Merge pull request onflow#5432 from onflow/ramtin/flow-evm-disable-ba…

…se-fee

[Flow EVM] Add test for tx with zero fee or dynamic fees

fvm/evm/emulator/config.go

@@ -73,10 +73,15 @@ var DefaultChainConfig = &gethParams.ChainConfig{
 	PragueTime:   &zero, // already on Prague
 }
 
+// Default config supports the dynamic fee structure (EIP-1559)
+// so it accepts both legacy transactions with a fixed gas price
+// and dynamic transactions with tip and cap.
+// Yet default config keeps the base fee to zero (no automatic adjustment)
 func defaultConfig() *Config {
 	return &Config{
 		ChainConfig: DefaultChainConfig,
 		EVMConfig: gethVM.Config{
+			// setting this flag let us we force the base fee to zero (coinbase will collect)
 			NoBaseFee: true,
 		},
 		TxContext: &gethVM.TxContext{

fvm/evm/emulator/emulator_test.go

@@ -233,8 +233,10 @@ func TestContractInteraction(t *testing.T) {
 						gethCommon.Big1,        // gas fee
 
 					)
-					_, err = blk.RunTransaction(tx)
+					res, err := blk.RunTransaction(tx)
 					require.NoError(t, err)
+					require.NoError(t, res.VMError)
+					require.Greater(t, res.GasConsumed, uint64(0))
 
 					// check the balance of coinbase
 					RunWithNewReadOnlyBlockView(t, env, func(blk2 types.ReadOnlyBlockView) {
@@ -249,6 +251,50 @@ func TestContractInteraction(t *testing.T) {
 					})
 				})
 			})
+
+			t.Run("test runing transactions with dynamic fees (happy case)", func(t *testing.T) {
+				account := testutils.GetTestEOAAccount(t, testutils.EOATestAccount1KeyHex)
+				fAddr := account.Address()
+				RunWithNewEmulator(t, backend, rootAddr, func(env *emulator.Emulator) {
+					RunWithNewBlockView(t, env, func(blk types.BlockView) {
+						_, err := blk.DirectCall(types.NewDepositCall(fAddr, amount, account.Nonce()))
+						require.NoError(t, err)
+					})
+				})
+				account.SetNonce(account.Nonce() + 1)
+
+				RunWithNewEmulator(t, backend, rootAddr, func(env *emulator.Emulator) {
+					ctx := types.NewDefaultBlockContext(blockNumber.Uint64())
+					ctx.GasFeeCollector = types.NewAddressFromString("coinbase")
+					coinbaseOrgBalance := gethCommon.Big1
+					// small amount of money to create account
+					RunWithNewBlockView(t, env, func(blk types.BlockView) {
+						_, err := blk.DirectCall(types.NewDepositCall(ctx.GasFeeCollector, coinbaseOrgBalance, 1))
+						require.NoError(t, err)
+					})
+
+					blk, err := env.NewBlockView(ctx)
+					require.NoError(t, err)
+					tx := account.SignTx(
+						t,
+						gethTypes.NewTx(&gethTypes.DynamicFeeTx{
+							Nonce:     account.Nonce(),
+							GasTipCap: big.NewInt(2),
+							GasFeeCap: big.NewInt(3),
+							Gas:       gethParams.TxGas,
+							To:        &gethCommon.Address{},
+							Value:     big.NewInt(1),
+						}),
+					)
+					account.SetNonce(account.Nonce() + 1)
+
+					res, err := blk.RunTransaction(tx)
+					require.NoError(t, err)
+					require.NoError(t, res.VMError)
+					require.Greater(t, res.GasConsumed, uint64(0))
+				})
+			})
+
 			t.Run("test sending transactions (invalid nonce)", func(t *testing.T) {
 				account := testutils.GetTestEOAAccount(t, testutils.EOATestAccount1KeyHex)
 				fAddr := account.Address()

fvm/evm/types/call.go

@@ -21,6 +21,10 @@ const (
 	DeployCallSubType   = byte(4)
 	ContractCallSubType = byte(5)
 
+	// Note that these gas values might need to change if we
+	// change the transaction (e.g. add accesslist),
+	// then it has to be updated to use Intrinsic function
+	// to calculate the minimum gas needed to run the transaction.
 	DepositCallGasLimit  = gethParams.TxGas
 	WithdrawCallGasLimit = gethParams.TxGas
 
@@ -71,8 +75,8 @@ func (dc *DirectCall) Message() *gethCore.Message {
 		Nonce:     dc.Nonce,
 		GasLimit:  dc.GasLimit,
 		GasPrice:  big.NewInt(0), // price is set to zero fo direct calls
-		GasTipCap: big.NewInt(1), // also known as maxPriorityFeePerGas (in GWei)
-		GasFeeCap: big.NewInt(2), // also known as maxFeePerGas (in GWei)
+		GasTipCap: big.NewInt(0), // also known as maxPriorityFeePerGas (in GWei)
+		GasFeeCap: big.NewInt(0), // also known as maxFeePerGas (in GWei)
 		// AccessList:        tx.AccessList(), // TODO revisit this value, the cost matter but performance might
 		SkipAccountChecks: true, // this would let us not set the nonce
 	}