fix: update hook deps to improve ref equality checks (#3707)

* fix: prevent unnecessary TokenImg renders

* fix: prevent unnecessary trade renders

src/hooks/useAutoSlippageTolerance.ts

@@ -13,6 +13,7 @@ import useUSDCPrice, { useUSDCValue } from './useUSDCPrice'
 
 const V3_SWAP_DEFAULT_SLIPPAGE = new Percent(50, 10_000) // .50%
 const ONE_TENTHS_PERCENT = new Percent(10, 10_000) // .10%
+export const DEFAULT_AUTO_SLIPPAGE = ONE_TENTHS_PERCENT
 
 /**
  * Return a guess of the gas cost used in computing slippage tolerance for a given trade
@@ -44,7 +45,7 @@ export default function useAutoSlippageTolerance(
   const nativeCurrencyPrice = useUSDCPrice((trade && nativeCurrency) ?? undefined)
 
   return useMemo(() => {
-    if (!trade || onL2) return ONE_TENTHS_PERCENT
+    if (!trade || onL2) return DEFAULT_AUTO_SLIPPAGE
 
     const nativeGasCost =
       nativeGasPrice && typeof gasEstimate === 'number'

src/hooks/useUSDCPrice.ts

 import { Currency, CurrencyAmount, Price, Token, TradeType } from '@uniswap/sdk-core'
 import useActiveWeb3React from 'hooks/useActiveWeb3React'
 import tryParseCurrencyAmount from 'lib/utils/tryParseCurrencyAmount'
-import { useMemo } from 'react'
+import { useMemo, useRef } from 'react'
 
 import { SupportedChainId } from '../constants/chains'
 import { DAI_OPTIMISM, USDC_ARBITRUM, USDC_MAINNET, USDC_POLYGON } from '../constants/tokens'
@@ -32,8 +32,7 @@ export default function useUSDCPrice(currency?: Currency): Price<Currency, Token
     maxHops: 2,
   })
   const v3USDCTrade = useClientSideV3Trade(TradeType.EXACT_OUTPUT, amountOut, currency)
-
-  return useMemo(() => {
+  const price = useMemo(() => {
     if (!currency || !stablecoin) {
       return undefined
     }
@@ -54,6 +53,12 @@ export default function useUSDCPrice(currency?: Currency): Price<Currency, Token
 
     return undefined
   }, [currency, stablecoin, v2USDCTrade, v3USDCTrade.trade])
+
+  const lastPrice = useRef(price)
+  if (!price || !lastPrice.current || !price.equalTo(lastPrice.current)) {
+    lastPrice.current = price
+  }
+  return lastPrice.current
 }
 
 export function useUSDCValue(currencyAmount: CurrencyAmount<Currency> | undefined | null) {

src/lib/components/TokenImg.tsx

@@ -26,16 +26,17 @@ function TokenImg({ token, ...rest }: TokenImgProps) {
     setAttempt((attempt) => ++attempt)
   }, [])
 
-  return useMemo(() => {
+  const src = useMemo(() => {
     // Trigger a re-render when an error occurs.
     void attempt
 
-    const src = srcs.find((src) => !badSrcs.has(src))
+    return srcs.find((src) => !badSrcs.has(src))
+  }, [attempt, srcs])
+
   if (!src) return <MissingToken color="secondary" {...rest} />
 
   const alt = tokenInfo.name || tokenInfo.symbol
   return <img src={src} alt={alt} key={alt} onError={onError} {...rest} />
-  }, [attempt, onError, rest, srcs, tokenInfo.name, tokenInfo.symbol])
 }
 
 export default styled(TokenImg)<{ size?: number }>`

src/lib/hooks/swap/useBestTrade.ts

@@ -6,6 +6,8 @@ import { InterfaceTrade, TradeState } from 'state/routing/types'
 
 import useClientSideSmartOrderRouterTrade from '../routing/useClientSideSmartOrderRouterTrade'
 
+export const INVALID_TRADE = { state: TradeState.INVALID, trade: undefined }
+
 /**
  * Returns the best v2+v3 trade for a desired swap.
  * @param tradeType whether the swap is an exact in/out
@@ -39,6 +41,7 @@ export function useBestTrade(
   return useMemo(() => {
     const { state, trade } = tradeObject
     // If the trade is in a settled state, return it.
+    if (state === TradeState.INVALID) return INVALID_TRADE
     if ((state !== TradeState.LOADING && state !== TradeState.SYNCING) || trade) return tradeObject
 
     const [currencyIn, currencyOut] =

src/lib/hooks/swap/useSwapInfo.tsx

-import { Currency, CurrencyAmount, Percent, TradeType } from '@uniswap/sdk-core'
+import { Currency, CurrencyAmount, TradeType } from '@uniswap/sdk-core'
 import { atom } from 'jotai'
 import { useAtomValue, useUpdateAtom } from 'jotai/utils'
 import useActiveWeb3React from 'lib/hooks/useActiveWeb3React'
 import { useCurrencyBalances } from 'lib/hooks/useCurrencyBalance'
-import useSlippage, { Slippage } from 'lib/hooks/useSlippage'
+import useSlippage, { DEFAULT_SLIPPAGE, Slippage } from 'lib/hooks/useSlippage'
 import useUSDCPriceImpact, { PriceImpact } from 'lib/hooks/useUSDCPriceImpact'
 import { Field, swapAtom } from 'lib/state/swap'
 import tryParseCurrencyAmount from 'lib/utils/tryParseCurrencyAmount'
 import { useEffect, useMemo } from 'react'
 import { InterfaceTrade, TradeState } from 'state/routing/types'
 
-import { useBestTrade } from './useBestTrade'
+import { INVALID_TRADE, useBestTrade } from './useBestTrade'
 import useWrapCallback, { WrapType } from './useWrapCallback'
 
 interface SwapField {
@@ -84,8 +84,8 @@ function useComputeSwapInfo(): SwapInfo {
 const swapInfoAtom = atom<SwapInfo>({
   [Field.INPUT]: {},
   [Field.OUTPUT]: {},
-  trade: { state: TradeState.INVALID },
-  slippage: { auto: true, allowed: new Percent(0) },
+  trade: INVALID_TRADE,
+  slippage: DEFAULT_SLIPPAGE,
 })
 
 export function SwapInfoUpdater() {
@@ -100,17 +100,19 @@ export default function useSwapInfo(): SwapInfo {
   const swapInfo = useAtomValue(swapInfoAtom)
 
   const { [Field.INPUT]: currencyIn, [Field.OUTPUT]: currencyOut } = useAtomValue(swapAtom)
-  const tradeState = useMemo(() => {
-    const { trade } = swapInfo
+  const trade = useMemo(() => {
+    const trade = swapInfo.trade
     if (trade.state === TradeState.VALID && trade.trade) {
-      const isTradeStale =
+      if (
         (currencyIn && !trade.trade.inputAmount.currency.equals(currencyIn)) ||
         (currencyOut && !trade.trade.outputAmount.currency.equals(currencyOut))
+      ) {
         // swapInfo has not yet caught up to swapAtom.
-      if (isTradeStale) return TradeState.LOADING
+        return { ...trade, state: TradeState.LOADING }
       }
-    return trade.state
-  }, [currencyIn, currencyOut, swapInfo])
+    }
+    return trade
+  }, [currencyIn, currencyOut, swapInfo.trade])
 
   const { account } = useActiveWeb3React()
   const [balanceIn, balanceOut] = useCurrencyBalances(
@@ -121,13 +123,16 @@ export default function useSwapInfo(): SwapInfo {
   // swapInfo will lag behind swapAtom by a frame, because its update is triggered by swapAtom
   // so a swap must be marked as loading, with up-to-date currencies, during that update.
   // In other words, swapInfo is derived from swapAtom, so it must be used as the source of truth.
+  const input = useMemo(
+    () => ({ ...swapInfo[Field.INPUT], currency: currencyIn, balance: balanceIn }),
+    [balanceIn, currencyIn, swapInfo]
+  )
+  const output = useMemo(
+    () => ({ ...swapInfo[Field.OUTPUT], currency: currencyOut, balance: balanceOut }),
+    [balanceOut, currencyOut, swapInfo]
+  )
   return useMemo(
-    () => ({
-      ...swapInfo,
-      trade: { ...swapInfo.trade, state: tradeState },
-      [Field.INPUT]: { ...swapInfo[Field.INPUT], currency: currencyIn, balance: balanceIn },
-      [Field.OUTPUT]: { ...swapInfo[Field.OUTPUT], currency: currencyOut, balance: balanceOut },
-    }),
-    [balanceIn, balanceOut, currencyIn, currencyOut, swapInfo, tradeState]
+    () => ({ ...swapInfo, trade, [Field.INPUT]: input, [Field.OUTPUT]: output }),
+    [input, output, swapInfo, trade]
   )
 }

src/lib/hooks/useSlippage.ts

 import { Currency, Percent, TradeType } from '@uniswap/sdk-core'
-import useAutoSlippageTolerance from 'hooks/useAutoSlippageTolerance'
+import useAutoSlippageTolerance, { DEFAULT_AUTO_SLIPPAGE } from 'hooks/useAutoSlippageTolerance'
 import { useAtomValue } from 'jotai/utils'
 import { autoSlippageAtom, maxSlippageAtom } from 'lib/state/settings'
 import { useMemo } from 'react'
@@ -17,6 +17,8 @@ export interface Slippage {
   warning?: 'warning' | 'error'
 }
 
+export const DEFAULT_SLIPPAGE = { auto: true, allowed: DEFAULT_AUTO_SLIPPAGE }
+
 /** Returns the allowed slippage, and whether it is auto-slippage. */
 export default function useSlippage(trade: InterfaceTrade<Currency, Currency, TradeType> | undefined): Slippage {
   const shouldUseAutoSlippage = useAtomValue(autoSlippageAtom)
@@ -27,6 +29,9 @@ export default function useSlippage(trade: InterfaceTrade<Currency, Currency, Tr
     const auto = shouldUseAutoSlippage || !maxSlippage
     const allowed = shouldUseAutoSlippage ? autoSlippage : maxSlippage ?? autoSlippage
     const warning = auto ? undefined : getSlippageWarning(allowed)
+    if (auto && allowed === DEFAULT_AUTO_SLIPPAGE) {
+      return DEFAULT_SLIPPAGE
+    }
     return { auto, allowed, warning }
   }, [autoSlippage, maxSlippage, shouldUseAutoSlippage])
 }