fix: use native eth for caching routing lambda token in and token out

lib/handlers/router-entities/route-caching/dynamo-route-caching-provider.ts

@@ -18,6 +18,7 @@ import { PairTradeTypeChainId } from './model/pair-trade-type-chain-id'
 import { CachedRoutesMarshaller } from '../../marshalling/cached-routes-marshaller'
 import { PromiseResult } from 'aws-sdk/lib/request'
 import { DEFAULT_BLOCKS_TO_LIVE_ROUTES_DB } from '../../../util/defaultBlocksToLiveRoutesDB'
+import { getSymbolOrAddress } from '../../../util/getSymbolOrAddress'
 
 interface ConstructorParams {
   /**
@@ -354,9 +355,9 @@ export class DynamoRouteCachingProvider extends IRouteCachingProvider {
   ): void {
     const payload = {
       queryStringParameters: {
-        tokenInAddress: partitionKey.currencyIn,
+        tokenInAddress: getSymbolOrAddress(partitionKey.currencyIn, partitionKey.chainId),
         tokenInChainId: partitionKey.chainId.toString(),
-        tokenOutAddress: partitionKey.currencyOut,
+        tokenOutAddress: getSymbolOrAddress(partitionKey.currencyOut, partitionKey.chainId),
         tokenOutChainId: partitionKey.chainId.toString(),
         amount: amount.quotient.toString(),
         type: partitionKey.tradeType === 0 ? 'exactIn' : 'exactOut',

lib/util/getSymbolOrAddress.ts

@@ -0,0 +1,10 @@
+import { ChainId } from '@uniswap/sdk-core'
+import { ADDRESS_ZERO } from '@uniswap/router-sdk'
+import { nativeOnChain } from '@uniswap/smart-order-router/build/main/util/chains'
+export function getSymbolOrAddress(address: string, chainId: ChainId): string {
+  if (address === ADDRESS_ZERO) {
+    return nativeOnChain(chainId)?.symbol ?? 'ETH'
+  } else {
+    return address
+  }
+}

test/mocha/unit/util/getSymbolOrAddress.ts

@@ -0,0 +1,14 @@
+import { getSymbolOrAddress } from '../../../../lib/util/getSymbolOrAddress'
+import { ADDRESS_ZERO } from '@uniswap/router-sdk'
+import { ChainId } from '@uniswap/sdk-core'
+import { expect } from 'chai'
+
+describe('get symbol or address', () => {
+  it('should get symbol or address on L1', async () => {
+    expect(getSymbolOrAddress(ADDRESS_ZERO, ChainId.MAINNET)).to.eq('ETH')
+  })
+
+  it('should get symbol or address on Polygon', async () => {
+    expect(getSymbolOrAddress(ADDRESS_ZERO, ChainId.POLYGON)).to.eq('MATIC')
+  })
+})