Slippage warning (#292)

* add rudimentary slippage warning

fix address checksum bug

debounce address input

alway show tx details if valid trade

* fix estimated copy

public/locales/en.json

@@ -26,6 +26,7 @@
   "unlockTokenCont": "Please unlock token to continue.",
   "transactionDetails": "Transaction Details",
   "hideDetails": "Hide Details",
+  "slippageWarning": "Slippage Warning",
   "youAreSelling": "You are selling",
   "orTransFail": "or the transaction will fail.",
   "youWillReceive": "You will receive at least",

src/components/AddressInputPanel/index.js

@@ -4,20 +4,23 @@ import { useTranslation } from 'react-i18next'
 import { useWeb3Context } from 'web3-react'
 
 import { isAddress } from '../../utils'
+import { useDebounce } from '../../hooks'
 // import QrCode from '../QrCode' // commented out pending further review
 
 import './address-input-panel.scss'
 
-export default function AddressInputPanel({ title, onChange = () => {}, onError = () => {} }) {
+export default function AddressInputPanel({ title, initialInput = '', onChange = () => {}, onError = () => {} }) {
   const { t } = useTranslation()
 
   const { library } = useWeb3Context()
 
-  const [input, setInput] = useState('')
+  const [input, setInput] = useState(initialInput)
+  const debouncedInput = useDebounce(input, 150)
+
   const [data, setData] = useState({ address: undefined, name: undefined })
   const [error, setError] = useState(false)
 
-  // keep stuff in sync
+  // keep data and errors in sync
   useEffect(() => {
     onChange({ address: data.address, name: data.name })
   }, [onChange, data.address, data.name])
@@ -25,29 +28,30 @@ export default function AddressInputPanel({ title, onChange = () => {}, onError
     onError(error)
   }, [onError, error])
 
+  // run parser on debounced input
   useEffect(() => {
     let stale = false
 
-    if (isAddress(input)) {
-      library.lookupAddress(input).then(name => {
+    if (isAddress(debouncedInput)) {
+      library.lookupAddress(debouncedInput).then(name => {
         if (!stale) {
           // if an ENS name exists, set it as the destination
           if (name) {
             setInput(name)
           } else {
-            setData({ address: input, name: '' })
+            setData({ address: debouncedInput, name: '' })
             setError(null)
           }
         }
       })
     } else {
-      if (input !== '') {
+      if (debouncedInput !== '') {
         try {
-          library.resolveName(input).then(address => {
+          library.resolveName(debouncedInput).then(address => {
             if (!stale) {
-              // if the input name resolves to an address
+              // if the debounced input name resolves to an address
               if (address) {
-                setData({ address: address, name: input })
+                setData({ address: address, name: debouncedInput })
                 setError(null)
               } else {
                 setError(true)
@@ -62,10 +66,20 @@ export default function AddressInputPanel({ title, onChange = () => {}, onError
 
     return () => {
       stale = true
+    }
+  }, [debouncedInput, library, onChange, onError])
+
+  function onInput(event) {
+    if (data.address !== undefined || data.name !== undefined) {
       setData({ address: undefined, name: undefined })
+    }
+    if (error !== undefined) {
       setError()
     }
-  }, [input, library, onChange, onError])
+    const input = event.target.value
+    const checksummedInput = isAddress(input)
+    setInput(checksummedInput || input)
+  }
 
   return (
     <div className="currency-input-panel">
@@ -83,11 +97,15 @@ export default function AddressInputPanel({ title, onChange = () => {}, onError
           <div className="currency-input-panel__input-row">
             <input
               type="text"
+              autoComplete="off"
+              autoCorrect="off"
+              autoCapitalize="off"
+              spellCheck="false"
               className={classnames('address-input-panel__input', {
                 'address-input-panel__input--error': input !== '' && error
               })}
               placeholder="0x1234..."
-              onChange={e => setInput(e.target.value)}
+              onChange={onInput}
               value={input}
             />
           </div>

src/components/ContextualInfoNew/contextual-info.scss

+@import '../../variables.scss';
+
+.contextual-info {
+  &__summary-wrapper {
+    color: $dove-gray;
+    font-size: 0.75rem;
+    text-align: center;
+    margin-top: 1rem;
+    padding-top: 1rem;
+  }
+
+  &--error {
+    color: $salmon-red;
+  }
+
+  &__details {
+    background-color: $concrete-gray;
+    padding: 1.5rem;
+    border-radius: 1rem;
+    font-size: 0.75rem;
+    margin-top: 1rem;
+  }
+
+  &__open-details-container {
+    cursor: pointer;
+
+    @extend %row-nowrap;
+    align-items: center;
+    justify-content: center;
+    font-size: 0.75rem;
+    color: $royal-blue;
+
+    span {
+      margin-right: 12px;
+    }
+
+    img {
+      height: 0.75rem;
+      width: 0.75rem;
+    }
+  }
+}

src/components/ContextualInfoNew/index.js

+import React, { useState } from 'react'
+import styled from 'styled-components'
+import c from 'classnames'
+
+import { ReactComponent as Dropup } from '../../assets/images/dropup-blue.svg'
+import { ReactComponent as Dropdown } from '../../assets/images/dropdown-blue.svg'
+
+import './contextual-info.scss'
+
+const WrappedDropup = ({ isError, ...rest }) => <Dropup {...rest} />
+const ColoredDropup = styled(WrappedDropup)`
+  path {
+    stroke: ${props => props.isError && props.theme.salmonRed};
+  }
+`
+
+const WrappedDropdown = ({ isError, ...rest }) => <Dropdown {...rest} />
+const ColoredDropdown = styled(WrappedDropdown)`
+  path {
+    stroke: ${props => props.isError && props.theme.salmonRed};
+  }
+`
+
+export default function ContextualInfo({
+  openDetailsText = 'Transaction Details',
+  closeDetailsText = 'Hide Details',
+  contextualInfo = '',
+  allowExpand = false,
+  renderTransactionDetails = () => {},
+  isError = false
+}) {
+  const [showDetails, setShowDetails] = useState(false)
+
+  return !allowExpand ? (
+    <div className={c({ 'contextual-info--error': isError }, 'contextual-info__summary-wrapper')}>
+      <div>{contextualInfo}</div>
+    </div>
+  ) : (
+    <>
+      <div
+        key="open-details"
+        className="contextual-info__summary-wrapper contextual-info__open-details-container"
+        onClick={() => setShowDetails(s => !s)}
+      >
+        <>
+          <span className={c({ 'contextual-info--error': isError })}>
+            {contextualInfo ? contextualInfo : showDetails ? closeDetailsText : openDetailsText}
+          </span>
+          {showDetails ? <ColoredDropup isError={isError} /> : <ColoredDropdown isError={isError} />}
+        </>
+      </div>
+      {showDetails && <div className="contextual-info__details">{renderTransactionDetails()}</div>}
+    </>
+  )
+}

src/components/CurrencyInputPanel/index.js

@@ -281,6 +281,12 @@ function CurrencySelectModal({ onClose, onTokenSelect }) {
     }
   }, [])
 
+  function onInput(event) {
+    const input = event.target.value
+    const checksummedInput = isAddress(input)
+    setSearchQuery(checksummedInput || input)
+  }
+
   return (
     <Modal onClose={_onClose}>
       <CSSTransitionGroup
@@ -298,9 +304,7 @@ function CurrencySelectModal({ onClose, onTokenSelect }) {
               type="text"
               placeholder={t('searchOrPaste')}
               className="token-modal__search-input"
-              onChange={e => {
-                setSearchQuery(e.target.value)
-              }}
+              onChange={onInput}
             />
             <img src={SearchIcon} className="token-modal__search-icon" alt="search" />
           </div>

src/hooks/index.js

-import { useMemo, useCallback, useEffect } from 'react'
+import { useState, useMemo, useCallback, useEffect } from 'react'
 import { useWeb3Context } from 'web3-react'
 
 import ERC20_ABI from '../abi/erc20'
 import { getContract, getFactoryContract, getExchangeContract } from '../utils'
 
+// modified from https://usehooks.com/useDebounce/
+export function useDebounce(value, delay) {
+  const [debouncedValue, setDebouncedValue] = useState(value)
+
+  useEffect(() => {
+    // Update debounced value after delay
+    const handler = setTimeout(() => {
+      setDebouncedValue(value)
+    }, delay)
+
+    // Cancel the timeout if value changes (also on delay change or unmount)
+    // This is how we prevent debounced value from updating if value is changed ...
+    // .. within the delay period. Timeout gets cleared and restarted.
+    return () => {
+      clearTimeout(handler)
+    }
+  }, [value, delay])
+
+  return debouncedValue
+}
+
 // modified from https://usehooks.com/useKeyPress/
 export function useBodyKeyDown(targetKey, onKeyDown, suppressOnKeyDown = false) {
   const downHandler = useCallback(

src/pages/Pool/AddLiquidity.js

@@ -297,7 +297,7 @@ export default function AddLiquidity() {
 
     const deadline = Math.ceil(Date.now() / 1000) + DEADLINE_FROM_NOW
     const estimatedGasLimit = await exchangeContract.estimate.addLiquidity(
-      isNewExchange ? inputValueParsed : liquidityTokensMin,
+      isNewExchange ? ethers.constants.Zero : liquidityTokensMin,
       isNewExchange ? outputValueParsed : outputValueMax,
       deadline,
       {
@@ -307,7 +307,7 @@ export default function AddLiquidity() {
 
     exchangeContract
       .addLiquidity(
-        isNewExchange ? inputValueParsed : liquidityTokensMin,
+        isNewExchange ? ethers.constants.Zero : liquidityTokensMin,
         isNewExchange ? outputValueParsed : outputValueMax,
         deadline,
         {
@@ -476,7 +476,7 @@ export default function AddLiquidity() {
       </OversizedPanel>
       <CurrencyInputPanel
         title={t('deposit')}
-        description={isNewExchange ? `(${t('estimated')})` : ''}
+        description={isNewExchange ? '' : outputValue ? `(${t('estimated')})` : ''}
         extraText={outputBalance && formatBalance(amountFormatter(outputBalance, decimals, Math.min(decimals, 4)))}
         selectedTokenAddress={outputCurrency}
         onCurrencySelected={outputCurrency => {

src/pages/Pool/CreateExchange.js

@@ -18,7 +18,7 @@ function CreateExchange({ history, location }) {
   const factory = useFactoryContract()
 
   const [tokenAddress, setTokenAddress] = useState({
-    address: (location.state && location.state.tokenAddress) || '',
+    address: '',
     name: ''
   })
   const [tokenAddressError, setTokenAddressError] = useState()
@@ -74,7 +74,12 @@ function CreateExchange({ history, location }) {
 
   return (
     <>
-      <AddressInputPanel title={t('tokenAddress')} onChange={setTokenAddress} onError={setTokenAddressError} />
+      <AddressInputPanel
+        title={t('tokenAddress')}
+        initialInput={(location.state && location.state.tokenAddress) || ''}
+        onChange={setTokenAddress}
+        onError={setTokenAddressError}
+      />
       <OversizedPanel hideBottom>
         <div className="pool__summary-panel">
           <div className="pool__exchange-rate-wrapper">

src/pages/Pool/RemoveLiquidity.js

@@ -284,7 +284,7 @@ export default function RemoveLiquidity() {
       </OversizedPanel>
       <CurrencyInputPanel
         title={t('output')}
-        description={`(${t('estimated')})`}
+        description={ethWithdrawn && tokenWithdrawn ? `(${t('estimated')})` : ''}
         key="remove-liquidity-input"
         renderInput={() =>
           ethWithdrawn && tokenWithdrawn ? (

src/pages/Swap/index.js

@@ -5,7 +5,7 @@ import { useWeb3Context } from 'web3-react'
 import { ethers } from 'ethers'
 
 import CurrencyInputPanel from '../../components/CurrencyInputPanel'
-import ContextualInfo from '../../components/ContextualInfo'
+import NewContextualInfo from '../../components/ContextualInfoNew'
 import OversizedPanel from '../../components/OversizedPanel'
 import ArrowDownBlue from '../../assets/images/arrow-down-blue.svg'
 import ArrowDownGrey from '../../assets/images/arrow-down-grey.svg'
@@ -425,18 +425,16 @@ export default function Swap() {
   )
 
   const percentSlippage =
-    exchangeRate &&
-    marketRate &&
-    amountFormatter(
-      exchangeRate
+    exchangeRate && marketRate
+      ? exchangeRate
           .sub(marketRate)
           .abs()
           .mul(ethers.utils.bigNumberify(10).pow(ethers.utils.bigNumberify(18)))
           .div(marketRate)
-        .sub(ethers.utils.bigNumberify(3).mul(ethers.utils.bigNumberify(10).pow(ethers.utils.bigNumberify(15)))),
-      16,
-      2
-    )
+          .sub(ethers.utils.bigNumberify(3).mul(ethers.utils.bigNumberify(10).pow(ethers.utils.bigNumberify(15))))
+      : undefined
+  const percentSlippageFormatted = percentSlippage && amountFormatter(percentSlippage, 16, 2)
+  const slippageWarning = percentSlippage && percentSlippage.gte(ethers.utils.parseEther('.1')) // 10%
 
   const isValid = exchangeRate && inputError === null && independentError === null
 
@@ -479,7 +477,7 @@ export default function Swap() {
             {t('orTransFail')}
           </div>
           <div className="send__last-summary-text">
-            {t('priceChange')} {b(`${percentSlippage}%`)}.
+            {t('priceChange')} {b(`${percentSlippageFormatted}%`)}.
           </div>
         </div>
       )
@@ -509,7 +507,7 @@ export default function Swap() {
             {t('orTransFail')}
           </div>
           <div className="send__last-summary-text">
-            {t('priceChange')} {b(`${percentSlippage}%`)}.
+            {t('priceChange')} {b(`${percentSlippageFormatted}%`)}.
           </div>
         </div>
       )
@@ -533,10 +531,11 @@ export default function Swap() {
     }
 
     return (
-      <ContextualInfo
+      <NewContextualInfo
         openDetailsText={t('transactionDetails')}
         closeDetailsText={t('hideDetails')}
-        contextualInfo={contextualInfo}
+        contextualInfo={contextualInfo ? contextualInfo : slippageWarning ? t('slippageWarning') : ''}
+        allowExpand={!!(inputCurrency && outputCurrency && inputValueParsed && outputValueParsed)}
         isError={isError}
         renderTransactionDetails={renderTransactionDetails}
       />

src/theme/index.js

@@ -4,6 +4,7 @@ import { ThemeProvider as StyledComponentsThemeProvider, createGlobalStyle } fro
 const theme = {
   uniswapPink: '#DC6BE5',
   royalBlue: '#2f80ed',
+  salmonRed: '#ff6871',
   white: '#FFF',
   black: '#000'
 }

src/utils/index.js

@@ -15,16 +15,17 @@ export const ERROR_CODES = ['TOKEN_NAME', 'TOKEN_SYMBOL', 'TOKEN_DECIMALS'].redu
 )
 
 export function safeAccess(object, path) {
-  return path.reduce(
+  return object
+    ? path.reduce(
         (accumulator, currentValue) => (accumulator && accumulator[currentValue] ? accumulator[currentValue] : null),
         object
       )
+    : null
 }
 
 export function isAddress(value) {
   try {
-    ethers.utils.getAddress(value)
-    return true
+    return ethers.utils.getAddress(value.toLowerCase())
   } catch {
     return false
   }