Routing updates only (#1265)

* start routing fix for multi hops

* switch to input amount comparison on exactOut

* make percent logic more clear

* remove uneeded comaprisons

* move logic to functions for testing

* add multi hop disable switch

* add GA

* fix bug to return multihop no single

* update swap details

* code clean

* routing only

src/components/Settings/index.tsx

@@ -9,7 +9,8 @@ import {
   useDarkModeManager,
   useExpertModeManager,
   useUserTransactionTTL,
-  useUserSlippageTolerance
+  useUserSlippageTolerance,
+  useUserSingleHopOnly
 } from '../../state/user/hooks'
 import { TYPE } from '../../theme'
 import { ButtonError } from '../Button'
@@ -135,6 +136,8 @@ export default function SettingsTab() {
 
   const [expertMode, toggleExpertMode] = useExpertModeManager()
 
+  const [singleHopOnly, setSingleHopOnly] = useUserSingleHopOnly()
+
   const [darkMode, toggleDarkMode] = useDarkModeManager()
 
   // show confirmation view before turning on
@@ -230,6 +233,19 @@ export default function SettingsTab() {
                 }
               />
             </RowBetween>
+            <RowBetween>
+              <RowFixed>
+                <TYPE.black fontWeight={400} fontSize={14} color={theme.text2}>
+                  Disable Multihops
+                </TYPE.black>
+                <QuestionHelper text="Restricts swaps to direct pairs only." />
+              </RowFixed>
+              <Toggle
+                id="toggle-disable-multihop-button"
+                isActive={singleHopOnly}
+                toggle={() => (singleHopOnly ? setSingleHopOnly(false) : setSingleHopOnly(true))}
+              />
+            </RowBetween>
             <RowBetween>
               <RowFixed>
                 <TYPE.black fontWeight={400} fontSize={14} color={theme.text2}>

src/constants/index.ts

@@ -201,6 +201,7 @@ export const BLOCKED_PRICE_IMPACT_NON_EXPERT: Percent = new Percent(JSBI.BigInt(
 // used to ensure the user doesn't send so much ETH so they end up with <.01
 export const MIN_ETH: JSBI = JSBI.exponentiate(JSBI.BigInt(10), JSBI.BigInt(16)) // .01 ETH
 export const BETTER_TRADE_LINK_THRESHOLD = new Percent(JSBI.BigInt(75), JSBI.BigInt(10000))
+export const BETTER_TRADE_LESS_HOPS_THRESHOLD = new Percent(JSBI.BigInt(50), JSBI.BigInt(10000))
 
 // SDN OFAC addresses
 export const BLOCKED_ADDRESSES: string[] = [

src/data/V1.ts

@@ -3,11 +3,9 @@ import {
   BigintIsh,
   Currency,
   CurrencyAmount,
-  currencyEquals,
   ETHER,
   JSBI,
   Pair,
-  Percent,
   Route,
   Token,
   TokenAmount,
@@ -157,31 +155,3 @@ export function useV1TradeExchangeAddress(trade: Trade | undefined): string | un
   }, [trade])
   return useV1ExchangeAddress(tokenAddress)
 }
-
-const ZERO_PERCENT = new Percent('0')
-const ONE_HUNDRED_PERCENT = new Percent('1')
-
-// returns whether tradeB is better than tradeA by at least a threshold percentage amount
-export function isTradeBetter(
-  tradeA: Trade | undefined,
-  tradeB: Trade | undefined,
-  minimumDelta: Percent = ZERO_PERCENT
-): boolean | undefined {
-  if (tradeA && !tradeB) return false
-  if (tradeB && !tradeA) return true
-  if (!tradeA || !tradeB) return undefined
-
-  if (
-    tradeA.tradeType !== tradeB.tradeType ||
-    !currencyEquals(tradeA.inputAmount.currency, tradeB.inputAmount.currency) ||
-    !currencyEquals(tradeB.outputAmount.currency, tradeB.outputAmount.currency)
-  ) {
-    throw new Error('Trades are not comparable')
-  }
-
-  if (minimumDelta.equalTo(ZERO_PERCENT)) {
-    return tradeA.executionPrice.lessThan(tradeB.executionPrice)
-  } else {
-    return tradeA.executionPrice.raw.multiply(minimumDelta.add(ONE_HUNDRED_PERCENT)).lessThan(tradeB.executionPrice)
-  }
-}

src/hooks/Trades.ts

@@ -1,12 +1,14 @@
+import { isTradeBetter } from 'utils/trades'
 import { Currency, CurrencyAmount, Pair, Token, Trade } from '@uniswap/sdk'
 import flatMap from 'lodash.flatmap'
 import { useMemo } from 'react'
 
-import { BASES_TO_CHECK_TRADES_AGAINST, CUSTOM_BASES } from '../constants'
+import { BASES_TO_CHECK_TRADES_AGAINST, CUSTOM_BASES, BETTER_TRADE_LESS_HOPS_THRESHOLD } from '../constants'
 import { PairState, usePairs } from '../data/Reserves'
 import { wrappedCurrency } from '../utils/wrappedCurrency'
 
 import { useActiveWeb3React } from './index'
+import { useUserSingleHopOnly } from 'state/user/hooks'
 
 function useAllCommonPairs(currencyA?: Currency, currencyB?: Currency): Pair[] {
   const { chainId } = useActiveWeb3React()
@@ -78,19 +80,40 @@ function useAllCommonPairs(currencyA?: Currency, currencyB?: Currency): Pair[] {
   )
 }
 
+const MAX_HOPS = 3
+
 /**
  * Returns the best trade for the exact amount of tokens in to the given token out
  */
 export function useTradeExactIn(currencyAmountIn?: CurrencyAmount, currencyOut?: Currency): Trade | null {
   const allowedPairs = useAllCommonPairs(currencyAmountIn?.currency, currencyOut)
+
+  const [singleHopOnly] = useUserSingleHopOnly()
+
   return useMemo(() => {
     if (currencyAmountIn && currencyOut && allowedPairs.length > 0) {
-      return (
-        Trade.bestTradeExactIn(allowedPairs, currencyAmountIn, currencyOut, { maxHops: 3, maxNumResults: 1 })[0] ?? null
-      )
+      if (singleHopOnly) {
+        return (
+          Trade.bestTradeExactIn(allowedPairs, currencyAmountIn, currencyOut, { maxHops: 1, maxNumResults: 1 })[0] ??
+          null
+        )
+      }
+      // search through trades with varying hops, find best trade out of them
+      let bestTradeSoFar: Trade | null = null
+      for (let i = 1; i <= MAX_HOPS; i++) {
+        const currentTrade: Trade | null =
+          Trade.bestTradeExactIn(allowedPairs, currencyAmountIn, currencyOut, { maxHops: i, maxNumResults: 1 })[0] ??
+          null
+        // if current trade is best yet, save it
+        if (isTradeBetter(bestTradeSoFar, currentTrade, BETTER_TRADE_LESS_HOPS_THRESHOLD)) {
+          bestTradeSoFar = currentTrade
+        }
+      }
+      return bestTradeSoFar
     }
+
     return null
-  }, [allowedPairs, currencyAmountIn, currencyOut])
+  }, [allowedPairs, currencyAmountIn, currencyOut, singleHopOnly])
 }
 
 /**
@@ -99,13 +122,28 @@ export function useTradeExactIn(currencyAmountIn?: CurrencyAmount, currencyOut?:
 export function useTradeExactOut(currencyIn?: Currency, currencyAmountOut?: CurrencyAmount): Trade | null {
   const allowedPairs = useAllCommonPairs(currencyIn, currencyAmountOut?.currency)
 
+  const [singleHopOnly] = useUserSingleHopOnly()
+
   return useMemo(() => {
     if (currencyIn && currencyAmountOut && allowedPairs.length > 0) {
-      return (
-        Trade.bestTradeExactOut(allowedPairs, currencyIn, currencyAmountOut, { maxHops: 3, maxNumResults: 1 })[0] ??
-        null
-      )
+      if (singleHopOnly) {
+        return (
+          Trade.bestTradeExactOut(allowedPairs, currencyIn, currencyAmountOut, { maxHops: 1, maxNumResults: 1 })[0] ??
+          null
+        )
+      }
+      // search through trades with varying hops, find best trade out of them
+      let bestTradeSoFar: Trade | null = null
+      for (let i = 1; i <= MAX_HOPS; i++) {
+        const currentTrade =
+          Trade.bestTradeExactOut(allowedPairs, currencyIn, currencyAmountOut, { maxHops: i, maxNumResults: 1 })[0] ??
+          null
+        if (isTradeBetter(bestTradeSoFar, currentTrade, BETTER_TRADE_LESS_HOPS_THRESHOLD)) {
+          bestTradeSoFar = currentTrade
+        }
+      }
+      return bestTradeSoFar
     }
     return null
-  }, [allowedPairs, currencyIn, currencyAmountOut])
+  }, [currencyIn, currencyAmountOut, allowedPairs, singleHopOnly])
 }

src/pages/Swap/index.tsx

@@ -21,7 +21,7 @@ import TokenWarningModal from '../../components/TokenWarningModal'
 import ProgressSteps from '../../components/ProgressSteps'
 
 import { BETTER_TRADE_LINK_THRESHOLD, INITIAL_ALLOWED_SLIPPAGE } from '../../constants'
-import { getTradeVersion, isTradeBetter } from '../../data/V1'
+import { getTradeVersion } from '../../data/V1'
 import { useActiveWeb3React } from '../../hooks'
 import { useCurrency } from '../../hooks/Tokens'
 import { ApprovalState, useApproveCallbackFromTrade } from '../../hooks/useApproveCallback'
@@ -37,13 +37,14 @@ import {
   useSwapActionHandlers,
   useSwapState
 } from '../../state/swap/hooks'
-import { useExpertModeManager, useUserSlippageTolerance } from '../../state/user/hooks'
+import { useExpertModeManager, useUserSlippageTolerance, useUserSingleHopOnly } from '../../state/user/hooks'
 import { LinkStyledButton, TYPE } from '../../theme'
 import { maxAmountSpend } from '../../utils/maxAmountSpend'
 import { computeTradePriceBreakdown, warningSeverity } from '../../utils/prices'
 import AppBody from '../AppBody'
 import { ClickableText } from '../Pool/styleds'
 import Loader from '../../components/Loader'
+import { isTradeBetter } from 'utils/trades'
 
 export default function Swap() {
   const loadedUrlParams = useDefaultsFromURLSearch()
@@ -183,6 +184,8 @@ export default function Swap() {
 
   const { priceImpactWithoutFee } = computeTradePriceBreakdown(trade)
 
+  const [singleHopOnly] = useUserSingleHopOnly()
+
   const handleSwap = useCallback(() => {
     if (priceImpactWithoutFee && !confirmPriceImpactWithoutFee(priceImpactWithoutFee)) {
       return
@@ -209,6 +212,11 @@ export default function Swap() {
             getTradeVersion(trade)
           ].join('/')
         })
+
+        ReactGA.event({
+          category: 'Routing',
+          action: singleHopOnly ? 'Swap with multihop disabled' : 'Swap with multihop enabled'
+        })
       })
       .catch(error => {
         setSwapState({
@@ -219,7 +227,17 @@ export default function Swap() {
           txHash: undefined
         })
       })
-  }, [tradeToConfirm, account, priceImpactWithoutFee, recipient, recipientAddress, showConfirm, swapCallback, trade])
+  }, [
+    priceImpactWithoutFee,
+    swapCallback,
+    tradeToConfirm,
+    showConfirm,
+    recipient,
+    recipientAddress,
+    account,
+    trade,
+    singleHopOnly
+  ])
 
   // errors
   const [showInverted, setShowInverted] = useState<boolean>(false)
@@ -384,6 +402,7 @@ export default function Swap() {
             ) : noRoute && userHasSpecifiedInputOutput ? (
               <GreyCard style={{ textAlign: 'center' }}>
                 <TYPE.main mb="4px">Insufficient liquidity for this trade.</TYPE.main>
+                {singleHopOnly && <TYPE.main mb="4px">Try enabling multi-hop trades.</TYPE.main>}
               </GreyCard>
             ) : showApproveFlow ? (
               <RowBetween>

src/state/user/actions.ts

@@ -16,6 +16,7 @@ export interface SerializedPair {
 export const updateMatchesDarkMode = createAction<{ matchesDarkMode: boolean }>('user/updateMatchesDarkMode')
 export const updateUserDarkMode = createAction<{ userDarkMode: boolean }>('user/updateUserDarkMode')
 export const updateUserExpertMode = createAction<{ userExpertMode: boolean }>('user/updateUserExpertMode')
+export const updateUserSingleHopOnly = createAction<{ userSingleHopOnly: boolean }>('user/updateUserSingleHopOnly')
 export const updateUserSlippageTolerance = createAction<{ userSlippageTolerance: number }>(
   'user/updateUserSlippageTolerance'
 )

src/state/user/hooks.tsx

@@ -1,5 +1,6 @@
 import { ChainId, Pair, Token } from '@uniswap/sdk'
 import flatMap from 'lodash.flatmap'
+import ReactGA from 'react-ga'
 import { useCallback, useMemo } from 'react'
 import { shallowEqual, useDispatch, useSelector } from 'react-redux'
 import { BASES_TO_TRACK_LIQUIDITY_FOR, PINNED_PAIRS } from '../../constants'
@@ -17,7 +18,8 @@ import {
   updateUserDeadline,
   updateUserExpertMode,
   updateUserSlippageTolerance,
-  toggleURLWarning
+  toggleURLWarning,
+  updateUserSingleHopOnly
 } from './actions'
 
 function serializeToken(token: Token): SerializedToken {
@@ -81,6 +83,27 @@ export function useExpertModeManager(): [boolean, () => void] {
   return [expertMode, toggleSetExpertMode]
 }
 
+export function useUserSingleHopOnly(): [boolean, (newSingleHopOnly: boolean) => void] {
+  const dispatch = useDispatch<AppDispatch>()
+
+  const singleHopOnly = useSelector<AppState, AppState['user']['userSingleHopOnly']>(
+    state => state.user.userSingleHopOnly
+  )
+
+  const setSingleHopOnly = useCallback(
+    (newSingleHopOnly: boolean) => {
+      ReactGA.event({
+        category: 'Routing',
+        action: newSingleHopOnly ? 'enable single hop' : 'disable single hop'
+      })
+      dispatch(updateUserSingleHopOnly({ userSingleHopOnly: newSingleHopOnly }))
+    },
+    [dispatch]
+  )
+
+  return [singleHopOnly, setSingleHopOnly]
+}
+
 export function useUserSlippageTolerance(): [number, (slippage: number) => void] {
   const dispatch = useDispatch<AppDispatch>()
   const userSlippageTolerance = useSelector<AppState, AppState['user']['userSlippageTolerance']>(state => {

src/state/user/reducer.ts

@@ -13,7 +13,8 @@ import {
   updateUserExpertMode,
   updateUserSlippageTolerance,
   updateUserDeadline,
-  toggleURLWarning
+  toggleURLWarning,
+  updateUserSingleHopOnly
 } from './actions'
 
 const currentTimestamp = () => new Date().getTime()
@@ -27,6 +28,8 @@ export interface UserState {
 
   userExpertMode: boolean
 
+  userSingleHopOnly: boolean // only allow swaps on direct pairs
+
   // user defined slippage tolerance in bips, used in all txns
   userSlippageTolerance: number
 
@@ -58,6 +61,7 @@ export const initialState: UserState = {
   userDarkMode: null,
   matchesDarkMode: false,
   userExpertMode: false,
+  userSingleHopOnly: false,
   userSlippageTolerance: INITIAL_ALLOWED_SLIPPAGE,
   userDeadline: DEFAULT_DEADLINE_FROM_NOW,
   tokens: {},
@@ -103,6 +107,9 @@ export default createReducer(initialState, builder =>
       state.userDeadline = action.payload.userDeadline
       state.timestamp = currentTimestamp()
     })
+    .addCase(updateUserSingleHopOnly, (state, action) => {
+      state.userSingleHopOnly = action.payload.userSingleHopOnly
+    })
     .addCase(addSerializedToken, (state, { payload: { serializedToken } }) => {
       state.tokens[serializedToken.chainId] = state.tokens[serializedToken.chainId] || {}
       state.tokens[serializedToken.chainId][serializedToken.address] = serializedToken

src/utils/trades.ts

@@ -0,0 +1,29 @@
+import { Trade, currencyEquals, Percent } from '@uniswap/sdk'
+
+const ZERO_PERCENT = new Percent('0')
+const ONE_HUNDRED_PERCENT = new Percent('1')
+
+// returns whether tradeB is better than tradeA by at least a threshold percentage amount
+export function isTradeBetter(
+  tradeA: Trade | undefined | null,
+  tradeB: Trade | undefined | null,
+  minimumDelta: Percent = ZERO_PERCENT
+): boolean | undefined {
+  if (tradeA && !tradeB) return false
+  if (tradeB && !tradeA) return true
+  if (!tradeA || !tradeB) return undefined
+
+  if (
+    tradeA.tradeType !== tradeB.tradeType ||
+    !currencyEquals(tradeA.inputAmount.currency, tradeB.inputAmount.currency) ||
+    !currencyEquals(tradeB.outputAmount.currency, tradeB.outputAmount.currency)
+  ) {
+    throw new Error('Trades are not comparable')
+  }
+
+  if (minimumDelta.equalTo(ZERO_PERCENT)) {
+    return tradeA.executionPrice.lessThan(tradeB.executionPrice)
+  } else {
+    return tradeA.executionPrice.raw.multiply(minimumDelta.add(ONE_HUNDRED_PERCENT)).lessThan(tradeB.executionPrice)
+  }
+}