Add useSwapsEthToken hook and utilize wherever we need the ETH 'token' for swaps (#9537)

* Add useSwapsEthToken hook and utilize wherever we need the ETH 'token' for swaps
* Remove rawEthTokens param from useTokensToSearch calls

Co-authored-by: Mark Stacey <markjstacey@gmail.com>
Co-authored-by: Erik Marks <rekmarks@protonmail.com>

ui/app/components/app/wallet-overview/eth-overview.js

@@ -8,17 +8,16 @@ import Identicon from '../../ui/identicon'
 import { I18nContext } from '../../../contexts/i18n'
 import { SEND_ROUTE, BUILD_QUOTE_ROUTE } from '../../../helpers/constants/routes'
 import { useMetricEvent, useNewMetricEvent } from '../../../hooks/useMetricEvent'
+import { useSwapsEthToken } from '../../../hooks/useSwapsEthToken'
 import Tooltip from '../../ui/tooltip'
 import UserPreferencedCurrencyDisplay from '../user-preferenced-currency-display'
 import { PRIMARY, SECONDARY } from '../../../helpers/constants/common'
 import { showModal } from '../../../store/actions'
 import { isBalanceCached, getSelectedAccount, getShouldShowFiat, getCurrentNetworkId, getCurrentKeyring } from '../../../selectors/selectors'
-import { getValueFromWeiHex } from '../../../helpers/utils/conversions.util'
 import SwapIcon from '../../ui/icon/swap-icon.component'
 import BuyIcon from '../../ui/icon/overview-buy-icon.component'
 import SendIcon from '../../ui/icon/overview-send-icon.component'
 import { getSwapsFeatureLiveness, setSwapsFromToken } from '../../../ducks/swaps/swaps'
-import { ETH_SWAPS_TOKEN_OBJECT } from '../../../helpers/constants/swaps'
 import IconButton from '../../ui/icon-button'
 import { MAINNET_NETWORK_ID } from '../../../../../app/scripts/controllers/network/enums'
 import WalletOverview from './wallet-overview'
@@ -50,6 +49,7 @@ const EthOverview = ({ className }) => {
   const networkId = useSelector(getCurrentNetworkId)
   const enteredSwapsEvent = useNewMetricEvent({ event: 'Swaps Opened', properties: { source: 'Main View', active_currency: 'ETH' }, category: 'swaps' })
   const swapsEnabled = useSelector(getSwapsFeatureLiveness)
+  const swapsEthToken = useSwapsEthToken()
 
   return (
     <WalletOverview
@@ -118,11 +118,7 @@ const EthOverview = ({ className }) => {
               onClick={() => {
                 if (networkId === MAINNET_NETWORK_ID) {
                   enteredSwapsEvent()
-                  dispatch(setSwapsFromToken({
-                    ...ETH_SWAPS_TOKEN_OBJECT,
-                    balance,
-                    string: getValueFromWeiHex({ value: balance, numberOfDecimals: 4, toDenomination: 'ETH' }),
-                  }))
+                  dispatch(setSwapsFromToken(swapsEthToken))
                   if (usingHardwareWallet) {
                     global.platform.openExtensionInBrowser(BUILD_QUOTE_ROUTE)
                   } else {

ui/app/ducks/swaps/swaps.js

@@ -23,7 +23,7 @@ import {
 import { AWAITING_SWAP_ROUTE, BUILD_QUOTE_ROUTE, LOADING_QUOTES_ROUTE, SWAPS_ERROR_ROUTE, SWAPS_MAINTENANCE_ROUTE } from '../../helpers/constants/routes'
 import { fetchSwapsFeatureLiveness } from '../../pages/swaps/swaps.util'
 import { calcGasTotal } from '../../pages/send/send.utils'
-import { decimalToHex, getValueFromWeiHex, hexMax, decGWEIToHexWEI } from '../../helpers/utils/conversions.util'
+import { decimalToHex, getValueFromWeiHex, hexMax, decGWEIToHexWEI, hexToDecimal } from '../../helpers/utils/conversions.util'
 import { calcTokenAmount } from '../../helpers/utils/token-util'
 import {
   getFastPriceEstimateInHexWEI,
@@ -274,7 +274,7 @@ export const fetchQuotesAndSetQuoteState = (history, inputValue, maxSlippage, me
       {
         ...ETH_SWAPS_TOKEN_OBJECT,
         string: getValueFromWeiHex({ value: selectedAccount.balance, numberOfDecimals: 4, toDenomination: 'ETH' }),
-        balance: selectedAccount.balance,
+        balance: hexToDecimal(selectedAccount.balance),
       } :
       fetchParams?.metaData?.sourceTokenInfo
     const selectedFromToken = getFromToken(state) || fetchParamsFromToken || {}

ui/app/hooks/useSwapsEthToken.js

@@ -0,0 +1,50 @@
+import { useSelector } from 'react-redux'
+import { getSelectedAccount } from '../selectors'
+import { ETH_SWAPS_TOKEN_OBJECT } from '../helpers/constants/swaps'
+import { getValueFromWeiHex, hexToDecimal } from '../helpers/utils/conversions.util'
+
+/**
+ * @typedef {Object} SwapsEthToken
+ * @property {string} symbol - The symbol for ETH, namely "ETH"
+ * @property {string} name - The name of the ETH currency, "Ether"
+ * @property {string} address - A substitute address for the metaswap-api to
+ * recognize the ETH token
+ * @property {string} decimals - The number of ETH decimals, i.e. 18
+ * @property {string} balance - The user's ETH balance in decimal wei, with a
+ * precision of 4 decimal places
+ * @property {string} string - The user's ETH balance in decimal ETH
+ */
+
+/**
+ * Swaps related code uses token objects for various purposes. These objects
+ * always have the following properties: `symbol`, `name`, `address`, and
+ * `decimals`.
+ *
+ * When available for the current account, the objects can have `balance` and
+ * `string` properties.
+ * `balance` is the users token balance in decimal values, denominated in the
+ * minimal token units (according to its decimals).
+ * `string` is the token balance in a readable format, ready for rendering.
+ *
+ * Swaps treats ETH as a token, and we use the ETH_SWAPS_TOKEN_OBJECT constant
+ * to set the standard properties for the token. The useSwapsEthToken hook
+ * extends that object with `balance` and `balance` values of the same type as
+ * in regular ERC-20 token objects, per the above description.
+ *
+ * @returns {SwapsEthToken} The token object representation of the currently
+ * selected account's ETH balance, as expected by the Swaps API.
+ */
+export function useSwapsEthToken () {
+  const selectedAccount = useSelector(getSelectedAccount)
+  const { balance } = selectedAccount
+
+  return {
+    ...ETH_SWAPS_TOKEN_OBJECT,
+    balance: hexToDecimal(balance),
+    string: getValueFromWeiHex({
+      value: balance,
+      numberOfDecimals: 4,
+      toDenomination: 'ETH',
+    }),
+  }
+}

ui/app/hooks/useTokensToSearch.js

@@ -3,12 +3,11 @@ import { useSelector } from 'react-redux'
 import contractMap from 'eth-contract-metadata'
 import BigNumber from 'bignumber.js'
 import { isEqual, shuffle } from 'lodash'
-import { getValueFromWeiHex } from '../helpers/utils/conversions.util'
 import { checksumAddress } from '../helpers/utils/util'
 import { getTokenFiatAmount } from '../helpers/utils/token-util'
 import { getTokenExchangeRates, getConversionRate, getCurrentCurrency } from '../selectors'
 import { getSwapsTokens } from '../ducks/swaps/swaps'
-import { ETH_SWAPS_TOKEN_OBJECT } from '../helpers/constants/swaps'
+import { useSwapsEthToken } from './useSwapsEthToken'
 import { useEqualityCheck } from './useEqualityCheck'
 
 const tokenList = shuffle(Object.entries(contractMap)
@@ -50,7 +49,13 @@ export function getRenderableTokenData (token, contractExchangeRates, conversion
   }
 }
 
-export function useTokensToSearch ({ providedTokens, rawEthBalance, usersTokens = [], topTokens = {}, onlyEth, singleToken }) {
+export function useTokensToSearch ({
+  providedTokens,
+  usersTokens = [],
+  topTokens = {},
+  onlyEth,
+  singleToken,
+}) {
   const tokenConversionRates = useSelector(getTokenExchangeRates, isEqual)
   const conversionRate = useSelector(getConversionRate)
   const currentCurrency = useSelector(getCurrentCurrency)
@@ -58,9 +63,9 @@ export function useTokensToSearch ({ providedTokens, rawEthBalance, usersTokens
   const memoizedTopTokens = useEqualityCheck(topTokens)
   const memoizedUsersToken = useEqualityCheck(usersTokens)
 
-  const decEthBalance = getValueFromWeiHex({ value: rawEthBalance, numberOfDecimals: 4, toDenomination: 'ETH' })
+  const swapsEthToken = useSwapsEthToken()
   const [ethToken] = useState(() => getRenderableTokenData(
-    { ...ETH_SWAPS_TOKEN_OBJECT, balance: rawEthBalance, string: decEthBalance },
+    swapsEthToken,
     tokenConversionRates,
     conversionRate,
     currentCurrency,

ui/app/pages/swaps/build-quote/build-quote.js

@@ -7,6 +7,7 @@ import { useHistory } from 'react-router-dom'
 import { MetaMetricsContext } from '../../../contexts/metametrics.new'
 import { useTokensToSearch } from '../../../hooks/useTokensToSearch'
 import { useEqualityCheck } from '../../../hooks/useEqualityCheck'
+import { useSwapsEthToken } from '../../../hooks/useSwapsEthToken'
 import { I18nContext } from '../../../contexts/i18n'
 import DropdownInputPair from '../dropdown-input-pair'
 import DropdownSearchList from '../dropdown-search-list'
@@ -60,8 +61,9 @@ export default function BuildQuote ({
   const topAssets = useSelector(getTopAssets)
   const fromToken = useSelector(getFromToken)
   const toToken = useSelector(getToToken) || destinationTokenInfo
+  const swapsEthToken = useSwapsEthToken()
   const fetchParamsFromToken = sourceTokenInfo?.symbol === 'ETH'
-    ? { ...ETH_SWAPS_TOKEN_OBJECT, string: getValueFromWeiHex({ value: ethBalance, numberOfDecimals: 4, toDenomination: 'ETH' }), balance: ethBalance }
+    ? swapsEthToken
     : sourceTokenInfo
 
   const { loading, tokensWithBalances } = useTokenTracker(tokens)
@@ -77,14 +79,12 @@ export default function BuildQuote ({
 
   const selectedFromToken = useTokensToSearch({
     providedTokens: fromToken || fetchParamsFromToken ? [fromToken || fetchParamsFromToken] : [],
-    rawEthBalance: ethBalance,
     usersTokens: memoizedUsersTokens,
     onlyEth: (fromToken || fetchParamsFromToken)?.symbol === 'ETH',
     singleToken: true,
   })[0]
 
   const tokensToSearch = useTokensToSearch({
-    rawEthBalance: ethBalance,
     usersTokens: memoizedUsersTokens,
     topTokens: topAssets,
   })

ui/app/pages/swaps/intro-popup/intro-popup.js

@@ -1,27 +1,24 @@
 import React, { useContext } from 'react'
-import { useDispatch, useSelector } from 'react-redux'
+import { useDispatch } from 'react-redux'
 import { useHistory } from 'react-router-dom'
 import PropTypes from 'prop-types'
-import { getValueFromWeiHex } from '../../../helpers/utils/conversions.util'
 import { setSwapsFromToken } from '../../../ducks/swaps/swaps'
-import { ETH_SWAPS_TOKEN_OBJECT } from '../../../helpers/constants/swaps'
 import { I18nContext } from '../../../contexts/i18n'
 import { BUILD_QUOTE_ROUTE } from '../../../helpers/constants/routes'
 import { useNewMetricEvent } from '../../../hooks/useMetricEvent'
+import { useSwapsEthToken } from '../../../hooks/useSwapsEthToken'
 import Button from '../../../components/ui/button'
 import Popover from '../../../components/ui/popover'
-import { getSelectedAccount } from '../../../selectors/selectors'
 
 export default function IntroPopup ({ onClose }) {
   const dispatch = useDispatch(useDispatch)
   const history = useHistory()
   const t = useContext(I18nContext)
-  const selectedAccount = useSelector(getSelectedAccount)
-  const { balance } = selectedAccount
   const enteredSwapsEvent = useNewMetricEvent({ event: 'Swaps Opened', properties: { source: 'Intro popup', active_currency: 'ETH' }, category: 'swaps' })
   const blogPostVisitedEvent = useNewMetricEvent({ event: 'Blog Post Visited ', category: 'swaps' })
   const contractAuditVisitedEvent = useNewMetricEvent({ event: 'Contract Audit Visited', category: 'swaps' })
   const productOverviewDismissedEvent = useNewMetricEvent({ event: 'Product Overview Dismissed', category: 'swaps' })
+  const swapsEthToken = useSwapsEthToken()
 
   return (
     <div className="intro-popup">
@@ -41,11 +38,7 @@ export default function IntroPopup ({ onClose }) {
             onClick={() => {
               onClose()
               enteredSwapsEvent()
-              dispatch(setSwapsFromToken({
-                ...ETH_SWAPS_TOKEN_OBJECT,
-                balance,
-                string: getValueFromWeiHex({ value: balance, numberOfDecimals: 4, toDenomination: 'ETH' }),
-              }))
+              dispatch(setSwapsFromToken(swapsEthToken))
               history.push(BUILD_QUOTE_ROUTE)
             }}
           >

ui/app/pages/swaps/view-quote/view-quote.js

@@ -8,6 +8,7 @@ import { I18nContext } from '../../../contexts/i18n'
 import SelectQuotePopover from '../select-quote-popover'
 import { useEqualityCheck } from '../../../hooks/useEqualityCheck'
 import { useNewMetricEvent } from '../../../hooks/useMetricEvent'
+import { useSwapsEthToken } from '../../../hooks/useSwapsEthToken'
 import { MetaMetricsContext } from '../../../contexts/metametrics.new'
 import FeeCard from '../fee-card'
 import { setCustomGasLimit } from '../../../ducks/gas/gas.duck'
@@ -68,10 +69,7 @@ import { getCustomTxParamsData } from '../../confirm-approve/confirm-approve.uti
 import ActionableMessage from '../actionable-message'
 import { quotesToRenderableData, getRenderableGasFeesForQuote } from '../swaps.util'
 import { useTokenTracker } from '../../../hooks/useTokenTracker'
-import {
-  ETH_SWAPS_TOKEN_OBJECT,
-  QUOTES_EXPIRED_ERROR,
-} from '../../../helpers/constants/swaps'
+import { QUOTES_EXPIRED_ERROR } from '../../../helpers/constants/swaps'
 import CountdownTimer from '../countdown-timer'
 import SwapsFooter from '../swaps-footer'
 
@@ -143,8 +141,9 @@ export default function ViewQuote () {
   const gasTotalInWeiHex = calcGasTotal(maxGasLimit, gasPrice)
 
   const { tokensWithBalances } = useTokenTracker(swapsTokens)
-  const balanceToken = fetchParamsSourceToken === ETH_SWAPS_TOKEN_OBJECT.address
-    ? { ...ETH_SWAPS_TOKEN_OBJECT, balance: ethBalance }
+  const swapsEthToken = useSwapsEthToken()
+  const balanceToken = fetchParamsSourceToken === swapsEthToken.address
+    ? swapsEthToken
     : tokensWithBalances.find(({ address }) => address === fetchParamsSourceToken)
 
   const selectedFromToken = balanceToken || usedQuote.sourceTokenInfo