evm: estimate gas unit tests (#324)

* add some unit tests for estimateGas

Also add some test environment setup, Closes #323

test estimateGas of erc20 token transfer

fix failed test case

the trick is to keep a clean transient store, by doing a commit

put artifacts to external file

* fix test failure

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

.github/workflows/test.yml

@@ -15,7 +15,7 @@ jobs:
   #     - uses: actions/checkout@v2.3.4
   #     - uses: actions/setup-go@v2.1.3
   #       with:
-  #         go-version: 1.15
+  #         go-version: 1.16
   #     - uses: technote-space/get-diff-action@v4.2
   #       id: git_diff
   #       with:
@@ -62,7 +62,7 @@ jobs:
       - uses: actions/checkout@v2.3.4
       - uses: actions/setup-go@v2.1.3
         with:
-          go-version: 1.15
+          go-version: 1.16
       - uses: technote-space/get-diff-action@v4.2
         id: git_diff
         with:
@@ -101,7 +101,7 @@ jobs:
       - uses: actions/checkout@v2.3.4
       - uses: actions/setup-go@v2.1.3
         with:
-          go-version: 1.15
+          go-version: 1.16
       - uses: technote-space/get-diff-action@v4.2
         id: git_diff
         with:
@@ -140,7 +140,7 @@ jobs:
       - uses: actions/checkout@v2.3.4
       - uses: actions/setup-go@v2.1.3
         with:
-          go-version: 1.15
+          go-version: 1.16
       - uses: technote-space/get-diff-action@v4.2
         id: git_diff
         with:
@@ -179,7 +179,7 @@ jobs:
       - uses: actions/checkout@v2.3.4
       - uses: actions/setup-go@v2.1.3
         with:
-          go-version: 1.15
+          go-version: 1.16
       - uses: technote-space/get-diff-action@v4.2
         id: git_diff
         with:
@@ -218,7 +218,7 @@ jobs:
   #     - uses: actions/checkout@v2.3.4
   #     - uses: actions/setup-go@v2.1.3
   #       with:
-  #         go-version: 1.15
+  #         go-version: 1.16
   #     - uses: technote-space/get-diff-action@v4.2
   #       id: git_diff
   #       with:

go.mod

@@ -1,6 +1,6 @@
 module github.com/tharsis/ethermint
 
-go 1.15
+go 1.16
 
 require (
 	github.com/armon/go-metrics v0.3.9

scripts/gen-tests-artifacts.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+# prepare sloc v0.5.17 in PATH
+solc --combined-json bin,abi --allow-paths . ./tests/solidity/suites/staking/contracts/test/mocks/StandardTokenMock.sol \
+    | jq ".contracts.\"./tests/solidity/suites/staking/contracts/test/mocks/StandardTokenMock.sol:StandardTokenMock\"" \
+    > x/evm/keeper/ERC20Contract.json

x/evm/keeper/grpc_query.go

@@ -406,6 +406,10 @@ func (k Keeper) EstimateGas(c context.Context, req *types.EthCallRequest) (*type
 	ctx := sdk.UnwrapSDKContext(c)
 	k.WithContext(ctx)
 
+	if req.GasCap < ethparams.TxGas {
+		return nil, status.Error(codes.InvalidArgument, "gas cap cannot be lower than 21,000")
+	}
+
 	var args types.CallArgs
 	err := json.Unmarshal(req.Args, &args)
 	if err != nil {

x/evm/keeper/grpc_query_test.go

@@ -1,13 +1,19 @@
 package keeper_test
 
 import (
+	_ "embed"
+	"encoding/json"
 	"fmt"
+	"math/big"
 
 	"google.golang.org/grpc/metadata"
 
+	"github.com/ethereum/go-ethereum/accounts/abi"
 	"github.com/ethereum/go-ethereum/common"
 	ethcmn "github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	ethtypes "github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
 	ethcrypto "github.com/ethereum/go-ethereum/crypto"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -21,6 +27,29 @@ import (
 //Not valid Ethereum address
 const invalidAddress = "0x0000"
 
+var (
+	//go:embed ERC20Contract.json
+	compiledContractJSON []byte
+	contractBin          []byte
+	contractABI          abi.ABI
+)
+
+func init() {
+	var tmp struct {
+		Abi string
+		Bin string
+	}
+	err := json.Unmarshal(compiledContractJSON, &tmp)
+	if err != nil {
+		panic(err)
+	}
+	contractBin = common.FromHex(tmp.Bin)
+	err = json.Unmarshal([]byte(tmp.Abi), &contractABI)
+	if err != nil {
+		panic(err)
+	}
+}
+
 func (suite *KeeperTestSuite) TestQueryAccount() {
 	var (
 		req        *types.QueryAccountRequest
@@ -686,3 +715,122 @@ func (suite *KeeperTestSuite) TestQueryValidatorAccount() {
 		})
 	}
 }
+
+// DeployTestContract deploy a test erc20 contract and returns the contract address
+func (suite *KeeperTestSuite) deployTestContract(owner common.Address, supply *big.Int) common.Address {
+	ctx := sdk.WrapSDKContext(suite.ctx)
+	chainID := suite.app.EvmKeeper.ChainID()
+
+	ctorArgs, err := contractABI.Pack("", owner, supply)
+	suite.Require().NoError(err)
+
+	data := append(contractBin, ctorArgs...)
+	args, err := json.Marshal(&types.CallArgs{
+		From: &suite.address,
+		Data: (*hexutil.Bytes)(&data),
+	})
+	suite.Require().NoError(err)
+
+	res, err := suite.queryClient.EstimateGas(ctx, &types.EthCallRequest{
+		Args:   args,
+		GasCap: uint64(ethermint.DefaultRPCGasLimit),
+	})
+	suite.Require().NoError(err)
+
+	nonce := suite.app.EvmKeeper.GetNonce(suite.address)
+	erc20DeployTx := types.NewTxContract(
+		chainID,
+		nonce,
+		nil,     // amount
+		res.Gas, // gasLimit
+		nil,     // gasPrice
+		data,    // input
+		nil,     // accesses
+	)
+	erc20DeployTx.From = suite.address.Hex()
+	err = erc20DeployTx.Sign(ethtypes.LatestSignerForChainID(chainID), suite.signer)
+	suite.Require().NoError(err)
+	rsp, err := suite.app.EvmKeeper.EthereumTx(ctx, erc20DeployTx)
+	suite.Require().NoError(err)
+	suite.Require().Empty(rsp.VmError)
+	return crypto.CreateAddress(suite.address, nonce)
+}
+
+func (suite *KeeperTestSuite) TestEstimateGas() {
+	ctx := sdk.WrapSDKContext(suite.ctx)
+	gasHelper := hexutil.Uint64(20000)
+
+	var (
+		args   types.CallArgs
+		gasCap uint64
+	)
+	testCases := []struct {
+		msg      string
+		malleate func()
+		expPass  bool
+		expGas   uint64
+	}{
+		// should success, because transfer value is zero
+		{"default args", func() {
+			args = types.CallArgs{To: &common.Address{}}
+		}, true, 21000},
+		// should fail, because the default From address(zero address) don't have fund
+		{"not enough balance", func() {
+			args = types.CallArgs{To: &common.Address{}, Value: (*hexutil.Big)(big.NewInt(100))}
+		}, false, 0},
+		// should success, enough balance now
+		{"enough balance", func() {
+			args = types.CallArgs{To: &common.Address{}, From: &suite.address, Value: (*hexutil.Big)(big.NewInt(100))}
+		}, false, 0},
+		// should success, because gas limit lower than 21000 is ignored
+		{"gas exceed allowance", func() {
+			args = types.CallArgs{To: &common.Address{}, Gas: &gasHelper}
+		}, true, 21000},
+		// should fail, invalid gas cap
+		{"gas exceed global allowance", func() {
+			args = types.CallArgs{To: &common.Address{}}
+			gasCap = 20000
+		}, false, 0},
+		// estimate gas of an erc20 contract deployment, the exact gas number is checked with geth
+		{"contract deployment", func() {
+			ctorArgs, err := contractABI.Pack("", &suite.address, sdk.NewIntWithDecimal(1000, 18).BigInt())
+			suite.Require().NoError(err)
+			data := append(contractBin, ctorArgs...)
+			args = types.CallArgs{
+				From: &suite.address,
+				Data: (*hexutil.Bytes)(&data),
+			}
+		}, true, 1144643},
+		// estimate gas of an erc20 transfer, the exact gas number is checked with geth
+		{"erc20 transfer", func() {
+			contractAddr := suite.deployTestContract(suite.address, sdk.NewIntWithDecimal(1000, 18).BigInt())
+			suite.Commit()
+			transferData, err := contractABI.Pack("transfer", common.HexToAddress("0x378c50D9264C63F3F92B806d4ee56E9D86FfB3Ec"), big.NewInt(1000))
+			suite.Require().NoError(err)
+			args = types.CallArgs{To: &contractAddr, From: &suite.address, Data: (*hexutil.Bytes)(&transferData)}
+		}, true, 51880},
+	}
+
+	for _, tc := range testCases {
+		suite.Run(fmt.Sprintf("Case %s", tc.msg), func() {
+			suite.SetupTest()
+			gasCap = ethermint.DefaultRPCGasLimit
+			tc.malleate()
+
+			args, err := json.Marshal(&args)
+			suite.Require().NoError(err)
+			req := types.EthCallRequest{
+				Args:   args,
+				GasCap: gasCap,
+			}
+
+			rsp, err := suite.queryClient.EstimateGas(ctx, &req)
+			if tc.expPass {
+				suite.Require().NoError(err)
+				suite.Require().Equal(tc.expGas, rsp.Gas)
+			} else {
+				suite.Require().Error(err)
+			}
+		})
+	}
+}

x/evm/keeper/keeper_test.go

@@ -8,13 +8,19 @@ import (
 
 	"github.com/cosmos/cosmos-sdk/baseapp"
 	"github.com/cosmos/cosmos-sdk/client"
+	"github.com/cosmos/cosmos-sdk/codec"
+	"github.com/cosmos/cosmos-sdk/crypto/keyring"
+	"github.com/cosmos/cosmos-sdk/simapp"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	authkeeper "github.com/cosmos/cosmos-sdk/x/auth/keeper"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
+	bankkeeper "github.com/cosmos/cosmos-sdk/x/bank/keeper"
 	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
 
 	"github.com/tharsis/ethermint/app"
 	"github.com/tharsis/ethermint/crypto/ethsecp256k1"
 	"github.com/tharsis/ethermint/encoding"
+	"github.com/tharsis/ethermint/tests"
 	ethermint "github.com/tharsis/ethermint/types"
 	"github.com/tharsis/ethermint/x/evm/types"
 
@@ -23,15 +29,11 @@ import (
 	ethtypes "github.com/ethereum/go-ethereum/core/types"
 	ethcrypto "github.com/ethereum/go-ethereum/crypto"
 
+	abci "github.com/tendermint/tendermint/abci/types"
 	tmproto "github.com/tendermint/tendermint/proto/tendermint/types"
 )
 
-const addrHex = "0x756F45E3FA69347A9A973A725E3C98bC4db0b4c1"
+var testTokens = sdk.NewIntWithDecimal(1000, 18)
-const hex = "0x0d87a3a5f73140f46aac1bf419263e4e94e87c292f25007700ab7f2060e2af68"
-
-var (
-	hash = ethcmn.FromHex(hex)
-)
 
 type KeeperTestSuite struct {
 	suite.Suite
@@ -45,16 +47,33 @@ type KeeperTestSuite struct {
 	// for generate test tx
 	clientCtx client.Context
 	ethSigner ethtypes.Signer
+
+	appCodec codec.Codec
+	signer   keyring.Signer
 }
 
 func (suite *KeeperTestSuite) SetupTest() {
 	checkTx := false
 
-	suite.app = app.Setup(checkTx)
+	// account key
-	suite.ctx = suite.app.BaseApp.NewContext(checkTx, tmproto.Header{Height: 1, ChainID: "ethermint-1", Time: time.Now().UTC()})
+	priv, err := ethsecp256k1.GenerateKey()
-	suite.app.EvmKeeper.WithContext(suite.ctx)
+	suite.Require().NoError(err)
+	suite.address = ethcmn.BytesToAddress(priv.PubKey().Address().Bytes())
+	suite.signer = tests.NewSigner(priv)
 
-	suite.address = ethcmn.HexToAddress(addrHex)
+	// consensus key
+	priv, err = ethsecp256k1.GenerateKey()
+	suite.Require().NoError(err)
+	suite.consAddress = sdk.ConsAddress(priv.PubKey().Address())
+
+	suite.app = app.Setup(checkTx)
+	suite.ctx = suite.app.BaseApp.NewContext(checkTx, tmproto.Header{
+		Height:          1,
+		ChainID:         "ethermint-1",
+		Time:            time.Now().UTC(),
+		ProposerAddress: suite.consAddress.Bytes(),
+	})
+	suite.app.EvmKeeper.WithContext(suite.ctx)
 
 	queryHelper := baseapp.NewQueryServerTestHelper(suite.ctx, suite.app.InterfaceRegistry())
 	types.RegisterQueryServer(queryHelper, suite.app.EvmKeeper)
@@ -67,17 +86,64 @@ func (suite *KeeperTestSuite) SetupTest() {
 
 	suite.app.AccountKeeper.SetAccount(suite.ctx, acc)
 
-	priv, err := ethsecp256k1.GenerateKey()
-	suite.Require().NoError(err)
 	valAddr := sdk.ValAddress(suite.address.Bytes())
 	validator, err := stakingtypes.NewValidator(valAddr, priv.PubKey(), stakingtypes.Description{})
-	suite.app.StakingKeeper.SetValidatorByConsAddr(suite.ctx, validator)
+	err = suite.app.StakingKeeper.SetValidatorByConsAddr(suite.ctx, validator)
+	suite.Require().NoError(err)
+	err = suite.app.StakingKeeper.SetValidatorByConsAddr(suite.ctx, validator)
+	suite.Require().NoError(err)
 	suite.app.StakingKeeper.SetValidator(suite.ctx, validator)
-	suite.consAddress = sdk.ConsAddress(priv.PubKey().Address())
 
 	encodingConfig := encoding.MakeConfig(app.ModuleBasics)
 	suite.clientCtx = client.Context{}.WithTxConfig(encodingConfig.TxConfig)
 	suite.ethSigner = ethtypes.LatestSignerForChainID(suite.app.EvmKeeper.ChainID())
+	suite.appCodec = encodingConfig.Marshaler
+
+	// mint some tokens to coinbase address
+	_, bankKeeper := suite.initKeepersWithmAccPerms()
+	ctx := sdk.WrapSDKContext(suite.ctx)
+	rsp, err := suite.queryClient.Params(ctx, &types.QueryParamsRequest{})
+	suite.Require().NoError(err)
+	initCoin := sdk.NewCoins(sdk.NewCoin(rsp.Params.EvmDenom, testTokens))
+
+	err = simapp.FundAccount(bankKeeper, suite.ctx, acc.GetAddress(), initCoin)
+	suite.Require().NoError(err)
+}
+
+// Commit and begin new block
+func (suite *KeeperTestSuite) Commit() {
+	suite.app.Commit()
+	header := suite.ctx.BlockHeader()
+	header.Height += 1
+	suite.app.BeginBlock(abci.RequestBeginBlock{
+		Header: header,
+	})
+
+	// update ctx
+	suite.ctx = suite.app.BaseApp.NewContext(false, header)
+	suite.app.EvmKeeper.WithContext(suite.ctx)
+
+	queryHelper := baseapp.NewQueryServerTestHelper(suite.ctx, suite.app.InterfaceRegistry())
+	types.RegisterQueryServer(queryHelper, suite.app.EvmKeeper)
+	suite.queryClient = types.NewQueryClient(queryHelper)
+}
+
+// initKeepersWithmAccPerms construct a bank keeper that can mint tokens out of thin air
+func (suite *KeeperTestSuite) initKeepersWithmAccPerms() (authkeeper.AccountKeeper, bankkeeper.BaseKeeper) {
+	maccPerms := app.GetMaccPerms()
+
+	maccPerms[authtypes.Burner] = []string{authtypes.Burner}
+	maccPerms[authtypes.Minter] = []string{authtypes.Minter}
+	authKeeper := authkeeper.NewAccountKeeper(
+		suite.appCodec, suite.app.GetKey(types.StoreKey), suite.app.GetSubspace(types.ModuleName),
+		authtypes.ProtoBaseAccount, maccPerms,
+	)
+	keeper := bankkeeper.NewBaseKeeper(
+		suite.appCodec, suite.app.GetKey(types.StoreKey), authKeeper,
+		suite.app.GetSubspace(types.ModuleName), map[string]bool{},
+	)
+
+	return authKeeper, keeper
 }
 
 func TestKeeperTestSuite(t *testing.T) {

x/evm/keeper/state_transition_test.go

@@ -20,7 +20,12 @@ func (suite *KeeperTestSuite) TestGetCoinbaseAddress() {
 	}{
 		{
 			"validator not found",
-			func() {},
+			func() {
+				header := suite.ctx.BlockHeader()
+				header.ProposerAddress = []byte{}
+				suite.ctx = suite.ctx.WithBlockHeader(header)
+				suite.app.EvmKeeper.WithContext(suite.ctx)
+			},
 			false,
 		},
 		{