use multicall2

src/constants/index.ts

@@ -10,7 +10,7 @@ import COINBASE_ICON_URL from '../assets/images/coinbaseWalletIcon.svg'
 import FORTMATIC_ICON_URL from '../assets/images/fortmaticIcon.png'
 import PORTIS_ICON_URL from '../assets/images/portisIcon.png'
 
-export const MULTICALL_ADDRESSES: { [chainId in ChainId]: string } = {
+export const MULTICALL2_ADDRESSES: { [chainId in ChainId]: string } = {
   [ChainId.MAINNET]: '',
   [ChainId.ROPSTEN]: '0x5BA1e12693Dc8F9c48aAD8770482f4739bEeD696',
   [ChainId.KOVAN]: '0x5BA1e12693Dc8F9c48aAD8770482f4739bEeD696',

src/hooks/useContract.ts

@@ -26,7 +26,7 @@ import {
   MERKLE_DISTRIBUTOR_ADDRESS,
   V1_MIGRATOR_ADDRESS,
   UNI,
-  MULTICALL_ADDRESSES,
+  MULTICALL2_ADDRESSES,
 } from 'constants/index'
 import { abi as NFTPositionManagerABI } from '@uniswap/v3-periphery/artifacts/contracts/NonfungiblePositionManager.sol/NonfungiblePositionManager.json'
 import {
@@ -40,6 +40,7 @@ import { TickLens, UniswapV3Factory, UniswapV3Pool } from 'types/v3'
 import { NonfungiblePositionManager } from 'types/v3/NonfungiblePositionManager'
 import { V3Migrator } from 'types/v3/V3Migrator'
 import { getContract } from 'utils'
+import { Multicall2 } from '../abis/types'
 import { useActiveWeb3React } from './index'
 
 // returns null on errors
@@ -113,9 +114,9 @@ export function usePairContract(pairAddress?: string, withSignerIfPossible?: boo
   return useContract(pairAddress, IUniswapV2PairABI, withSignerIfPossible)
 }
 
-export function useMulticallContract(): Contract | null {
+export function useMulticall2Contract(): Multicall2 | null {
   const { chainId } = useActiveWeb3React()
-  return useContract(chainId && MULTICALL_ADDRESSES[chainId], MULTICALL_ABI, false)
+  return useContract(chainId && MULTICALL2_ADDRESSES[chainId], MULTICALL_ABI, false) as Multicall2
 }
 
 export function useMerkleDistributorContract(): Contract | null {

src/hooks/useCurrentBlockTimestamp.ts

 import { BigNumber } from 'ethers'
 import { useSingleCallResult } from '../state/multicall/hooks'
-import { useMulticallContract } from './useContract'
+import { useMulticall2Contract } from './useContract'
 
 // gets the current timestamp from the blockchain
 export default function useCurrentBlockTimestamp(): BigNumber | undefined {
-  const multicall = useMulticallContract()
+  const multicall = useMulticall2Contract()
   return useSingleCallResult(multicall, 'getCurrentBlockTimestamp')?.result?.[0]
 }

src/hooks/useV3Positions.ts

@@ -69,13 +69,13 @@ export function useV3Positions(account: string | null | undefined): UseV3Positio
   const positionManager = useV3NFTPositionManagerContract()
 
   const { loading: balanceLoading, error: balanceError, result: balanceResult } = useSingleCallResult(
-    positionManager ?? undefined,
+    positionManager,
     'balanceOf',
     [account ?? undefined]
   )
 
   // we don't expect any account balance to ever exceed the bounds of max safe int
-  const accountBalance: number | undefined = balanceResult?.[0] ? Number.parseInt(balanceResult[0]) : undefined
+  const accountBalance: number | undefined = balanceResult?.[0]?.toNumber()
 
   const tokenIdsArgs = useMemo(() => {
     if (accountBalance && account) {
@@ -88,11 +88,7 @@ export function useV3Positions(account: string | null | undefined): UseV3Positio
     return []
   }, [account, accountBalance])
 
-  const tokenIdResults = useSingleContractMultipleData(
-    positionManager ?? undefined,
-    'tokenOfOwnerByIndex',
-    tokenIdsArgs
-  )
+  const tokenIdResults = useSingleContractMultipleData(positionManager, 'tokenOfOwnerByIndex', tokenIdsArgs)
 
   const tokenIds = useMemo(() => {
     if (account) {

src/pages/Pool/index.tsx

@@ -73,6 +73,7 @@ const ResponsiveButtonPrimary = styled(ButtonPrimary)`
     width: 49%;
   `};
 `
+
 const MainContentWrapper = styled.main`
   background-color: ${({ theme }) => theme.bg0};
   padding: 16px;
@@ -80,17 +81,14 @@ const MainContentWrapper = styled.main`
   display: flex;
   flex-direction: column;
 `
+
 export default function Pool() {
   const { account } = useActiveWeb3React()
   const toggleWalletModal = useWalletModalToggle()
   const { t } = useTranslation()
   const theme = useContext(ThemeContext)
 
-  const { error, positions } = useV3Positions(account)
-
-  if (error) {
-    console.error('error fetching v3 positions', error)
-  }
+  const { positions } = useV3Positions(account)
 
   const hasPositions = useMemo(() => Boolean(positions && positions.length > 0), [positions])
 
@@ -131,6 +129,7 @@ export default function Pool() {
       external: false,
     })
   }
+
   return (
     <>
       <PageWrapper>

src/state/multicall/updater.tsx

-import { Contract } from '@ethersproject/contracts'
+import { BigNumber } from 'ethers'
 import { useEffect, useMemo, useRef } from 'react'
 import { useDispatch, useSelector } from 'react-redux'
+import { Multicall2 } from '../../abis/types'
 import { useActiveWeb3React } from '../../hooks'
-import { useMulticallContract } from '../../hooks/useContract'
+import { useMulticall2Contract } from '../../hooks/useContract'
 import useDebounce from '../../hooks/useDebounce'
 import chunkArray from '../../utils/chunkArray'
 import { CancelledError, retry, RetryableError } from '../../utils/retry'
@@ -18,20 +19,24 @@ import {
 
 /**
  * Fetches a chunk of calls, enforcing a minimum block number constraint
- * @param multicallContract multicall contract to fetch against
+ * @param multicall2Contract multicall contract to fetch against
  * @param chunk chunk of calls to make
  * @param minBlockNumber minimum block number of the result set
  */
 async function fetchChunk(
-  multicallContract: Contract,
+  multicall2Contract: Multicall2,
   chunk: Call[],
   minBlockNumber: number
-): Promise<{ results: string[]; blockNumber: number }> {
-  console.debug('Fetching chunk', multicallContract, chunk, minBlockNumber)
-  let resultsBlockNumber, returnData
+): Promise<{
+  results: { success: boolean; returnData: string }[]
+  blockNumber: number
+}> {
+  console.debug('Fetching chunk', multicall2Contract, chunk, minBlockNumber)
+  let resultsBlockNumber: BigNumber
+  let results: { success: boolean; returnData: string }[]
   try {
-    ;[resultsBlockNumber, returnData] = await multicallContract.callStatic.aggregate(
-      chunk.map((obj) => [obj.address, obj.callData])
+    ;[resultsBlockNumber, , results] = await multicall2Contract.callStatic.blockAndAggregate(
+      chunk.map((obj) => ({ target: obj.address, callData: obj.callData }))
     )
   } catch (error) {
     console.debug('Failed to fetch chunk inside retry', error)
@@ -41,7 +46,7 @@ async function fetchChunk(
     console.debug(`Fetched results for old block number: ${resultsBlockNumber.toString()} vs. ${minBlockNumber}`)
     throw new RetryableError('Fetched for old block number')
   }
-  return { results: returnData, blockNumber: resultsBlockNumber.toNumber() }
+  return { results, blockNumber: resultsBlockNumber.toNumber() }
 }
 
 /**
@@ -116,7 +121,7 @@ export default function Updater(): null {
   const debouncedListeners = useDebounce(state.callListeners, 100)
   const latestBlockNumber = useBlockNumber()
   const { chainId } = useActiveWeb3React()
-  const multicallContract = useMulticallContract()
+  const multicall2Contract = useMulticall2Contract()
   const cancellations = useRef<{ blockNumber: number; cancellations: (() => void)[] }>()
 
   const listeningKeys: { [callKey: string]: number } = useMemo(() => {
@@ -132,7 +137,7 @@ export default function Updater(): null {
   ])
 
   useEffect(() => {
-    if (!latestBlockNumber || !chainId || !multicallContract) return
+    if (!latestBlockNumber || !chainId || !multicall2Contract) return
 
     const outdatedCallKeys: string[] = JSON.parse(serializedOutdatedCallKeys)
     if (outdatedCallKeys.length === 0) return
@@ -155,7 +160,7 @@ export default function Updater(): null {
     cancellations.current = {
       blockNumber: latestBlockNumber,
       cancellations: chunkedCalls.map((chunk, index) => {
-        const { cancel, promise } = retry(() => fetchChunk(multicallContract, chunk, latestBlockNumber), {
+        const { cancel, promise } = retry(() => fetchChunk(multicall2Contract, chunk, latestBlockNumber), {
           n: Infinity,
           minWait: 2500,
           maxWait: 3500,
@@ -168,18 +173,29 @@ export default function Updater(): null {
             const firstCallKeyIndex = chunkedCalls.slice(0, index).reduce<number>((memo, curr) => memo + curr.length, 0)
             const lastCallKeyIndex = firstCallKeyIndex + returnData.length
 
+            const slice = outdatedCallKeys.slice(firstCallKeyIndex, lastCallKeyIndex)
+
             dispatch(
               updateMulticallResults({
                 chainId,
-                results: outdatedCallKeys
-                  .slice(firstCallKeyIndex, lastCallKeyIndex)
-                  .reduce<{ [callKey: string]: string | null }>((memo, callKey, i) => {
-                    memo[callKey] = returnData[i] ?? null
-                    return memo
-                  }, {}),
+                results: slice.reduce<{ [callKey: string]: string | null }>((memo, callKey, i) => {
+                  if (returnData[i].success) {
+                    memo[callKey] = returnData[i].returnData ?? null
+                  }
+                  return memo
+                }, {}),
                 blockNumber: fetchBlockNumber,
               })
             )
+
+            // todo: dispatch an error for each call that failed, i.e. returnData[i].success === false
+            // dispatch(
+            //   errorFetchingMulticallResults({
+            //     calls: // todo: compute this,
+            //     chainId,
+            //     fetchingBlockNumber: latestBlockNumber,
+            //   })
+            // )
           })
           .catch((error: any) => {
             if (error instanceof CancelledError) {
@@ -198,7 +214,7 @@ export default function Updater(): null {
         return cancel
       }),
     }
-  }, [chainId, multicallContract, dispatch, serializedOutdatedCallKeys, latestBlockNumber])
+  }, [chainId, multicall2Contract, dispatch, serializedOutdatedCallKeys, latestBlockNumber])
 
   return null
 }

src/state/wallet/hooks.ts

@@ -3,7 +3,7 @@ import { JSBI } from '@uniswap/v2-sdk'
 import { useMemo } from 'react'
 import { useActiveWeb3React } from '../../hooks'
 import { useAllTokens } from '../../hooks/Tokens'
-import { useMulticallContract } from '../../hooks/useContract'
+import { useMulticall2Contract } from '../../hooks/useContract'
 import { isAddress } from '../../utils'
 import { useUserUnclaimedAmount } from '../claim/hooks'
 import { useMultipleContractSingleData, useSingleContractMultipleData } from '../multicall/hooks'
@@ -18,7 +18,7 @@ import { Erc20Interface } from 'abis/types/Erc20'
 export function useETHBalances(
   uncheckedAddresses?: (string | undefined)[]
 ): { [address: string]: CurrencyAmount | undefined } {
-  const multicallContract = useMulticallContract()
+  const multicallContract = useMulticall2Contract()
 
   const addresses: string[] = useMemo(
     () =>