From de14541ad4a99854c42ea4663901e219622e7b51 Mon Sep 17 00:00:00 2001
From: Kelvin Fichter <kelvin@optimism.io>
Date: Mon, 24 Jan 2022 12:29:42 -0500
Subject: [PATCH] feat(sdk): implement L2 message gas estimation
---
packages/sdk/src/cross-chain-provider.ts | 22 ++++-
.../src/interfaces/cross-chain-provider.ts | 9 +-
.../sdk/test/cross-chain-provider.spec.ts | 89 ++++++++++++++++++-
3 files changed, 116 insertions(+), 4 deletions(-)
diff --git a/packages/sdk/src/cross-chain-provider.ts b/packages/sdk/src/cross-chain-provider.ts
index 455f1ac1b..8acc1ecf5 100644
--- a/packages/sdk/src/cross-chain-provider.ts
+++ b/packages/sdk/src/cross-chain-provider.ts
@@ -421,9 +421,27 @@ export class CrossChainProvider implements ICrossChainProvider {
}
public async estimateL2MessageGasLimit(
- message: MessageLike
+ message: MessageLike,
+ opts?: {
+ bufferPercent?: number
+ }
): Promise<BigNumber> {
- throw new Error('Not implemented')
+ const resolved = await this.toCrossChainMessage(message)
+
+ // L2 message gas estimation is only used for L1 => L2 messages.
+ if (resolved.direction === MessageDirection.L2_TO_L1) {
+ throw new Error(`cannot estimate gas limit for L2 => L1 message`)
+ }
+
+ const estimate = await this.l2Provider.estimateGas({
+ from: resolved.sender,
+ to: resolved.target,
+ data: resolved.message,
+ })
+
+ // Return the estimate plus a buffer of 20% just in case.
+ const bufferPercent = opts?.bufferPercent || 20
+ return estimate.mul(100 + bufferPercent).div(100)
}
public async estimateMessageWaitTimeSeconds(
diff --git a/packages/sdk/src/interfaces/cross-chain-provider.ts b/packages/sdk/src/interfaces/cross-chain-provider.ts
index fb75a751e..5fe4541f7 100644
--- a/packages/sdk/src/interfaces/cross-chain-provider.ts
+++ b/packages/sdk/src/interfaces/cross-chain-provider.ts
@@ -201,9 +201,16 @@ export interface ICrossChainProvider {
* L1 => L2 messages. You would supply this gas limit when sending the message to L2.
*
* @param message Message get a gas estimate for.
+ * @param opts Options object.
+ * @param opts.bufferPercent Percentage of gas to add to the estimate. Defaults to 20.
* @returns Estimates L2 gas limit.
*/
- estimateL2MessageGasLimit(message: MessageLike): Promise<BigNumber>
+ estimateL2MessageGasLimit(
+ message: MessageLike,
+ opts?: {
+ bufferPercent?: number
+ }
+ ): Promise<BigNumber>
/**
* Returns the estimated amount of time before the message can be executed. When this is a
diff --git a/packages/sdk/test/cross-chain-provider.spec.ts b/packages/sdk/test/cross-chain-provider.spec.ts
index a4adc58cc..8d8fc34d1 100644
--- a/packages/sdk/test/cross-chain-provider.spec.ts
+++ b/packages/sdk/test/cross-chain-provider.spec.ts
@@ -1,4 +1,5 @@
import { Provider } from '@ethersproject/abstract-provider'
+import { expectApprox } from '@eth-optimism/core-utils'
import { Contract } from 'ethers'
import { ethers } from 'hardhat'
@@ -1091,7 +1092,93 @@ describe('CrossChainProvider', () => {
})
describe('estimateL2MessageGasLimit', () => {
- it('should perform a gas estimation of the L2 action')
+ let provider: CrossChainProvider
+ beforeEach(async () => {
+ provider = new CrossChainProvider({
+ l1Provider: ethers.provider,
+ l2Provider: ethers.provider,
+ l1ChainId: 31337,
+ })
+ })
+
+ describe('when the message is an L1 to L2 message', () => {
+ it('should return an accurate gas estimate plus a ~20% buffer', async () => {
+ const message = {
+ direction: MessageDirection.L1_TO_L2,
+ target: '0x' + '11'.repeat(20),
+ sender: '0x' + '22'.repeat(20),
+ message: '0x' + '33'.repeat(64),
+ messageNonce: 1234,
+ logIndex: 0,
+ blockNumber: 1234,
+ transactionHash: '0x' + '44'.repeat(32),
+ }
+
+ const estimate = await ethers.provider.estimateGas({
+ to: message.target,
+ from: message.sender,
+ data: message.message,
+ })
+
+ // Approximately 20% greater than the estimate, +/- 1%.
+ expectApprox(
+ await provider.estimateL2MessageGasLimit(message),
+ estimate.mul(120).div(100),
+ {
+ percentUpperDeviation: 1,
+ percentLowerDeviation: 1,
+ }
+ )
+ })
+
+ it('should return an accurate gas estimate when a custom buffer is provided', async () => {
+ const message = {
+ direction: MessageDirection.L1_TO_L2,
+ target: '0x' + '11'.repeat(20),
+ sender: '0x' + '22'.repeat(20),
+ message: '0x' + '33'.repeat(64),
+ messageNonce: 1234,
+ logIndex: 0,
+ blockNumber: 1234,
+ transactionHash: '0x' + '44'.repeat(32),
+ }
+
+ const estimate = await ethers.provider.estimateGas({
+ to: message.target,
+ from: message.sender,
+ data: message.message,
+ })
+
+ // Approximately 30% greater than the estimate, +/- 1%.
+ expectApprox(
+ await provider.estimateL2MessageGasLimit(message, {
+ bufferPercent: 30,
+ }),
+ estimate.mul(130).div(100),
+ {
+ percentUpperDeviation: 1,
+ percentLowerDeviation: 1,
+ }
+ )
+ })
+ })
+
+ describe('when the message is an L2 to L1 message', () => {
+ it('should throw an error', async () => {
+ const message = {
+ direction: MessageDirection.L2_TO_L1,
+ target: '0x' + '11'.repeat(20),
+ sender: '0x' + '22'.repeat(20),
+ message: '0x' + '33'.repeat(64),
+ messageNonce: 1234,
+ logIndex: 0,
+ blockNumber: 1234,
+ transactionHash: '0x' + '44'.repeat(32),
+ }
+
+ await expect(provider.estimateL2MessageGasLimit(message)).to.be.rejected
+ })
+ })
})
describe('estimateMessageWaitTimeBlocks', () => {
--
2.23.0