evmos · fedekunze · Sep 30, 2024 · Sep 30, 2024 · Sep 30, 2024
@@ -64,6 +64,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 - (evm) [#2872](https://github.com/evmos/evmos/pull/2872) Change `BankKeeper` for `BankWrapper` to manage EVM coin with different decimals.
 - (evm) [#2873](https://github.com/evmos/evmos/pull/2873) Remove `BeginBlock` and replace `ChainID` with global config.
 - (api) [#2884](https://github.com/evmos/evmos/pull/2884) Refactor to use a function to return `TxDataV2` in custom `GetSingers`.
+- (evm) [#2897](https://github.com/evmos/evmos/pull/2897) Adjust extra decimals in `AddBalance` and `SubBalance` methods on `stateObject` in state DB.
 
 ## [v19.2.1](https://github.com/evmos/evmos/releases/tag/v19.2.1) - 2024-09-27
 

@@ -11,6 +11,7 @@ import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/evmos/evmos/v20/x/evm/types"
+	"github.com/evmos/evmos/v20/x/evm/wrappers"
 )
 
 // Account is the Ethereum consensus representation of accounts.
@@ -100,6 +101,7 @@ func (s *stateObject) markSuicided() {
 // AddBalance adds amount to s's balance.
 // It is used to add funds to the destination account of a transfer.
 func (s *stateObject) AddBalance(amount *big.Int) {
+	amount = wrappers.AdjustExtraDecimalsBigInt(amount)
 	if amount.Sign() == 0 {
 		return
 	}
@@ -109,6 +111,7 @@ func (s *stateObject) AddBalance(amount *big.Int) {
 // SubBalance removes amount from s's balance.
 // It is used to remove funds from the origin account of a transfer.
 func (s *stateObject) SubBalance(amount *big.Int) {
+	amount = wrappers.AdjustExtraDecimalsBigInt(amount)
 	if amount.Sign() == 0 {
 		return
 	}

@@ -42,7 +42,7 @@ func NewBankWrapper(
 func (w BankWrapper) MintAmountToAccount(ctx context.Context, recipientAddr sdk.AccAddress, amt *big.Int) error {
 	coin := sdk.Coin{Denom: config.GetEVMCoinDenom(), Amount: sdkmath.NewIntFromBigInt(amt)}
 
-	convertedCoin, err := convertEvmCoinFrom18Decimals(coin)
+	convertedCoin, err := ConvertEvmCoinFrom18Decimals(coin)
 	if err != nil {
 		return errors.Wrap(err, "failed to mint coin to account in bank wrapper")
 	}
@@ -60,7 +60,7 @@ func (w BankWrapper) MintAmountToAccount(ctx context.Context, recipientAddr sdk.
 func (w BankWrapper) BurnAmountFromAccount(ctx context.Context, account sdk.AccAddress, amt *big.Int) error {
 	coin := sdk.Coin{Denom: config.GetEVMCoinDenom(), Amount: sdkmath.NewIntFromBigInt(amt)}
 
-	convertedCoin, err := convertEvmCoinFrom18Decimals(coin)
+	convertedCoin, err := ConvertEvmCoinFrom18Decimals(coin)
 	if err != nil {
 		return errors.Wrap(err, "failed to burn coins from account in bank wrapper")
 	}
@@ -83,14 +83,14 @@ func (w BankWrapper) GetBalance(ctx context.Context, addr sdk.AccAddress, denom
 	// representation used in the evm.
 	coin := w.BankKeeper.GetBalance(ctx, addr, denom)
 
-	return mustConvertEvmCoinTo18Decimals(coin)
+	return MustConvertEvmCoinTo18Decimals(coin)
 }
 
 // SendCoinsFromAccountToModule wraps around the Cosmos SDK x/bank module's
 // SendCoinsFromAccountToModule method to convert the evm coin, if present in
 // the input, to its original representation.
 func (w BankWrapper) SendCoinsFromAccountToModule(ctx context.Context, senderAddr sdk.AccAddress, recipientModule string, coins sdk.Coins) error {
-	convertedCoins := convertCoinsFrom18Decimals(coins)
+	convertedCoins := ConvertCoinsFrom18Decimals(coins)
 
 	return w.BankKeeper.SendCoinsFromAccountToModule(ctx, senderAddr, recipientModule, convertedCoins)
 }
@@ -99,7 +99,7 @@ func (w BankWrapper) SendCoinsFromAccountToModule(ctx context.Context, senderAdd
 // SendCoinsFromModuleToAccount method to convert the evm coin, if present in
 // the input, to its original representation.
 func (w BankWrapper) SendCoinsFromModuleToAccount(ctx context.Context, senderModule string, recipientAddr sdk.AccAddress, coins sdk.Coins) error {
-	convertedCoins := convertCoinsFrom18Decimals(coins)
+	convertedCoins := ConvertCoinsFrom18Decimals(coins)
 
 	return w.BankKeeper.SendCoinsFromModuleToAccount(ctx, senderModule, recipientAddr, convertedCoins)
 }
@@ -5,16 +5,17 @@ package wrappers
 
 import (
 	"fmt"
+	"math/big"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 
 	"github.com/evmos/evmos/v20/x/evm/config"
 )
 
-// mustConvertEvmCoinTo18Decimals converts the coin's Amount from its original
+// MustConvertEvmCoinTo18Decimals converts the coin's Amount from its original
 // representation into a 18 decimals. The function panics if coin denom is
 // not the evm denom or in case of overflow.
-func mustConvertEvmCoinTo18Decimals(coin sdk.Coin) sdk.Coin {
+func MustConvertEvmCoinTo18Decimals(coin sdk.Coin) sdk.Coin {
 	if coin.Denom != config.GetEVMCoinDenom() {
 		panic(fmt.Sprintf("expected evm denom %s, received %s", config.GetEVMCoinDenom(), coin.Denom))
 	}
@@ -25,9 +26,9 @@ func mustConvertEvmCoinTo18Decimals(coin sdk.Coin) sdk.Coin {
 	return sdk.Coin{Denom: coin.Denom, Amount: newAmount}
 }
 
-// convertEvmCoinFrom18Decimals converts the coin's Amount from 18 decimals to its
+// ConvertEvmCoinFrom18Decimals converts the coin's Amount from 18 decimals to its
 // original representation. Return an error if the coin denom is not the EVM.
-func convertEvmCoinFrom18Decimals(coin sdk.Coin) (sdk.Coin, error) {
+func ConvertEvmCoinFrom18Decimals(coin sdk.Coin) (sdk.Coin, error) {
 	if coin.Denom != config.GetEVMCoinDenom() {
 		return sdk.Coin{}, fmt.Errorf("expected coin denom %s, received %s", config.GetEVMCoinDenom(), coin.Denom)
 	}
@@ -38,9 +39,9 @@ func convertEvmCoinFrom18Decimals(coin sdk.Coin) (sdk.Coin, error) {
 	return sdk.Coin{Denom: coin.Denom, Amount: newAmount}, nil
 }
 
-// convertCoinsFrom18Decimals returns the given coins with the Amount of the evm
+// ConvertCoinsFrom18Decimals returns the given coins with the Amount of the evm
 // coin converted from the 18 decimals representation to the original one.
-func convertCoinsFrom18Decimals(coins sdk.Coins) sdk.Coins {
+func ConvertCoinsFrom18Decimals(coins sdk.Coins) sdk.Coins {
 	evmDenom := config.GetEVMCoinDenom()
 
 	convertedCoins := make(sdk.Coins, len(coins))
@@ -56,3 +57,17 @@ func convertCoinsFrom18Decimals(coins sdk.Coins) sdk.Coins {
 	}
 	return convertedCoins
 }
+
+// AdjustExtraDecimalsBigInt replaces all extra decimals by zero of an amount with 18 decimals in big.Int when having a decimal configuration different than 18 decimals
+func AdjustExtraDecimalsBigInt(amt *big.Int) *big.Int {
+	if amt.Sign() == 0 {
+		return amt
+	}
+	dec := config.GetEVMCoinDecimals()
+	if dec == config.EighteenDecimals {
+		return amt
+	}
+	scaleFactor := dec.ConversionFactor()
+	scaledDown := new(big.Int).Quo(amt, scaleFactor.BigInt())
+	return new(big.Int).Mul(scaledDown, scaleFactor.BigInt())
+}
@@ -1,15 +1,18 @@
 // Copyright Tharsis Labs Ltd.(Evmos)
 // SPDX-License-Identifier:ENCL-1.0(https://github.com/evmos/evmos/blob/main/LICENSE)
 
-package wrappers
+package wrappers_test
 
 import (
+	"fmt"
+	"math/big"
 	"testing"
 
 	"cosmossdk.io/math"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/evmos/evmos/v20/types"
 	"github.com/evmos/evmos/v20/x/evm/config"
+	"github.com/evmos/evmos/v20/x/evm/wrappers"
 
 	"github.com/stretchr/testify/require"
 )
@@ -76,7 +79,7 @@ func TestMustConvertEvmCoinTo18Decimals(t *testing.T) {
 
 			config.SetEVMCoinTEST(tc.evmCoinInfo)
 
-			coinConverted := mustConvertEvmCoinTo18Decimals(tc.coin)
+			coinConverted := wrappers.MustConvertEvmCoinTo18Decimals(tc.coin)
 
 			if !tc.expPanic {
 				require.Equal(t, tc.expCoin, coinConverted, "expected a different coin")
@@ -140,7 +143,7 @@ func TestConvertEvmCoinFrom18Decimals(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			config.SetEVMCoinTEST(tc.evmCoinInfo)
 
-			coinConverted, err := convertEvmCoinFrom18Decimals(tc.coin)
+			coinConverted, err := wrappers.ConvertEvmCoinFrom18Decimals(tc.coin)
 
 			if !tc.expErr {
 				require.NoError(t, err)
@@ -198,8 +201,63 @@ func TestConvertCoinsFrom18Decimals(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			config.SetEVMCoinTEST(tc.evmCoinInfo)
 
-			coinConverted := convertCoinsFrom18Decimals(tc.coins)
+			coinConverted := wrappers.ConvertCoinsFrom18Decimals(tc.coins)
 			require.Equal(t, tc.expCoins, coinConverted, "expected a different coin")
 		})
 	}
 }
+
+func TestZeroExtraDecimalsBigInt(t *testing.T) {
+	testCases := []struct {
+		name string
+		amt  *big.Int
+		exp  *big.Int
+	}{
+		{
+			name: "almost 1: 0.99999...",
+			amt:  big.NewInt(999999999999),
+			exp:  big.NewInt(0),
+		},
+		{
+			name: "decimal < 5: 1.4",
+			amt:  big.NewInt(14e11),
+			exp:  big.NewInt(1e12),
+		},
+		{
+			name: "decimal < 5: 1.499999999999",
+			amt:  big.NewInt(1499999999999),
+			exp:  big.NewInt(1e12),
+		},
+		{
+			name: "decimal == 5: 1.5",
+			amt:  big.NewInt(15e11),
+			exp:  big.NewInt(1e12),
+		},
+		{
+			name: "decimal > 5: 1.9",
+			amt:  big.NewInt(19e11),
+			exp:  big.NewInt(1e12),
+		},
+		{
+			name: "1 wei",
+			amt:  big.NewInt(1),
+			exp:  big.NewInt(0),
+		},
+	}
+
+	for _, cfg := range []config.EvmCoinInfo{
+		{Denom: types.BaseDenom, Decimals: config.SixDecimals},
+		{Denom: types.BaseDenom, Decimals: config.EighteenDecimals},
+	} {
+		for _, tc := range testCases {
+			t.Run(fmt.Sprintf("%d dec - %s", cfg.Decimals, tc.name), func(t *testing.T) {
+				config.SetEVMCoinTEST(cfg)
+				res := wrappers.AdjustExtraDecimalsBigInt(tc.amt)
+				if cfg.Decimals == config.EighteenDecimals {
+					tc.exp = tc.amt
+				}
+				require.Equal(t, tc.exp, res)
+			})
+		}
+	}
+}