allow fee denom countract not found (#40)

x/evm/keeper/context.go

@@ -3,9 +3,11 @@ package keeper
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"math"
 	"math/big"
 
+	"cosmossdk.io/collections"
 	"github.com/holiman/uint256"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -45,17 +47,14 @@ func (k Keeper) buildBlockContext(ctx context.Context, evm callableEVM) (vm.Bloc
 		headerHash = make([]byte, 32)
 	}
 
-	var contractAddr common.Address
-	if !k.initializing {
-		params, err := k.Params.Get(ctx)
-		if err != nil {
-			return vm.BlockContext{}, err
-		}
+	params, err := k.Params.Get(ctx)
+	if err != nil {
+		return vm.BlockContext{}, err
+	}
 
-		contractAddr, err = types.DenomToContractAddr(ctx, k, params.FeeDenom)
-		if err != nil {
-			return vm.BlockContext{}, err
-		}
+	contractAddr, err := types.DenomToContractAddr(ctx, k, params.FeeDenom)
+	if err != nil && !errors.Is(err, collections.ErrNotFound) {
+		return vm.BlockContext{}, err
 	}
 
 	// TODO: should we charge gas for CanTransfer and Transfer?
@@ -72,6 +71,11 @@ func (k Keeper) buildBlockContext(ctx context.Context, evm callableEVM) (vm.Bloc
 				return true
 			}
 
+			// if the contract is not found, return false
+			if (contractAddr == common.Address{}) {
+				return false
+			}
+
 			inputBz, err := k.erc20Keeper.GetERC20ABI().Pack("balanceOf", a)
 			if err != nil {
 				return false

x/evm/keeper/erc20.go

@@ -2,6 +2,7 @@ package keeper
 
 import (
 	"context"
+	"errors"
 	"math/big"
 	"strings"
 
@@ -99,7 +100,9 @@ func (k ERC20Keeper) GetBalance(ctx context.Context, addr sdk.AccAddress, denom
 	}
 
 	contractAddr, err := types.DenomToContractAddr(ctx, k, denom)
-	if err != nil {
+	if err != nil && errors.Is(err, collections.ErrNotFound) {
+		return math.ZeroInt(), nil
+	} else if err != nil {
 		return math.ZeroInt(), err
 	}
 
@@ -225,7 +228,9 @@ func (k ERC20Keeper) GetSupply(ctx context.Context, denom string) (math.Int, err
 // HasSupply implements IERC20Keeper.
 func (k ERC20Keeper) HasSupply(ctx context.Context, denom string) (bool, error) {
 	contractAddr, err := types.DenomToContractAddr(ctx, k, denom)
-	if err != nil {
+	if err != nil && errors.Is(err, collections.ErrNotFound) {
+		return false, nil
+	} else if err != nil {
 		return false, err
 	}
 

x/evm/keeper/genesis.go

@@ -15,18 +15,12 @@ import (
 )
 
 func (k Keeper) Initialize(ctx context.Context) error {
+	// 1. deploy erc20 factory contract
 	code, err := hexutil.Decode(erc20_factory.Erc20FactoryBin)
 	if err != nil {
 		return err
 	}
 
-	// This is temporal alive flag to prevent checking fee denom erc20 coin existence
-	// during this function execution. It will be reverted to false after the erc20
-	// fee denom contract is deployed.
-	//
-	//
-	// This function is not pointer receiver, so it will not affect the original value.
-	k.initializing = true
 	_, _, _, err = k.EVMCreate2(ctx, types.StdAddress, code, nil, types.ERC20FactorySalt)
 	if err != nil {
 		return err
@@ -37,13 +31,12 @@ func (k Keeper) Initialize(ctx context.Context) error {
 		return err
 	}
 
-	// deploy fee denom erc20 coins at genesis bootstrapping
+	// 2. deploy fee denom erc20 coins at genesis bootstrapping
 	err = k.erc20Keeper.CreateERC20(ctx, params.FeeDenom)
 	if err != nil {
 		return err
 	}
 
-	// k.initialize will be reverted to false.
 	return nil
 }
 

x/evm/keeper/keeper.go

@@ -56,9 +56,6 @@ type Keeper struct {
 
 	precompiles          precompiles
 	queryCosmosWhitelist types.QueryCosmosWhitelist
-
-	// flag to check if the keeper is in the process of initialization
-	initializing bool
 }
 
 func NewKeeper(