feat: allow swapper to receive 2 tokens

src/contextualizers/heuristics/erc20Swap/erc20Swap.spec.ts

@@ -7,6 +7,7 @@ import erc20Swap0xd55dc9b2 from '../../test/transactions/erc20Swap-0xd55dc9b2.js
 import erc20Swap0x6ef80cce from '../../test/transactions/erc20Swap-0x6ef80cce.json';
 import erc20swap0x2c631258 from '../../test/transactions/erc20swap-0x2c631258.json';
 import erc20Swap0x96f5e3fb from '../../test/transactions/erc20Swap-0x96f5e3fb.json';
+import erc20Swap0x4d127476 from '../../test/transactions/erc20Swap-0x4d127476.json';
 import catchall0xc35c01ac from '../../test/transactions/catchall-0xc35c01ac.json';
 
 describe('ERC20 Swap', () => {
@@ -25,6 +26,9 @@ describe('ERC20 Swap', () => {
 
     const isERC20Swap4 = detect(erc20Swap0x96f5e3fb as unknown as Transaction);
     expect(isERC20Swap4).toBe(true);
+
+    const isERC20Swap5 = detect(erc20Swap0x4d127476 as unknown as Transaction);
+    expect(isERC20Swap5).toBe(true);
   });
 
   it('Should generate context', () => {
@@ -57,6 +61,12 @@ describe('ERC20 Swap', () => {
     expect(desc4).toBe(
       '0x605e05bf092ebd18e06d1b0f699df5b9dd85d452 SWAPPED 20398910132192029774490 0xeb1c32ea4e392346795aed3607f37646e2a9c13f for 2748.521373404267795478 ETH',
     );
+
+    const generated5 = generate(erc20Swap0x4d127476 as unknown as Transaction);
+    const desc5 = contextSummary(generated5.context);
+    expect(desc5).toBe(
+      '0x5507dbd48a5a5bace8a6030e878cc4e0af147c33 SWAPPED 0.029472790148424173 ETH for 600000000000000000000000 0xa6b280b42cb0b7c4a4f789ec6ccc3a7609a1bc39',
+    );
   });
 
   it('Should not detect as ERC20 Swap transaction', () => {

src/contextualizers/heuristics/erc20Swap/erc20Swap.ts

@@ -48,9 +48,8 @@ export function detect(transaction: Transaction): boolean {
   // From account (swapper) sent and received 1 asset
   if (
     !(
-      transaction.netAssetTransfers?.[transaction.from]?.received?.length ===
-        1 &&
-      transaction.netAssetTransfers?.[transaction.from]?.sent?.length === 1
+      transaction.netAssetTransfers?.[transaction.from]?.sent?.length === 1 &&
+      transaction.netAssetTransfers?.[transaction.from]?.received?.length >= 1
     )
   ) {
     return false;
@@ -59,12 +58,13 @@ export function detect(transaction: Transaction): boolean {
   const swapperSent = transaction.netAssetTransfers[transaction.from]
     .sent[0] as ERC20Asset;
   const swapperReceived = transaction.netAssetTransfers[transaction.from]
-    .received[0] as ERC20Asset;
+    .received as ERC20Asset[];
 
   // Swapper did not send and receive the same type of asset
   if (
-    swapperSent.type === swapperReceived.type &&
-    swapperSent.contract === swapperReceived.contract
+    swapperReceived.filter((asset) => asset.type === swapperSent.type).length &&
+    swapperReceived.filter((asset) => asset.contract === swapperSent.contract)
+      .length
   ) {
     return false;
   }
@@ -97,15 +97,20 @@ export function generate(transaction: Transaction): Transaction {
           ...assetSent[0],
           unit: 'wei',
         } as ContextETHType);
+
+  // Find the asset received with the most amount
+  const assetSwappedTo = assetReceived.reduce((max, item) => {
+    return item.value > max.value ? item : max;
+  }, assetReceived[0]);
   // Net asset transfers calls the token contract 'asset' instead of 'token'
   const swapTo =
-    assetReceived[0].type === AssetType.ERC20
+    assetSwappedTo.type === AssetType.ERC20
       ? ({
-          ...assetReceived[0],
-          token: assetReceived[0]?.contract,
+          ...assetSwappedTo,
+          token: assetSwappedTo?.contract,
         } as ContextERC20Type)
       : ({
-          ...assetReceived[0],
+          ...assetSwappedTo,
           unit: 'wei',
         } as ContextETHType);
   // Net asset transfers calls the token contract 'asset' instead of 'token'