feat: pending approval ui (#3186)

* feat: track approval txs

* refactor: update transactions

* feat: pending approval ui

* chore: fix pending approval doc

* fix: clarify optimized trade

* fix: use relative path for data uri assets

src/constants/chainInfo.ts

-import ethereumLogoUrl from 'assets/images/ethereum-logo.png'
-import arbitrumLogoUrl from 'assets/svg/arbitrum_logo.svg'
-import optimismLogoUrl from 'assets/svg/optimistic_ethereum.svg'
-import polygonMaticLogo from 'assets/svg/polygon-matic-logo.svg'
 import ms from 'ms.macro'
 
+import ethereumLogoUrl from '../assets/images/ethereum-logo.png'
+import arbitrumLogoUrl from '../assets/svg/arbitrum_logo.svg'
+import optimismLogoUrl from '../assets/svg/optimistic_ethereum.svg'
+import polygonMaticLogo from '../assets/svg/polygon-matic-logo.svg'
 import { SupportedChainId, SupportedL1ChainId, SupportedL2ChainId } from './chains'
 import { ARBITRUM_LIST, OPTIMISM_LIST } from './lists'
 

src/lib/components/ActionButton.tsx

-import { AlertTriangle, LargeIcon } from 'lib/icons'
+import { AlertTriangle, Icon, LargeIcon } from 'lib/icons'
 import styled, { Color, css, keyframes, ThemedText } from 'lib/theme'
 import { ReactNode } from 'react'
 
@@ -9,6 +9,10 @@ const StyledButton = styled(Button)`
   border-radius: ${({ theme }) => theme.borderRadius}em;
   flex-grow: 1;
   transition: background-color 0.25s ease-out, flex-grow 0.25s ease-out, padding 0.25s ease-out;
+
+  :disabled {
+    margin: -1px;
+  }
 `
 
 const UpdateRow = styled(Row)``
@@ -24,7 +28,7 @@ const grow = keyframes`
   }
 `
 
-const updatedCss = css`
+const updateCss = css`
   border: 1px solid ${({ theme }) => theme.outline};
   padding: calc(0.25em - 1px);
   padding-left: calc(0.75em - 1px);
@@ -41,19 +45,19 @@ const updatedCss = css`
   }
 `
 
-export const Overlay = styled(Row)<{ updated?: boolean }>`
+export const Overlay = styled(Row)<{ update?: boolean }>`
   border-radius: ${({ theme }) => theme.borderRadius}em;
   flex-direction: row-reverse;
   min-height: 3.5em;
   transition: padding 0.25s ease-out;
 
-  ${({ updated }) => updated && updatedCss}
+  ${({ update }) => update && updateCss}
 `
 
 export interface ActionButtonProps {
   color?: Color
   disabled?: boolean
-  updated?: { message: ReactNode; action: ReactNode }
+  update?: { message: ReactNode; action: ReactNode; icon?: Icon }
   onClick: () => void
   onUpdate?: () => void
   children: ReactNode
@@ -62,22 +66,22 @@ export interface ActionButtonProps {
 export default function ActionButton({
   color = 'accent',
   disabled,
-  updated,
+  update,
   onClick,
   onUpdate,
   children,
 }: ActionButtonProps) {
   return (
-    <Overlay updated={Boolean(updated)} flex align="stretch">
-      <StyledButton color={color} disabled={disabled} onClick={updated ? onUpdate : onClick}>
-        <ThemedText.TransitionButton buttonSize={updated ? 'medium' : 'large'} color="currentColor">
-          {updated ? updated.action : children}
+    <Overlay update={Boolean(update)} flex align="stretch">
+      <StyledButton color={color} disabled={disabled} onClick={update ? onUpdate : onClick}>
+        <ThemedText.TransitionButton buttonSize={update ? 'medium' : 'large'} color="currentColor">
+          {update ? update.action : children}
         </ThemedText.TransitionButton>
       </StyledButton>
-      {updated && (
+      {update && (
         <UpdateRow gap={0.5}>
-          <LargeIcon icon={AlertTriangle} />
-          <ThemedText.Subhead2>{updated?.message}</ThemedText.Subhead2>
+          <LargeIcon color="currentColor" icon={update.icon || AlertTriangle} />
+          <ThemedText.Subhead2>{update?.message}</ThemedText.Subhead2>
         </UpdateRow>
       )}
     </Overlay>

src/lib/components/Swap/Summary/index.tsx

@@ -147,7 +147,7 @@ export function SummaryDialog({ trade, allowedSlippage, onConfirm }: SummaryDial
           <ActionButton
             onClick={onConfirm}
             onUpdate={() => setConfirmedTrade(trade)}
-            updated={doesTradeDiffer ? priceUpdate : undefined}
+            update={doesTradeDiffer ? priceUpdate : undefined}
           >
             <Trans>Confirm swap</Trans>
           </ActionButton>

src/lib/components/Swap/SwapButton.tsx

 import { Trans } from '@lingui/macro'
+import { Token } from '@uniswap/sdk-core'
+import { CHAIN_INFO } from 'constants/chainInfo'
 import { useSwapInfo } from 'lib/hooks/swap'
-import useSwapApproval, { ApprovalState, useSwapApprovalOptimizedTrade } from 'lib/hooks/swap/useSwapApproval'
+import useSwapApproval, {
+  ApprovalState,
+  useSwapApprovalOptimizedTrade,
+  useSwapRouterAddress,
+} from 'lib/hooks/swap/useSwapApproval'
 import { useAddTransaction } from 'lib/hooks/transactions'
-import { useIsPendingApproval } from 'lib/hooks/transactions'
+import { usePendingApproval } from 'lib/hooks/transactions'
+import useActiveWeb3React from 'lib/hooks/useActiveWeb3React'
+import { Link, Spinner } from 'lib/icons'
 import { Field } from 'lib/state/swap'
 import { TransactionType } from 'lib/state/transactions'
+import styled from 'lib/theme'
 import { useCallback, useEffect, useMemo, useState } from 'react'
 
 import ActionButton from '../ActionButton'
 import Dialog from '../Dialog'
+import Row from '../Row'
 import { SummaryDialog } from './Summary'
 
 interface SwapButtonProps {
   disabled?: boolean
 }
 
+const EtherscanA = styled.a`
+  color: currentColor;
+  text-decoration: none;
+`
+
+function useIsPendingApproval(token?: Token, spender?: string): boolean {
+  return Boolean(usePendingApproval(token, spender))
+}
+
 export default function SwapButton({ disabled }: SwapButtonProps) {
+  const { chainId } = useActiveWeb3React()
   const {
     trade,
     allowedSlippage,
+    currencies: { [Field.INPUT]: inputCurrency },
     currencyBalances: { [Field.INPUT]: inputCurrencyBalance },
     currencyAmounts: { [Field.INPUT]: inputCurrencyAmount },
   } = useSwapInfo()
 
-  const [activeTrade, setActiveTrade] = useState<typeof trade.trade | undefined>(undefined)
+  const [activeTrade, setActiveTrade] = useState<typeof trade.trade | undefined>()
   useEffect(() => {
     setActiveTrade((activeTrade) => activeTrade && trade.trade)
   }, [trade])
@@ -33,6 +54,10 @@ export default function SwapButton({ disabled }: SwapButtonProps) {
     // Use trade.trade if there is no swap optimized trade. This occurs if approvals are still pending.
     useSwapApprovalOptimizedTrade(trade.trade, allowedSlippage, useIsPendingApproval) || trade.trade
   const [approval, getApproval] = useSwapApproval(optimizedTrade, allowedSlippage, useIsPendingApproval)
+  const approvalHash = usePendingApproval(
+    inputCurrency?.isToken ? inputCurrency : undefined,
+    useSwapRouterAddress(optimizedTrade)
+  )
 
   const addTransaction = useAddTransaction()
   const addApprovalTransaction = useCallback(() => {
@@ -46,13 +71,27 @@ export default function SwapButton({ disabled }: SwapButtonProps) {
   const actionProps = useMemo(() => {
     if (disabled) return { disabled: true }
 
-    if (inputCurrencyAmount && inputCurrencyBalance?.greaterThan(inputCurrencyAmount)) {
-      // TODO(zzmp): Update UI for pending approvals.
+    if (chainId && inputCurrencyAmount && inputCurrencyBalance?.greaterThan(inputCurrencyAmount)) {
       if (approval === ApprovalState.PENDING) {
-        return { disabled: true }
+        return {
+          disabled: true,
+          update: {
+            message: (
+              <EtherscanA href={approvalHash && `${CHAIN_INFO[chainId].explorer}tx/${approvalHash}`} target="_blank">
+                <Row gap={0.25}>
+                  <Trans>
+                    Approval pending <Link />
+                  </Trans>
+                </Row>
+              </EtherscanA>
+            ),
+            action: <Trans>Approve</Trans>,
+            icon: Spinner,
+          },
+        }
       } else if (approval === ApprovalState.NOT_APPROVED) {
         return {
-          updated: {
+          update: {
             message: <Trans>Approve {inputCurrencyAmount.currency.symbol} first</Trans>,
             action: <Trans>Approve</Trans>,
           },
@@ -62,7 +101,7 @@ export default function SwapButton({ disabled }: SwapButtonProps) {
     }
 
     return { disabled: true }
-  }, [approval, disabled, inputCurrencyAmount, inputCurrencyBalance])
+  }, [approval, approvalHash, chainId, disabled, inputCurrencyAmount, inputCurrencyBalance])
 
   const onConfirm = useCallback(() => {
     // TODO(zzmp): Transact the trade.

src/lib/hooks/swap/useSwapApproval.ts

@@ -34,22 +34,15 @@ function useSwapApprovalStates(
   return useMemo(() => ({ v2, v3, v2V3 }), [v2, v2V3, v3])
 }
 
-// wraps useApproveCallback in the context of a swap
-export default function useSwapApproval(
+export function useSwapRouterAddress(
   trade:
     | V2Trade<Currency, Currency, TradeType>
     | V3Trade<Currency, Currency, TradeType>
     | Trade<Currency, Currency, TradeType>
-    | undefined,
-  allowedSlippage: Percent,
-  useIsPendingApproval: (token?: Token, spender?: string) => boolean
+    | undefined
 ) {
   const { chainId } = useActiveWeb3React()
-  const amountToApprove = useMemo(
-    () => (trade && trade.inputAmount.currency.isToken ? trade.maximumAmountIn(allowedSlippage) : undefined),
-    [trade, allowedSlippage]
-  )
-  const spender = useMemo(
+  return useMemo(
     () =>
       chainId
         ? trade instanceof V2Trade
@@ -60,6 +53,23 @@ export default function useSwapApproval(
         : undefined,
     [chainId, trade]
   )
+}
+
+// wraps useApproveCallback in the context of a swap
+export default function useSwapApproval(
+  trade:
+    | V2Trade<Currency, Currency, TradeType>
+    | V3Trade<Currency, Currency, TradeType>
+    | Trade<Currency, Currency, TradeType>
+    | undefined,
+  allowedSlippage: Percent,
+  useIsPendingApproval: (token?: Token, spender?: string) => boolean
+) {
+  const amountToApprove = useMemo(
+    () => (trade && trade.inputAmount.currency.isToken ? trade.maximumAmountIn(allowedSlippage) : undefined),
+    [trade, allowedSlippage]
+  )
+  const spender = useSwapRouterAddress(trade)
 
   const approval = useApproval(amountToApprove, spender, useIsPendingApproval)
   if (trade instanceof V2Trade || trade instanceof V3Trade) {

src/lib/hooks/transactions/index.tsx

@@ -40,15 +40,16 @@ export function useAddTransaction() {
   )
 }
 
-export function useIsPendingApproval(token?: Token, spender?: string) {
+/** Returns the hash of a pending approval transaction, if it exists. */
+export function usePendingApproval(token?: Token, spender?: string): string | undefined {
   const { chainId } = useActiveWeb3React()
   const txs = useAtomValue(transactionsAtom)
-  if (!chainId || !token || !spender) return false
+  if (!chainId || !token || !spender) return undefined
 
   const chainTxs = txs[chainId]
-  if (!chainTxs) return false
+  if (!chainTxs) return undefined
 
-  return Object.values(chainTxs).some(
+  return Object.values(chainTxs).find(
     (tx) =>
       tx &&
       tx.receipt === undefined &&
@@ -56,7 +57,7 @@ export function useIsPendingApproval(token?: Token, spender?: string) {
       tx.info.tokenAddress === token.address &&
       tx.info.spenderAddress === spender &&
       isTransactionRecent(tx)
-  )
+  )?.info.response.hash
 }
 
 export function TransactionsUpdater() {

src/lib/icons/index.tsx

@@ -11,6 +11,7 @@ import {
   ChevronDown as ChevronDownIcon,
   Clock as ClockIcon,
   CreditCard as CreditCardIcon,
+  ExternalLink as LinkIcon,
   HelpCircle as HelpCircleIcon,
   Info as InfoIcon,
   Settings as SettingsIcon,
@@ -77,6 +78,7 @@ export const Clock = icon(ClockIcon)
 export const CreditCard = icon(CreditCardIcon)
 export const HelpCircle = icon(HelpCircleIcon)
 export const Info = icon(InfoIcon)
+export const Link = icon(LinkIcon)
 export const Settings = icon(SettingsIcon)
 export const Slash = icon(SlashIcon)
 export const Trash2 = icon(Trash2Icon)