+		" Data:%v, AccessList:%v}",
+		args.From,
+		args.To,
+		args.Gas,
+		args.Data,
+		args.AccessList)
+}
+
 // StateOverride is the collection of overridden accounts.
 type StateOverride map[common.Address]OverrideAccount