add debug comments for SettlerIntent txns

Author: barskhianfannie

src/index.ts

@@ -37,28 +37,40 @@ export async function parseSwap({
   if (!isChainIdSupported(chainId)) {
     throw new Error(`chainId ${chainId} is unsupported…`);
   }
-
+// This code extends the viem publicClient with a custom method called traceCall.
   const client = publicClient.extend((client) => ({
     async traceCall(args: { hash: Hash }) {
       return client.request<TraceTransactionSchema>({
-        method: "debug_traceTransaction",
+        method: "debug_traceTransaction", //replays the txn & returns execution data
+        /**
+         * The callTracer returns a tree of all internal calls made during execution, including:
+            Contract-to-contract calls
+            Internal ETH transfers
+            Call depth, gas used, return values
+         */
         params: [args.hash, { tracer: "callTracer" }],
+        //
       });
     },
   }));
 
+  // trace - ETH transfers, contract calls
+  // transaction- from, to, value, input calldata
+  // transactionReceipt - status, gas used, logs emitted
   const [trace, transaction, transactionReceipt] = await Promise.all([
     client.traceCall({ hash }),
     publicClient.getTransaction({ hash }),
     publicClient.getTransactionReceipt({ hash }),
   ]);
 
   const { from: taker, value, to } = transaction;
-
-  const isToERC4337 = to === ERC_4337_ENTRY_POINT.toLowerCase();
-
+  // The Issue: FOR SETTLERINTENT TXNS only - The taker address passed into calculateNativeTransfer is not the actual takers address, causing nativeAmountToTaker to be 0 when it shouldn't be
+  // Potential Solution: we need to determine if the txn is a settlerIntent txn, if so we 
+  // can determine the taker from the to address in the last trace call.
+  const actualTaker =  trace.calls[trace.calls.length-1].to;
+  //Scans the execution trace for any internal ETH transfers to the taker's address
   const nativeAmountToTaker = calculateNativeTransfer(trace, {
-    recipient: taker,
+    recipient: taker, // for Settler Intent txns we should use actualTaker
   });
 
   if (transactionReceipt.status === "reverted") {
@@ -74,7 +86,9 @@ export async function parseSwap({
     publicClient,
     transactionReceipt,
   });
-
+  // if a Smart wallet, then the way in which we determine the taker is different than traditional EOA's. 
+  // The actual taker is the smart contract embedded in the wallet
+  const isToERC4337 = to === ERC_4337_ENTRY_POINT.toLowerCase();
   if (isToERC4337) {
     if (!smartContractWallet) {
       throw new Error(

src/tests/index.test.ts

@@ -1503,15 +1503,15 @@ test("parse a swap on Optimism (wstETH for ETH) via Balancer pool", async () =>
       address: "0x1F32b1c2345538c0c6f582fCB022739c4A194Ebb",
     },
     tokenOut: {
-      symbol: "WETH",
-      amount: "0.010698199301849867",
-      address: "0x4200000000000000000000000000000000000006",
+      symbol: "ETH",
+      amount: "0.010671015314389981",
+      address: NATIVE_TOKEN_ADDRESS,
     },
   });
 });
 
 // https://etherscan.io/tx/0x967cb342227a2541a845058862e70833d638bf5bb7ce229c6506466dbb43a004
-test.only("parse a swap on Mainnet (TRG for SHITCOIN)", async () => {
+test("parse a swap on Mainnet (TRG for SHITCOIN)", async () => {
   const transactionHash =
     "0x967cb342227a2541a845058862e70833d638bf5bb7ce229c6506466dbb43a004" as `0x${string}`;