fix: smart router for ambient eth (#900)

Author: creed-victor

.changeset/healthy-spoons-allow.md

@@ -0,0 +1,5 @@
+---
+'@sovryn/sdk': patch
+---
+
+fix: ambient smart router

packages/sdk/src/_tests/swaps/smart-router.test.ts

@@ -91,7 +91,7 @@ describe('SmartRouter', () => {
     });
 
     it('get cheapest swap route for DLLR -> BTC', async () => {
-      const amount = ethers.utils.parseEther('20');
+      const amount = ethers.utils.parseEther('0.01');
       await expect(
         router.getBestQuote(chainId, dllr, btc, amount),
       ).resolves.toMatchObject({
@@ -101,7 +101,7 @@ describe('SmartRouter', () => {
     });
 
     it('get cheapest swap route for BTC -> DLLR', async () => {
-      const amount = ethers.utils.parseEther('20');
+      const amount = ethers.utils.parseEther('0.01');
       await expect(
         router.getBestQuote(chainId, dllr, btc, amount),
       ).resolves.toMatchObject({

packages/sdk/src/swaps/smart-router/routes/ambient.ts

@@ -356,13 +356,19 @@ export const ambientRoute: SwapRouteFunction = (
 
           const isLastPool = i === ambientPools.length - 1;
           if (isLastPool) {
-            const isBaseDestination =
-              destination.toLowerCase() ===
-              pool.baseToken.tokenAddr.toLowerCase();
-
-            // works for DLLR -> USDT -> USDC swap
-            baseHop.settlement.useSurplus = !isBaseDestination;
-            quoteHop.settlement.useSurplus = isBaseDestination;
+            // ether needs to be withdrawn from dex to user wallet with another hop
+            if (destination === constants.AddressZero) {
+              baseHop.settlement.useSurplus = true;
+              quoteHop.settlement.useSurplus = true;
+              const ethHop = order.appendHop(constants.AddressZero);
+              ethHop.settlement.useSurplus = false;
+            } else {
+              const isBaseDestination =
+                destination.toLowerCase() ===
+                pool.baseToken.tokenAddr.toLowerCase();
+              baseHop.settlement.useSurplus = !isBaseDestination;
+              quoteHop.settlement.useSurplus = isBaseDestination;
+            }
           }
         }