fix: stale data edge cases (#3657)

* fix: stale chain block

* chore: simplify atom usage

* fix: support single-token chain

* fix: avoid extra rpcs

* chore: rename isDisabled

* fix: simplify useUSDCPrice

* fix: simplify useComputeSwapInfo

* chore: include type

* fix: guard hasAmounts

src/hooks/useAutoSlippageTolerance.ts

@@ -41,7 +41,7 @@ export default function useAutoSlippageTolerance(
 
   const gasEstimate = guesstimateGas(trade)
   const nativeCurrency = useNativeCurrency()
-  const nativeCurrencyPrice = useUSDCPrice(nativeCurrency ?? undefined)
+  const nativeCurrencyPrice = useUSDCPrice((trade && nativeCurrency) ?? undefined)
 
   return useMemo(() => {
     if (!trade || onL2) return ONE_TENTHS_PERCENT

src/lib/components/Swap/index.tsx

@@ -8,10 +8,10 @@ import { usePendingTransactions } from 'lib/hooks/transactions'
 import useActiveWeb3React from 'lib/hooks/useActiveWeb3React'
 import useHasFocus from 'lib/hooks/useHasFocus'
 import useOnSupportedNetwork from 'lib/hooks/useOnSupportedNetwork'
-import useTokenList, { useSyncTokenList } from 'lib/hooks/useTokenList'
+import { useSyncTokenList } from 'lib/hooks/useTokenList'
 import { displayTxHashAtom } from 'lib/state/swap'
 import { SwapTransactionInfo, Transaction, TransactionType, WrapTransactionInfo } from 'lib/state/transactions'
-import { useMemo, useState } from 'react'
+import { useState } from 'react'
 
 import Dialog from '../Dialog'
 import Header from '../Header'
@@ -63,32 +63,26 @@ export default function Swap(props: SwapProps) {
   const pendingTxs = usePendingTransactions()
   const displayTx = getTransactionFromMap(pendingTxs, displayTxHash)
 
-  const tokenList = useTokenList()
   const onSupportedNetwork = useOnSupportedNetwork()
-  const isSwapSupported = useMemo(
-    () => Boolean(active && onSupportedNetwork && tokenList?.length),
-    [active, onSupportedNetwork, tokenList?.length]
-  )
+  const isDisabled = !(active && onSupportedNetwork)
 
   const focused = useHasFocus(wrapper)
 
-  const isInteractive = Boolean(active && onSupportedNetwork)
-
   return (
     <>
       <SwapPropValidator {...props} />
-      <Updaters {...props} disabled={!isSwapSupported} />
+      <Updaters {...props} disabled={isDisabled} />
       <Header title={<Trans>Swap</Trans>}>
         {active && <Wallet disabled={!account} onClick={props.onConnectWallet} />}
-        <Settings disabled={!isInteractive} />
+        <Settings disabled={isDisabled} />
       </Header>
       <div ref={setWrapper}>
         <BoundaryProvider value={wrapper}>
-          <Input disabled={!isInteractive} focused={focused} />
-          <ReverseButton disabled={!isInteractive} />
-          <Output disabled={!isInteractive} focused={focused}>
+          <Input disabled={isDisabled} focused={focused} />
+          <ReverseButton disabled={isDisabled} />
+          <Output disabled={isDisabled} focused={focused}>
             <Toolbar disabled={!active} />
-            <SwapButton disabled={!isSwapSupported} />
+            <SwapButton disabled={isDisabled} />
           </Output>
         </BoundaryProvider>
       </div>

src/lib/hooks/swap/useSwapInfo.tsx

@@ -43,10 +43,11 @@ function useComputeSwapInfo(): SwapInfo {
     () => tryParseCurrencyAmount(amount, (isExactIn ? currencyIn : currencyOut) ?? undefined),
     [amount, isExactIn, currencyIn, currencyOut]
   )
+  const hasAmounts = currencyIn && currencyOut && parsedAmount
   const trade = useBestTrade(
     isExactIn ? TradeType.EXACT_INPUT : TradeType.EXACT_OUTPUT,
-    parsedAmount,
-    (isExactIn ? currencyOut : currencyIn) ?? undefined
+    hasAmounts ? parsedAmount : undefined,
+    hasAmounts ? (isExactIn ? currencyOut : currencyIn) : undefined
   )
 
   const amountIn = useMemo(
@@ -111,7 +112,7 @@ const swapInfoAtom = atom<SwapInfo>({
 export function SwapInfoUpdater() {
   const setSwapInfo = useUpdateAtom(swapInfoAtom)
   const swapInfo = useComputeSwapInfo()
-  useEffect(() => setSwapInfo(swapInfo), [swapInfo, setSwapInfo])
+  useEffect(() => setSwapInfo(swapInfo), [setSwapInfo, swapInfo])
   return null
 }
 

src/lib/hooks/useBlockNumber.ts

@@ -1,32 +1,38 @@
 import useActiveWeb3React from 'hooks/useActiveWeb3React'
-import useDebounce from 'hooks/useDebounce'
 import useIsWindowVisible from 'hooks/useIsWindowVisible'
 import { atom } from 'jotai'
 import { useAtomValue, useUpdateAtom } from 'jotai/utils'
-import { useCallback, useEffect, useState } from 'react'
+import { useCallback, useEffect } from 'react'
 
-function useBlock() {
+interface ChainBlock {
+  chainId?: number
+  block?: number
+}
+const chainBlockAtom = atom<ChainBlock>({})
+
+function useUpdateChainBlock() {
   const { chainId, library } = useActiveWeb3React()
   const windowVisible = useIsWindowVisible()
-  const [state, setState] = useState<{ chainId?: number; block?: number }>({ chainId })
+  const setChainBlock = useUpdateAtom(chainBlockAtom)
 
   const onBlock = useCallback(
     (block: number) => {
-      setState((state) => {
-        if (state.chainId === chainId) {
-          if (typeof state.block !== 'number') return { chainId, block }
-          return { chainId, block: Math.max(block, state.block) }
+      setChainBlock((chainBlock) => {
+        if (chainBlock.chainId === chainId) {
+          if (chainBlock.block === block) return chainBlock
+          if (typeof chainBlock.block !== 'number') return { chainId, block }
+          return { chainId, block: Math.max(block, chainBlock.block) }
         }
-        return state
+        return chainBlock
       })
     },
-    [chainId]
+    [chainId, setChainBlock]
   )
 
   useEffect(() => {
     if (library && chainId && windowVisible) {
       // If chainId hasn't changed, don't clear the block. This prevents re-fetching still valid data.
-      setState((state) => (state.chainId === chainId ? state : { chainId }))
+      setChainBlock((chainBlock) => (chainBlock.chainId === chainId ? chainBlock : { chainId }))
 
       library
         .getBlockNumber()
@@ -41,30 +47,23 @@ function useBlock() {
       }
     }
     return undefined
-  }, [chainId, library, onBlock, windowVisible])
-
-  const debouncedBlock = useDebounce(state.block, 100)
-  return state.block ? debouncedBlock : undefined
+  }, [chainId, library, onBlock, setChainBlock, windowVisible])
 }
 
-const blockAtom = atom<number | undefined>(undefined)
-
 export function BlockUpdater() {
-  const setBlock = useUpdateAtom(blockAtom)
-  const block = useBlock()
-  useEffect(() => {
-    setBlock(block)
-  }, [block, setBlock])
+  useUpdateChainBlock()
   return null
 }
 
 /** Requires that BlockUpdater be installed in the DOM tree. */
 export default function useBlockNumber(): number | undefined {
-  const { chainId } = useActiveWeb3React()
-  const block = useAtomValue(blockAtom)
-  return chainId ? block : undefined
+  const { chainId: activeChainId } = useActiveWeb3React()
+  const { chainId, block } = useAtomValue(chainBlockAtom)
+  return activeChainId === chainId ? block : undefined
 }
 
 export function useFastForwardBlockNumber(): (block: number) => void {
-  return useUpdateAtom(blockAtom)
+  const { chainId } = useActiveWeb3React()
+  const setChainBlock = useUpdateAtom(chainBlockAtom)
+  return useCallback((block: number) => setChainBlock({ chainId, block }), [chainId, setChainBlock])
 }

src/lib/state/multicall.tsx

@@ -11,8 +11,8 @@ export const store = createStore(reducer)
 export default multicall
 
 export function MulticallUpdater() {
-  const latestBlockNumber = useBlockNumber()
   const { chainId } = useActiveWeb3React()
+  const latestBlockNumber = useBlockNumber()
   const contract = useInterfaceMulticall()
   return <multicall.Updater chainId={chainId} latestBlockNumber={latestBlockNumber} contract={contract} />
 }