EVM Transaction handler and contract creation (#96)

* WIP implementing state transition function

* Error handling and application setup fix

* Fixed error comment

* Allow creation of state objects with a BaseAccount

* Fixed parameters and finalise state after transaction

* updated transaction signing and cli signature

* Set up consistent account encoding and decoding

* Update txbuilder to get sequence before generating eth tx

* Added create functionality to the CLI command

* Remove need to copy over context for statedb interactions

* Updated account retriever

* Cleaned up handler code and updated TODO

* Make recoverEthSig private again

* Add error check for committing to kv store

* Remove commented out code

* Update evm chain config for state transition

* Add time in context for dapps

x/evm/client/cli/tx.go

@@ -88,9 +88,9 @@ func GetCmdGenTx(cdc *codec.Codec) *cobra.Command {
 // GetCmdGenTx generates an ethereum transaction
 func GetCmdGenETHTx(cdc *codec.Codec) *cobra.Command {
 	return &cobra.Command{
-		Use:   "generate-eth-tx [nonce] [ethaddress] [amount] [gaslimit] [gasprice] [payload]",
-		Short: "geberate and broadcast an Ethereum tx",
-		Args:  cobra.ExactArgs(6),
+		Use:   "generate-eth-tx [amount] [gaslimit] [gasprice] [payload] [<ethereum-address>]",
+		Short: "generate and broadcast an Ethereum tx. If address is not specified, contract will be created",
+		Args:  cobra.RangeArgs(4, 5),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			cliCtx := emintUtils.NewETHCLIContext().WithCodec(cdc)
 
@@ -101,35 +101,41 @@ func GetCmdGenETHTx(cdc *codec.Codec) *cobra.Command {
 				panic(err)
 			}
 
-			nonce, err := strconv.ParseUint(args[0], 0, 64)
+			coins, err := sdk.ParseCoins(args[0])
 			if err != nil {
 				return err
 			}
 
-			coins, err := sdk.ParseCoins(args[2])
+			gasLimit, err := strconv.ParseUint(args[1], 0, 64)
 			if err != nil {
 				return err
 			}
 
-			gasLimit, err := strconv.ParseUint(args[3], 0, 64)
+			gasPrice, err := strconv.ParseUint(args[2], 0, 64)
 			if err != nil {
 				return err
 			}
 
-			gasPrice, err := strconv.ParseUint(args[4], 0, 64)
+			payload := args[3]
+
+			txBldr, err = emintUtils.PrepareTxBuilder(txBldr, cliCtx)
 			if err != nil {
 				return err
 			}
 
-			payload := args[5]
+			var tx *types.EthereumTxMsg
+			if len(args) == 5 {
+				tx = types.NewEthereumTxMsg(txBldr.Sequence(), ethcmn.HexToAddress(args[4]), big.NewInt(coins.AmountOf(emintTypes.DenomDefault).Int64()), gasLimit, new(big.Int).SetUint64(gasPrice), []byte(payload))
+			} else {
+				tx = types.NewEthereumTxMsgContract(txBldr.Sequence(), big.NewInt(coins.AmountOf(emintTypes.DenomDefault).Int64()), gasLimit, new(big.Int).SetUint64(gasPrice), []byte(payload))
+			}
 
-			tx := types.NewEthereumTxMsg(nonce, ethcmn.HexToAddress(args[1]), big.NewInt(coins.AmountOf(emintTypes.DenomDefault).Int64()), gasLimit, new(big.Int).SetUint64(gasPrice), []byte(payload))
 			err = tx.ValidateBasic()
 			if err != nil {
 				return err
 			}
 
-			return emintUtils.BroadcastETHTx(cliCtx, txBldr.WithSequence(nonce).WithKeybase(kb), tx)
+			return emintUtils.BroadcastETHTx(cliCtx, txBldr.WithKeybase(kb), tx)
 		},
 	}
 }

x/evm/client/utils/tx.go

@@ -42,10 +42,6 @@ func GenerateOrBroadcastETHMsgs(cliCtx context.CLIContext, txBldr authtypes.TxBu
 
 // BroadcastETHTx Broadcasts an Ethereum Tx not wrapped in a Std Tx
 func BroadcastETHTx(cliCtx context.CLIContext, txBldr authtypes.TxBuilder, tx *evmtypes.EthereumTxMsg) error {
-	txBldr, err := utils.PrepareTxBuilder(txBldr, cliCtx)
-	if err != nil {
-		return err
-	}
 
 	fromName := cliCtx.GetFromName()
 
@@ -346,3 +342,34 @@ func getFromFields(from string, genOnly bool) (sdk.AccAddress, string, error) {
 
 	return info.GetAddress(), info.GetName(), nil
 }
+
+// * Overriden function from cosmos-sdk/auth/client/utils/tx.go
+// PrepareTxBuilder populates a TxBuilder in preparation for the build of a Tx.
+func PrepareTxBuilder(txBldr authtypes.TxBuilder, cliCtx context.CLIContext) (authtypes.TxBuilder, error) {
+	from := cliCtx.GetFromAddress()
+
+	// * Function is needed to override to use different account getter (to not use static codec)
+	accGetter := emint.NewAccountRetriever(cliCtx, cliCtx.Codec)
+	if err := accGetter.EnsureExists(from); err != nil {
+		return txBldr, err
+	}
+
+	txbldrAccNum, txbldrAccSeq := txBldr.AccountNumber(), txBldr.Sequence()
+	// TODO: (ref #1903) Allow for user supplied account number without
+	// automatically doing a manual lookup.
+	if txbldrAccNum == 0 || txbldrAccSeq == 0 {
+		num, seq, err := accGetter.GetAccountNumberSequence(from)
+		if err != nil {
+			return txBldr, err
+		}
+
+		if txbldrAccNum == 0 {
+			txBldr = txBldr.WithAccountNumber(num)
+		}
+		if txbldrAccSeq == 0 {
+			txBldr = txBldr.WithSequence(seq)
+		}
+	}
+
+	return txBldr, nil
+}