feat: add last transfer heuristic for transactions which fail to parse

.env.example

@@ -3,3 +3,11 @@
 # Create an Alchemy API key: https://docs.alchemy.com/docs/alchemy-quickstart-guide
 # Or even better, run a local node: https://ethereum.org/en/run-a-node and use it's RPC URL.
 ETH_MAINNET_RPC="https://eth-mainnet.g.alchemy.com/v2/<your-api-key>"
+ALCHEMY_API_KEY="your-alchemy-api-key-here"
+
+
+# Required: Quicknode API keys for specific chain tests
+# Sign up at https://quicknode.com for free trial with debug method support
+QUICKNODE_BNB_CHAIN_API_KEY="your-quicknode-bnb-key"
+QUICKNODE_MANTLE_API_KEY="your-quicknode-mantle-key" 
+QUICKNODE_MODE_API_KEY="your-quicknode-mode-key"

README.md

@@ -60,7 +60,7 @@
         <br>Mantle
       </div>
     </td>
-        <td style="width:100px; text-align:center;">
+    <td style="width:100px; text-align:center;">
       <div align="center">
         <img alt="mantle" src="https://raw.githubusercontent.com/rainbow-me/assets/master/blockchains/monad/info/logo.png" width="22"/>
         <br>Monad
@@ -84,14 +84,14 @@
         <br>Scroll
       </div>
     </td>
+  </tr>
+  <tr>
     <td style="width:100px; text-align:center;">
       <div align="center">
         <img alt="coming soon" src="https://raw.githubusercontent.com/rainbow-me/assets/master/blockchains/mode/info/logo.png" width="22"/>
         <br>Mode
       </div>
     </td>
-  </tr>
-  <tr>
     <td style="width:100px; text-align:center;">
       <div align="center">
         <img alt="Worldchain" src="https://cdn.prod.website-files.com/6503306c491d20f69e484470/6718ce22ee5879d832765fd6_66ced64f18a10922ffcff77d_65d8bce782514cfb6c149b7a_1VQdZPHJ_400x400.webp" width="22"/>
@@ -121,15 +121,15 @@
         <img alt="coming soon" src="https://i.imgur.com/CexTjqF.png" width="22"/>
         <br>🔜
       </div>
-    </td>
+    </td>   
+  </tr>
+  <tr>
     <td style="width:100px; text-align:center;">
       <div align="center">
         <img alt="coming soon" src="https://cdn.prod.website-files.com/63692bf32544bee8b1836ea6/637b01428c7bd8e16af26756_favicon-32.png" width="22"/>
         <br>🔜
       </div>
-    </td>    
-  </tr>
-  <tr>
+    </td> 
     <td style="width:100px; text-align:center;">
       <div align="center">
         <img alt="coming soon" src="https://i.imgur.com/OPA8A9u.png" width="22"/>

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(
@@ -224,14 +238,22 @@ export async function parseSwap({
     };
   }
 
-  /* v8 ignore start */
-  if (!output) {
-    console.error(
-      "File a bug report here, including the expected results (URL to a block explorer) and the unexpected results: https://github.com/0xProject/0x-parser/issues/new/choose."
-    );
-    return null;
-  }
-  /* v8 ignore stop */
+if (!output) {
+  if (!logs.length) /* v8 ignore next */ return null;    
+    const lastTransfer = logs[logs.length - 1];
+    return {
+      tokenIn: {
+        symbol: input.symbol,
+        amount: input.amount,
+        address: input.address,
+      },
+      tokenOut: {
+        symbol: lastTransfer.symbol,
+        address: lastTransfer.address,
+        amount: lastTransfer.amount
+      }
+    };
+}
 
   return {
     tokenIn: {
@@ -245,4 +267,4 @@ export async function parseSwap({
       address: output.address,
     },
   };
-}
+}

src/tests/index.test.ts

@@ -1455,3 +1455,81 @@ test("logs a warning for reverted transactions)", async () => {
 
   warnSpy.mockRestore();
 });
+
+//https://etherscan.io/tx/0x7eea91c5c715ef4bb1e39ddf4c7832113693e87c18392740353d5ae669406a46
+test("parse a swap on Ethereum (USDC for WMON) with SettlerIntent", async () => {
+  const transactionHash = "0x7eea91c5c715ef4bb1e39ddf4c7832113693e87c18392740353d5ae669406a46";
+
+  const result = await parseSwap({
+    publicClient: publicClient, 
+    transactionHash,
+  });
+
+  expect(result).toEqual({
+    tokenIn: {
+      symbol: "USDC",
+      amount: "1000.080833", 
+      address: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
+    },
+    tokenOut: {
+      symbol: "WMON", 
+      amount: "22204.573291811240325155", 
+      address: "0x6917037F8944201b2648198a89906Edf863B9517",
+    },
+  });
+});
+
+// https://optimistic.etherscan.io/tx/0xdee6f4fea0250f297ed9663c4ca4479e8a253c62e16faa60759e25832cd1f34f
+test("parse a swap on Optimism (wstETH for ETH) via Balancer pool", async () => {
+  const publicClient = createPublicClient({
+    chain: optimism,
+    transport: http(
+      `https://opt-mainnet.g.alchemy.com/v2/${process.env.ALCHEMY_API_KEY}`
+    ),
+  }) as PublicClient<Transport, Chain>;
+
+  const transactionHash =
+    "0xdee6f4fea0250f297ed9663c4ca4479e8a253c62e16faa60759e25832cd1f34f";
+
+  const result = await parseSwap({
+    publicClient,
+    transactionHash,
+  });
+
+  expect(result).toEqual({
+    tokenIn: {
+      symbol: "wstETH",
+      amount: "0.008868",
+      address: "0x1F32b1c2345538c0c6f582fCB022739c4A194Ebb",
+    },
+    tokenOut: {
+      symbol: "ETH",
+      amount: "0.010671015314389981",
+      address: NATIVE_TOKEN_ADDRESS,
+    },
+  });
+});
+
+// https://etherscan.io/tx/0x967cb342227a2541a845058862e70833d638bf5bb7ce229c6506466dbb43a004
+test("parse a swap on Mainnet (TRG for SHITCOIN)", async () => {
+  const transactionHash =
+    "0x967cb342227a2541a845058862e70833d638bf5bb7ce229c6506466dbb43a004" as `0x${string}`;
+
+  const result = await parseSwap({
+    publicClient,
+    transactionHash,
+  });
+
+  expect(result).toEqual({
+    tokenIn: {
+      symbol: "TRG",
+      amount: "5053634.405791388940070628",
+      address: "0x93eEB426782BD88fCD4B48D7b0368CF061044928",
+    },
+    tokenOut: {
+      symbol: "SHITCOIN",
+      amount: "881342.949331124",
+      address: "0x4fD1b29d1aAFeA37A2d19E7d912b6eda44dBd82C",
+    },
+  });
+});