From 1e6476ada73d1b76b3a3f6e0811a822eefd47f6c Mon Sep 17 00:00:00 2001
From: mzhu25 <mchl.zhu.96@gmail.com>
Date: Wed, 5 May 2021 22:29:24 -0700
Subject: [PATCH] Add ETH pseudo-address when wrapping/unwrapping in Multiplex
 multihop (#230)

* Add ETH pseudo-address when wrapping/unwrapping in Multiplex multihop

* Update changelog
---
 packages/asset-swapper/CHANGELOG.json                       | 4 ++++
 .../quote_consumers/exchange_proxy_swap_quote_consumer.ts   | 6 +++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/packages/asset-swapper/CHANGELOG.json b/packages/asset-swapper/CHANGELOG.json
index ec81115449..792c37e01e 100644
--- a/packages/asset-swapper/CHANGELOG.json
+++ b/packages/asset-swapper/CHANGELOG.json
@@ -5,6 +5,10 @@
             {
                 "note": "Tweak compiler settings for smaller sampler bytecode",
                 "pr": 229
+            },
+            {
+                "note": "Fix Multiplex multihop encoding for ETH buys/sells",
+                "pr": 230
             }
         ]
     },
diff --git a/packages/asset-swapper/src/quote_consumers/exchange_proxy_swap_quote_consumer.ts b/packages/asset-swapper/src/quote_consumers/exchange_proxy_swap_quote_consumer.ts
index 5645912f52..6efed0b41d 100644
--- a/packages/asset-swapper/src/quote_consumers/exchange_proxy_swap_quote_consumer.ts
+++ b/packages/asset-swapper/src/quote_consumers/exchange_proxy_swap_quote_consumer.ts
@@ -565,14 +565,17 @@ export class ExchangeProxySwapQuoteConsumer implements SwapQuoteConsumerBase {
 
     private _encodeMultiplexMultiHopFillCalldata(quote: SwapQuote, opts: ExchangeProxyContractOpts): string {
         const wrappedMultiHopCalls = [];
+        const tokens: string[] = [];
         if (opts.isFromETH) {
             wrappedMultiHopCalls.push({
                 selector: DUMMY_WETH_CONTRACT.getSelector('deposit'),
                 data: NULL_BYTES,
             });
+            tokens.push(ETH_TOKEN_ADDRESS);
         }
         const [firstHopOrder, secondHopOrder] = quote.orders;
         const intermediateToken = firstHopOrder.makerToken;
+        tokens.push(quote.takerToken, intermediateToken, quote.makerToken);
         for (const order of [firstHopOrder, secondHopOrder]) {
             switch (order.source) {
                 case ERC20BridgeSource.UniswapV2:
@@ -607,11 +610,12 @@ export class ExchangeProxySwapQuoteConsumer implements SwapQuoteConsumerBase {
                 selector: DUMMY_WETH_CONTRACT.getSelector('withdraw'),
                 data: NULL_BYTES,
             });
+            tokens.push(ETH_TOKEN_ADDRESS);
         }
         return this._exchangeProxy
             .multiHopFill(
                 {
-                    tokens: [quote.takerToken, intermediateToken, quote.makerToken],
+                    tokens,
                     sellAmount: quote.worstCaseQuoteInfo.totalTakerAmount,
                     calls: wrappedMultiHopCalls,
                 },