chore: add aaveArbUsdcTokenId to network config

src/earn/poolInfo.test.ts

@@ -1,10 +1,16 @@
 import aavePool from 'src/abis/AavePoolV3'
-import { fetchAavePoolInfo } from 'src/earn/poolInfo'
+import { fetchAavePoolInfo, fetchAavePoolUserBalance } from 'src/earn/poolInfo'
 import { Network } from 'src/transactions/types'
 import { publicClient } from 'src/viem'
 import networkConfig from 'src/web3/networkConfig'
+import { getContract } from 'viem'
 
-describe('poolInfo', () => {
+jest.mock('viem', () => ({
+  ...jest.requireActual('viem'),
+  getContract: jest.fn(),
+}))
+
+describe('fetchAavePoolInfo', () => {
   it('fetches poolInfo from contract', async () => {
     jest.spyOn(publicClient[Network.Arbitrum], 'readContract').mockResolvedValue({
       currentLiquidityRate: BigInt(1e27 * 0.036),
@@ -21,3 +27,38 @@ describe('poolInfo', () => {
     })
   })
 })
+
+describe('fetchAavePoolUserBalance', () => {
+  it('fetches user balance from contract', async () => {
+    const mockReadContract = jest
+      .spyOn(publicClient[Network.Arbitrum], 'readContract')
+      .mockResolvedValue({
+        aTokenAddress: '0xaToken',
+      })
+    const mockContractInstance = {
+      read: {
+        balanceOf: jest.fn().mockResolvedValue(BigInt(10750000)),
+        decimals: jest.fn().mockResolvedValue(6),
+      },
+    }
+
+    // @ts-ignore
+    jest.mocked(getContract).mockReturnValue(mockContractInstance)
+
+    const result = await fetchAavePoolUserBalance({
+      assetAddress: '0x1234',
+      walletAddress: '0x5678',
+    })
+
+    expect(mockReadContract).toHaveBeenCalledWith({
+      abi: aavePool,
+      address: networkConfig.arbAavePoolV3ContractAddress,
+      functionName: 'getReserveData',
+      args: ['0x1234'],
+    })
+
+    expect(mockContractInstance.read.balanceOf).toHaveBeenCalledWith(['0x5678'])
+    expect(mockContractInstance.read.decimals).toHaveBeenCalled()
+    expect(result).toEqual({ balanceInDecimal: '10.75' })
+  })
+})

src/earn/poolInfo.ts

@@ -1,18 +1,22 @@
 import BigNumber from 'bignumber.js'
 import AavePool from 'src/abis/AavePoolV3'
+import erc20 from 'src/abis/IERC20'
 import { Network } from 'src/transactions/types'
 import Logger from 'src/utils/Logger'
 import { ensureError } from 'src/utils/ensureError'
 import { publicClient } from 'src/viem'
 import networkConfig from 'src/web3/networkConfig'
-import { Address } from 'viem'
+import { Address, formatUnits, getContract } from 'viem'
 
 const TAG = 'earn/poolInfo'
 
 const COMPOUND_PERIOD = 365 * 24 * 60 * 60 // 1 year in seconds
 
 export async function fetchAavePoolInfo(assetAddress: Address) {
   try {
+    if (!assetAddress) {
+      throw new Error('No asset address provided')
+    }
     Logger.debug(TAG, 'Fetching Aave pool info for asset', assetAddress)
     const result = await publicClient[Network.Arbitrum].readContract({
       abi: AavePool,
@@ -32,3 +36,47 @@
     throw err
   }
 }
+
+/** @beta - Exclude from Knip dep check */
+export async function fetchAavePoolUserBalance({
+  assetAddress,
+  walletAddress,
+}: {
+  assetAddress: Address
+  walletAddress: Address
+}) {
+  try {
+    if (!assetAddress) {
+      throw new Error('No asset address provided')
+    }
+    if (!walletAddress) {
+      throw new Error('No wallet address provided')
+    }
+    Logger.debug(TAG, 'Fetching Aave pool user balance', { assetAddress, walletAddress })
+    const result = await publicClient[Network.Arbitrum].readContract({
+      abi: AavePool,
+      address: networkConfig.arbAavePoolV3ContractAddress,
+      functionName: 'getReserveData',
+      args: [assetAddress],
+    })
+
+    const { aTokenAddress } = result as { aTokenAddress: Address }
+    const aaveUSDCContract = getContract({
+      abi: erc20.abi,
+      address: aTokenAddress,
+      client: {
+        public: publicClient[Network.Arbitrum],
+      },
+    })
+
+    const balance = await aaveUSDCContract.read.balanceOf([walletAddress])
+    const decimals = await aaveUSDCContract.read.decimals()
+    const balanceInDecimal = formatUnits(balance, decimals)
+
+    return { balanceInDecimal }
+  } catch (error) {
+    const err = ensureError(error)
+    Logger.error(TAG, 'Failed to fetch Aave pool user balance', err)
+    throw err
+  }
+}