Merge pull request #6 from bcdevtools/imp/allow-send-erc20

imp: allow send ERC-20

Author: 0xbcdev

cmd/tx/send.go

@@ -7,28 +7,57 @@ import (
 	"fmt"
 	"math/big"
 
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+
 	"github.com/bcdevtools/devd/v2/cmd/utils"
 	ethtypes "github.com/ethereum/go-ethereum/core/types"
 	"github.com/spf13/cobra"
 )
 
+const flagErc20 = "erc20"
+
 func GetSendEvmTxCommand() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "send [to] [amount]",
-		Short: "Send some token to an address via EVM transfer",
+		Short: "Send some native coin or ERC-20 token to an address",
 		Args:  cobra.ExactArgs(2),
 		Run: func(cmd *cobra.Command, args []string) {
 			ethClient8545, _ := mustGetEthClient(cmd)
 
 			evmAddrs, err := utils.GetEvmAddressFromAnyFormatAddress(args[0])
 			utils.ExitOnErr(err, "failed to get evm address from input")
 
+			var pErc20ContractAddress *common.Address
+			erc20ContractAddress, _ := cmd.Flags().GetString(flagErc20)
+			if erc20ContractAddress != "" {
+				if !common.IsHexAddress(erc20ContractAddress) {
+					utils.ExitOnErr(fmt.Errorf("invalid format"), "failed to parse ERC-20 contract address")
+				}
+				contractAddr := common.HexToAddress(erc20ContractAddress)
+				pErc20ContractAddress = &contractAddr
+			}
+
 			receiverAddr := evmAddrs[0]
 			amount, ok := new(big.Int).SetString(args[1], 10)
 			if !ok {
 				utils.ExitOnErr(fmt.Errorf("invalid amount %s", args[1]), "failed to parse amount")
 			}
-			display, _, _, err := utils.ConvertNumberIntoDisplayWithExponent(amount, 18)
+
+			var exponent int
+			if pErc20ContractAddress != nil {
+				bz, err := ethClient8545.CallContract(context.Background(), ethereum.CallMsg{
+					To:   pErc20ContractAddress,
+					Data: []byte{0x31, 0x3c, 0xe5, 0x67}, // decimals()
+				}, nil)
+				utils.ExitOnErr(err, "failed to get contract decimals")
+
+				contractDecimals := new(big.Int).SetBytes(bz)
+				exponent = int(contractDecimals.Int64())
+			} else {
+				exponent = 18
+			}
+			display, _, _, err := utils.ConvertNumberIntoDisplayWithExponent(amount, exponent)
 			utils.ExitOnErr(err, "failed to convert amount into display with exponent")
 
 			_, ecdsaPrivateKey, _, from := mustSecretEvmAccount(cmd)
@@ -39,12 +68,28 @@ func GetSendEvmTxCommand() *cobra.Command {
 			chainId, err := ethClient8545.ChainID(context.Background())
 			utils.ExitOnErr(err, "failed to get chain ID")
 
-			txData := ethtypes.LegacyTx{
-				Nonce:    nonce,
-				GasPrice: big.NewInt(20_000_000_000),
-				Gas:      21000,
-				To:       &receiverAddr,
-				Value:    amount,
+			var txData ethtypes.LegacyTx
+			if pErc20ContractAddress != nil {
+				data := []byte{0xa9, 0x05, 0x9c, 0xbb}
+				data = append(data, common.LeftPadBytes(receiverAddr.Bytes(), 32)...)
+				data = append(data, common.LeftPadBytes(amount.Bytes(), 32)...)
+
+				txData = ethtypes.LegacyTx{
+					Nonce:    nonce,
+					GasPrice: big.NewInt(20_000_000_000),
+					Gas:      500_000,
+					To:       pErc20ContractAddress,
+					Value:    big.NewInt(0),
+					Data:     data,
+				}
+			} else {
+				txData = ethtypes.LegacyTx{
+					Nonce:    nonce,
+					GasPrice: big.NewInt(20_000_000_000),
+					Gas:      21000,
+					To:       &receiverAddr,
+					Value:    amount,
+				}
 			}
 			tx := ethtypes.NewTx(&txData)
 
@@ -68,6 +113,7 @@ func GetSendEvmTxCommand() *cobra.Command {
 
 	cmd.Flags().String(flagRpc, "", flagEvmRpcDesc)
 	cmd.Flags().String(flagSecretKey, "", flagSecretKeyDesc)
+	cmd.Flags().String(flagErc20, "", "contract address if you want to send ERC-20 token instead of native coin")
 
 	return cmd
 }