refactor: some clean up of the common bases code, add WETH

src/components/SearchModal/CommonBases.tsx

@@ -3,7 +3,7 @@ import { Text } from 'rebass'
 import { Currency } from '@uniswap/sdk-core'
 import styled from 'styled-components/macro'
 
-import { SUGGESTED_BASES } from '../../constants/routing'
+import { COMMON_BASES } from '../../constants/routing'
 import { currencyId } from '../../utils/currencyId'
 import { AutoColumn } from '../Column'
 import QuestionHelper from '../QuestionHelper'
@@ -35,7 +35,9 @@ export default function CommonBases({
   selectedCurrency?: Currency | null
   onSelect: (currency: Currency) => void
 }) {
-  return (
+  const bases = typeof chainId !== 'undefined' ? COMMON_BASES[chainId] ?? [] : []
+
+  return bases.length > 0 ? (
     <AutoColumn gap="md">
       <AutoRow>
         <Text fontWeight={500} fontSize={14}>
@@ -44,7 +46,7 @@ export default function CommonBases({
         <QuestionHelper text="These tokens are commonly paired with other tokens." />
       </AutoRow>
       <AutoRow gap="4px">
-        {(typeof chainId === 'number' ? SUGGESTED_BASES[chainId] ?? [] : []).map((currency: Currency) => {
+        {bases.map((currency: Currency) => {
           const isSelected = selectedCurrency?.equals(currency)
           return (
             <BaseWrapper
@@ -61,5 +63,5 @@ export default function CommonBases({
         })}
       </AutoRow>
     </AutoColumn>
-  )
+  ) : null
 }

src/constants/routing.ts

@@ -66,10 +66,18 @@ export const CUSTOM_BASES: { [chainId: number]: { [tokenAddress: string]: Token[
     [AMPL.address]: [DAI, WETH9[1]],
   },
 }
-// used for display in the default list when adding liquidity
-export const SUGGESTED_BASES: ChainCurrencyList = {
-  [1]: [Ether.onChain(1), DAI, USDC, USDT, WBTC],
+
+/**
+ * Shows up in the currency select for swap and add liquidity
+ */
+export const COMMON_BASES: ChainCurrencyList = {
+  [1]: [Ether.onChain(1), DAI, USDC, USDT, WBTC, WETH9[1]],
+  [3]: [Ether.onChain(3), WETH9[3]],
+  [4]: [Ether.onChain(4), WETH9[4]],
+  [5]: [Ether.onChain(5), WETH9[5]],
+  [42]: [Ether.onChain(42), WETH9[42]],
 }
+
 // used to construct the list of all pairs we consider by default in the frontend
 export const BASES_TO_TRACK_LIQUIDITY_FOR: ChainTokenList = {
   ...WETH_ONLY,