Clear url params on the network change (#397)

* Clear url params on the network change

* Fix for missing default token

src/custom/pages/Swap/SwapMod.tsx

@@ -107,6 +107,7 @@ import CowSubsidyModal from 'components/CowSubsidyModal'
 
 export default function Swap({
   history,
+  location,
   TradeBasicDetails,
   EthWethWrapMessage,
   SwitchToWethBtn,
@@ -124,6 +125,7 @@ export default function Swap({
   const { account, chainId } = useActiveWeb3React()
   const { isSupportedWallet } = useWalletInfo()
   const loadedUrlParams = useDefaultsFromURLSearch()
+  const previousChainId = usePrevious(chainId)
 
   // token warning stuff
   const [loadedInputCurrency, loadedOutputCurrency] = [
@@ -373,6 +375,13 @@ export default function Swap({
   // check if user has gone through approval process, used to show two step buttons, reset on token change
   const [approvalSubmitted, setApprovalSubmitted] = useState<boolean>(false)
 
+  // reset url query on network change
+  useEffect(() => {
+    if (chainId && previousChainId && chainId !== previousChainId) {
+      history.replace(location.pathname)
+    }
+  }, [chainId, history, location.pathname, previousChainId])
+
   // mark when a user has submitted an approval, reset onTokenSelection for input field
   useEffect(() => {
     if (approvalState === ApprovalState.PENDING) {

src/custom/state/swap/hooks.ts

@@ -465,7 +465,7 @@ export function useDefaultsFromURLSearch(): DefaultFromUrlSearch {
 
     setResult({ inputCurrencyId, outputCurrencyId })
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [chainId])
+  }, [chainId, parsedQs])
 
   return result
 }