feat: non-18 decimal custom gas token support (#445)

.github/workflows/build-test.yml

@@ -124,25 +124,47 @@ jobs:
         run: CI=true yarn test:unit
 
   test-integration:
-    name: Test (Integration) on Node.js v${{ matrix.node-version }}${{ matrix.orbit-test == '1' && ' with L3' || '' }}${{ matrix.custom-fee == '1' && ' with custom gas token' || '' }}
+    name: Test (Integration) on Node.js v${{ matrix.node-version }}${{ matrix.orbit-test == '1' && ' with L3' || '' }}${{ matrix.decimals == '16' && ' with custom gas token (16 decimals)' || matrix.decimals == '20' && ' with custom gas token (20 decimals)' || matrix.decimals == '18' && ' with custom gas token (18 decimals)' || '' }}
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false # runs all tests to completion even if one fails
       matrix:
-        node-version: [18, 20]
-        orbit-test: ['0', '1']
-        custom-fee: ['0']
         include:
+          - orbit-test: '0'
+            node-version: 18
+          - orbit-test: '0'
+            node-version: 20
+
+          - orbit-test: '1'
+            node-version: 18
+          - orbit-test: '1'
+            node-version: 20
+
+          - orbit-test: '1'
+            decimals: 16
+            node-version: 18
+          - orbit-test: '1'
+            decimals: 16
+            node-version: 20
+
+          - orbit-test: '1'
+            decimals: 18
+            node-version: 18
+          - orbit-test: '1'
+            decimals: 18
+            node-version: 20
+
           - orbit-test: '1'
-            custom-fee: '1'
+            decimals: 20
             node-version: 18
           - orbit-test: '1'
-            custom-fee: '1'
+            decimals: 20
             node-version: 20
 
     needs: install
     env:
       ORBIT_TEST: ${{ matrix.orbit-test }}
+      DECIMALS: ${{ matrix.decimals || '18' }}
     steps:
       - name: Checkout
         uses: actions/checkout@v3
@@ -158,9 +180,9 @@ jobs:
       - name: Set up the local node
         uses: OffchainLabs/actions/run-nitro-test-node@main
         with:
-          nitro-testnode-ref: ed3cda65c4723b58a2f8be0fbc0c41f4ff2609cd
+          nitro-testnode-ref: adapt-bridge-amount
           l3-node: ${{ matrix.orbit-test == '1' }}
-          args: ${{ matrix.custom-fee == '1' && '--l3-fee-token' || '' }}
+          args: ${{ matrix.decimals == 16 && '--l3-fee-token --l3-fee-token-decimals 16' || matrix.decimals == 20 && '--l3-fee-token --l3-fee-token-decimals 20' || matrix.decimals == 18 && '--l3-fee-token' || '' }}
 
       - name: Copy .env
         run: cp ./.env-sample ./.env

src/lib/assetBridger/erc20Bridger.ts

@@ -71,7 +71,11 @@ import { OmitTyped, RequiredPick } from '../utils/types'
 import { RetryableDataTools } from '../dataEntities/retryableData'
 import { EventArgs } from '../dataEntities/event'
 import { L1ToL2MessageGasParams } from '../message/L1ToL2MessageCreator'
-import { isArbitrumChain } from '../utils/lib'
+import {
+  getNativeTokenDecimals,
+  isArbitrumChain,
+  scaleToNativeTokenDecimals,
+} from '../utils/lib'
 import { L2ERC20Gateway__factory } from '../abi/factories/L2ERC20Gateway__factory'
 
 export interface TokenApproveParams {
@@ -580,7 +584,8 @@ export class Erc20Bridger extends AssetBridger<
    * @returns
    */
   private getDepositRequestOutboundTransferInnerData(
-    depositParams: OmitTyped<L1ToL2MessageGasParams, 'deposit'>
+    depositParams: OmitTyped<L1ToL2MessageGasParams, 'deposit'>,
+    decimals: number
   ) {
     if (!this.nativeTokenIsEth) {
       return defaultAbiCoder.encode(
@@ -591,9 +596,12 @@ export class Erc20Bridger extends AssetBridger<
           // callHookData
           '0x',
           // nativeTokenTotalFee
-          depositParams.gasLimit
-            .mul(depositParams.maxFeePerGas)
-            .add(depositParams.maxSubmissionCost), // will be zero
+          scaleToNativeTokenDecimals({
+            amount: depositParams.gasLimit
+              .mul(depositParams.maxFeePerGas)
+              .add(depositParams.maxSubmissionCost), // will be zero
+            decimals,
+          }),
         ]
       )
     }
@@ -645,15 +653,22 @@ export class Erc20Bridger extends AssetBridger<
       }
     }
 
+    const decimals = await getNativeTokenDecimals({
+      l1Provider,
+      l2Network: this.l2Network,
+    })
+
     const depositFunc = (
       depositParams: OmitTyped<L1ToL2MessageGasParams, 'deposit'>
     ) => {
       depositParams.maxSubmissionCost =
         params.maxSubmissionCost || depositParams.maxSubmissionCost
 
       const iGatewayRouter = L1GatewayRouter__factory.createInterface()
-      const innerData =
-        this.getDepositRequestOutboundTransferInnerData(depositParams)
+      const innerData = this.getDepositRequestOutboundTransferInnerData(
+        depositParams,
+        decimals
+      )
 
       const functionData =
         defaultedParams.excessFeeRefundAddress !== defaultedParams.from
@@ -1019,6 +1034,11 @@ export class AdminErc20Bridger extends Erc20Bridger {
       )
     }
 
+    const nativeTokenDecimals = await getNativeTokenDecimals({
+      l1Provider,
+      l2Network: this.l2Network,
+    })
+
     type GasParams = {
       maxSubmissionCost: BigNumber
       gasLimit: BigNumber
@@ -1051,14 +1071,22 @@ export class AdminErc20Bridger extends Erc20Bridger {
         setTokenGas.gasLimit,
         setGatewayGas.gasLimit,
         doubleFeePerGas,
-        setTokenDeposit,
-        setGatewayDeposit,
+        scaleToNativeTokenDecimals({
+          amount: setTokenDeposit,
+          decimals: nativeTokenDecimals,
+        }),
+        scaleToNativeTokenDecimals({
+          amount: setGatewayDeposit,
+          decimals: nativeTokenDecimals,
+        }),
         l1SenderAddress,
       ])
 
       return {
         data,
-        value: setTokenDeposit.add(setGatewayDeposit),
+        value: this.nativeTokenIsEth
+          ? setTokenDeposit.add(setGatewayDeposit)
+          : BigNumber.from(0),
         to: l1Token.address,
         from,
       }

src/lib/assetBridger/ethBridger.ts

@@ -48,7 +48,11 @@ import { SignerProviderUtils } from '../dataEntities/signerOrProvider'
 import { MissingProviderArbSdkError } from '../dataEntities/errors'
 import { getL2Network } from '../dataEntities/networks'
 import { ERC20__factory } from '../abi/factories/ERC20__factory'
-import { isArbitrumChain } from '../utils/lib'
+import {
+  getNativeTokenDecimals,
+  isArbitrumChain,
+  nativeTokenDecimalsTo18Decimals,
+} from '../utils/lib'
 
 export type ApproveGasTokenParams = {
   /**
@@ -312,10 +316,20 @@ export class EthBridger extends AssetBridger<
   public async getDepositToRequest(
     params: EthDepositToRequestParams
   ): Promise<L1ToL2TransactionRequest> {
+    const decimals = await getNativeTokenDecimals({
+      l1Provider: params.l1Provider,
+      l2Network: this.l2Network,
+    })
+
+    const amountToBeMintedOnChildChain = nativeTokenDecimalsTo18Decimals({
+      amount: params.amount,
+      decimals,
+    })
+
     const requestParams = {
       ...params,
       to: params.destinationAddress,
-      l2CallValue: params.amount,
+      l2CallValue: amountToBeMintedOnChildChain,
       callValueRefundAddress: params.destinationAddress,
       data: '0x',
     }

src/lib/message/L1ToL2MessageGasEstimator.ts

@@ -11,7 +11,12 @@ import {
   RetryableDataTools,
 } from '../dataEntities/retryableData'
 import { L1ToL2TransactionRequest } from '../dataEntities/transactionRequest'
-import { getBaseFee, isDefined } from '../utils/lib'
+import {
+  getBaseFee,
+  getNativeTokenDecimals,
+  isDefined,
+  scaleToNativeTokenDecimals,
+} from '../utils/lib'
 import { OmitTyped } from '../utils/types'
 import {
   L1ToL2MessageGasParams,
@@ -220,7 +225,10 @@ export class L1ToL2MessageGasEstimator {
     const { data } = retryableEstimateData
     const gasLimitDefaults = this.applyGasLimitDefaults(options?.gasLimit)
 
-    // estimate the l2 gas price
+    const l2Network = await getL2Network(this.l2Provider)
+    const decimals = await getNativeTokenDecimals({ l1Provider, l2Network })
+
+    // estimate the l1 gas price
     const maxFeePerGasPromise = this.estimateMaxFeePerGas(options?.maxFeePerGas)
 
     // estimate the submission fee
@@ -254,10 +262,13 @@ export class L1ToL2MessageGasEstimator {
 
     const deposit =
       options?.deposit?.base ||
-      gasLimit
-        .mul(maxFeePerGas)
-        .add(maxSubmissionFee)
-        .add(retryableEstimateData.l2CallValue)
+      scaleToNativeTokenDecimals({
+        amount: gasLimit
+          .mul(maxFeePerGas)
+          .add(maxSubmissionFee)
+          .add(retryableEstimateData.l2CallValue),
+        decimals,
+      })
 
     return {
       gasLimit,

src/lib/utils/lib.ts

@@ -1,11 +1,12 @@
+import { BigNumber, constants } from 'ethers'
 import { Provider } from '@ethersproject/abstract-provider'
 import { TransactionReceipt, JsonRpcProvider } from '@ethersproject/providers'
 import { ArbSdkError } from '../dataEntities/errors'
 import { ArbitrumProvider } from './arbProvider'
-import { l2Networks } from '../dataEntities/networks'
+import { L2Network, l2Networks } from '../dataEntities/networks'
 import { ArbSys__factory } from '../abi/factories/ArbSys__factory'
 import { ARB_SYS_ADDRESS } from '../dataEntities/constants'
-import { BigNumber } from 'ethers'
+import { ERC20__factory } from '../abi/factories/ERC20__factory'
 
 export const wait = (ms: number): Promise<void> =>
   new Promise(res => setTimeout(res, ms))
@@ -195,3 +196,75 @@ export const getBlockRangesForL1Block = async (
 
   return [result[0], props.maxL2Block]
 }
+
+export async function getNativeTokenDecimals({
+  l1Provider,
+  l2Network,
+}: {
+  l1Provider: Provider
+  l2Network: L2Network
+}) {
+  const nativeTokenAddress = l2Network.nativeToken
+
+  if (!nativeTokenAddress || nativeTokenAddress === constants.AddressZero) {
+    return 18
+  }
+
+  const nativeTokenContract = ERC20__factory.connect(
+    nativeTokenAddress,
+    l1Provider
+  )
+
+  try {
+    return await nativeTokenContract.decimals()
+  } catch {
+    return 0
+  }
+}
+
+export function scaleToNativeTokenDecimals({
+  amount,
+  decimals,
+}: {
+  amount: BigNumber
+  decimals: number
+}) {
+  // do nothing for 18 decimals
+  if (decimals === 18) {
+    return amount
+  }
+
+  if (decimals < 18) {
+    const scaledAmount = amount.div(
+      BigNumber.from(10).pow(BigNumber.from(18 - decimals))
+    )
+    // round up if necessary
+    if (
+      scaledAmount
+        .mul(BigNumber.from(10).pow(BigNumber.from(18 - decimals)))
+        .lt(amount)
+    ) {
+      return scaledAmount.add(BigNumber.from(1))
+    }
+    return scaledAmount
+  }
+
+  // decimals > 18
+  return amount.mul(BigNumber.from(10).pow(BigNumber.from(decimals - 18)))
+}
+
+export function nativeTokenDecimalsTo18Decimals({
+  amount,
+  decimals,
+}: {
+  amount: BigNumber
+  decimals: number
+}) {
+  if (decimals < 18) {
+    return amount.mul(BigNumber.from(10).pow(18 - decimals))
+  } else if (decimals > 18) {
+    return amount.div(BigNumber.from(10).pow(decimals - 18))
+  }
+
+  return amount
+}

tests/integration/custom-fee-token/customFeeTokenEthBridger.test.ts

@@ -20,7 +20,7 @@ import { expect } from 'chai'
 import { ethers, constants, Wallet } from 'ethers'
 import dotenv from 'dotenv'
 
-import { parseEther } from '@ethersproject/units'
+import { parseEther, parseUnits } from '@ethersproject/units'
 
 import {
   fundL1 as fundL1Ether,
@@ -30,6 +30,7 @@ import {
 } from '../testHelpers'
 import { L2ToL1Message, L2ToL1MessageStatus } from '../../../src'
 import { describeOnlyWhenCustomGasToken } from './mochaExtensions'
+import { getNativeTokenDecimals } from '../../../src/lib/utils/lib'
 
 dotenv.config()
 
@@ -48,8 +49,15 @@ describeOnlyWhenCustomGasToken(
     })
 
     it('approves the custom fee token to be spent by the Inbox on the parent chain (arbitrary amount, using params)', async function () {
-      const { ethBridger, nativeTokenContract, l1Signer } = await testSetup()
-      const amount = ethers.utils.parseEther('1')
+      const {
+        ethBridger,
+        nativeTokenContract,
+        l1Signer,
+        l1Provider,
+        l2Network,
+      } = await testSetup()
+      const decimals = await getNativeTokenDecimals({ l1Provider, l2Network })
+      const amount = ethers.utils.parseUnits('1', decimals)
 
       await fundL1Ether(l1Signer)
       await fundL1CustomFeeToken(l1Signer)
@@ -158,11 +166,17 @@ describeOnlyWhenCustomGasToken(
         l1Provider,
         l2Signer,
         l2Provider,
+        l2Network,
         ethBridger,
         nativeTokenContract,
       } = await testSetup()
+      const decimals = await getNativeTokenDecimals({
+        l1Provider,
+        l2Network,
+      })
+
       const bridge = ethBridger.l2Network.ethBridge.bridge
-      const amount = parseEther('0.2')
+      const amount = parseUnits('0.2', decimals)
 
       await fundL1Ether(l1Signer)
       await fundL2CustomFeeToken(l2Signer)