op-e2e: Extract helper for sending transactions with padded gas limit

op-e2e/e2eutils/disputegame/helper.go

@@ -15,12 +15,14 @@ import (
 	"github.com/ethereum-optimism/optimism/op-challenger/fault/alphabet"
 	"github.com/ethereum-optimism/optimism/op-challenger/fault/cannon"
 	"github.com/ethereum-optimism/optimism/op-e2e/e2eutils/challenger"
+	"github.com/ethereum-optimism/optimism/op-e2e/e2eutils/transactions"
 	"github.com/ethereum-optimism/optimism/op-e2e/e2eutils/wait"
 	"github.com/ethereum-optimism/optimism/op-node/rollup"
 	"github.com/ethereum-optimism/optimism/op-node/testlog"
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/stretchr/testify/require"
@@ -106,14 +108,9 @@ func (h *FactoryHelper) StartAlphabetGame(ctx context.Context, claimedAlphabet s
 	extraData := make([]byte, 64)
 	binary.BigEndian.PutUint64(extraData[24:], l2BlockNumber)
 	binary.BigEndian.PutUint64(extraData[56:], l1Head.Uint64())
-	h.opts.NoSend = true
-	tx, err := h.factory.Create(h.opts, alphabetGameType, rootClaim, extraData)
-	h.require.NoError(err, "create fault dispute game (estimate gas)")
-
-	// Now send with increased gas. This provides a buffer if the output oracle search is now more expensive
-	h.opts.NoSend = false
-	h.opts.GasLimit = tx.Gas() * 2
-	tx, err = h.factory.Create(h.opts, alphabetGameType, rootClaim, extraData)
+	tx, err := transactions.PadGasEstimate(h.opts, 2, func(opts *bind.TransactOpts) (*types.Transaction, error) {
+		return h.factory.Create(opts, alphabetGameType, rootClaim, extraData)
+	})
 	h.require.NoError(err, "create fault dispute game")
 	h.opts.GasLimit = 0
 	rcpt, err := wait.ForReceiptOK(ctx, h.client, tx.Hash())
@@ -199,16 +196,10 @@ func (h *FactoryHelper) createCannonGame(ctx context.Context, l2BlockNumber uint
 	extraData := make([]byte, 64)
 	binary.BigEndian.PutUint64(extraData[24:], l2BlockNumber)
 	binary.BigEndian.PutUint64(extraData[56:], l1Head.Uint64())
-	h.opts.NoSend = true
-	tx, err := h.factory.Create(h.opts, cannonGameType, rootClaim, extraData)
-	h.require.NoError(err, "create fault dispute game (estimate gas)")
-
-	// Now send with increased gas. This provides a buffer if the output oracle search is now more expensive
-	h.opts.NoSend = false
-	h.opts.GasLimit = tx.Gas() * 2
-	tx, err = h.factory.Create(h.opts, cannonGameType, rootClaim, extraData)
+	tx, err := transactions.PadGasEstimate(h.opts, 2, func(opts *bind.TransactOpts) (*types.Transaction, error) {
+		return h.factory.Create(opts, cannonGameType, rootClaim, extraData)
+	})
 	h.require.NoError(err, "create fault dispute game")
-	h.opts.GasLimit = 0
 	rcpt, err := wait.ForReceiptOK(ctx, h.client, tx.Hash())
 	h.require.NoError(err, "wait for create fault dispute game receipt to be OK")
 	h.require.Len(rcpt.Logs, 1, "should have emitted a single DisputeGameCreated event")

op-e2e/e2eutils/transactions/gas.go

+package transactions
+
+import (
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/accounts/abi/bind"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+// TxBuilder creates and sends a transaction using the supplied bind.TransactOpts.
+// Returns the created transaction and any error reported.
+type TxBuilder func(opts *bind.TransactOpts) (*types.Transaction, error)
+
+// PadGasEstimate multiplies the gas estimate for a transaction by the specified paddingFactor before sending the
+// actual transaction. Useful for cases where the gas required is variable.
+// The builder will be invoked twice, first with NoSend=true to estimate the gas and the second time with
+// NoSend=false and GasLimit including the requested padding.
+func PadGasEstimate(opts *bind.TransactOpts, paddingFactor float64, builder TxBuilder) (*types.Transaction, error) {
+	// Take a copy of the opts to avoid mutating the original
+	o := *opts
+	o.NoSend = true
+	tx, err := builder(&o)
+	if err != nil {
+		return nil, fmt.Errorf("failed to estimate gas: %w", err)
+	}
+	gas := float64(tx.Gas()) * paddingFactor
+	o.GasLimit = uint64(gas)
+	o.NoSend = false
+	return builder(&o)
+}

op-e2e/tx_helper.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/ethereum-optimism/optimism/op-bindings/bindings"
+	"github.com/ethereum-optimism/optimism/op-e2e/e2eutils/transactions"
 	"github.com/ethereum-optimism/optimism/op-node/rollup/derive"
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
@@ -29,19 +30,12 @@ func SendDepositTx(t *testing.T, cfg SystemConfig, l1Client *ethclient.Client, l
 	require.Nil(t, err)
 
 	// Finally send TX
-	l1Opts.NoSend = true
-	tx, err := depositContract.DepositTransaction(l1Opts, l2Opts.ToAddr, l2Opts.Value, l2Opts.GasLimit, l2Opts.IsCreation, l2Opts.Data)
-	require.Nil(t, err, "with deposit tx")
-
-	l1Opts.NoSend = false
 	// Add 10% padding for the L1 gas limit because the estimation process can be affected by the 1559 style cost scale
 	// for buying L2 gas in the portal contracts.
-	l1Opts.GasLimit = tx.Gas() + (tx.Gas() / 10)
-
-	// Now resend with gas specified
-	tx, err = depositContract.DepositTransaction(l1Opts, l2Opts.ToAddr, l2Opts.Value, l2Opts.GasLimit, l2Opts.IsCreation, l2Opts.Data)
+	tx, err := transactions.PadGasEstimate(l1Opts, 1.1, func(opts *bind.TransactOpts) (*types.Transaction, error) {
+		return depositContract.DepositTransaction(opts, l2Opts.ToAddr, l2Opts.Value, l2Opts.GasLimit, l2Opts.IsCreation, l2Opts.Data)
+	})
 	require.Nil(t, err, "with deposit tx")
-	l1Opts.GasLimit = 0
 
 	// Wait for transaction on L1
 	receipt, err := waitForTransaction(tx.Hash(), l1Client, 10*time.Duration(cfg.DeployConfig.L1BlockTime)*time.Second)