detect tx reverts

src/worker.js

@@ -36,6 +36,8 @@ let tree
 let txManager
 let controller
 let swap
+let minerContract
+let proxyContract
 const redis = new Redis(redisUrl)
 const redisSubscribe = new Redis(redisUrl)
 const gasPriceOracle = new GasPriceOracle({ defaultRpc: httpRpcUrl })
@@ -83,6 +85,8 @@ async function start() {
   const { CONFIRMATIONS, MAX_GAS_PRICE } = process.env
   txManager = new TxManager({ privateKey, rpcUrl: httpRpcUrl, config: { CONFIRMATIONS, MAX_GAS_PRICE } })
   swap = new web3.eth.Contract(swapABI, await resolver.resolve(torn.rewardSwap.address))
+  minerContract = new web3.eth.Contract(miningABI, await resolver.resolve(torn.miningV2.address))
+  proxyContract = new web3.eth.Contract(tornadoProxyABI, await resolver.resolve(torn.tornadoProxy.address))
   redisSubscribe.subscribe('treeUpdate', fetchTree)
   await fetchTree()
   const provingKeys = {
@@ -175,8 +179,7 @@ async function getTxObject({ data }) {
   if (data.type === jobType.TORNADO_WITHDRAW) {
     let contract, calldata
     if (getInstance(data.contract).currency === 'eth') {
-      const tornadoProxyAddress = await resolver.resolve(torn.tornadoProxy.address)
-      contract = new web3.eth.Contract(tornadoProxyABI, tornadoProxyAddress)
+      contract = proxyContract
       calldata = contract.methods.withdraw(data.contract, data.proof, ...data.args).encodeABI()
     } else {
       contract = new web3.eth.Contract(tornadoABI, data.contract)
@@ -188,17 +191,65 @@ async function getTxObject({ data }) {
       data: calldata,
     }
   } else {
-    const minerAddress = await resolver.resolve(torn.miningV2.address)
-    const contract = new web3.eth.Contract(miningABI, minerAddress)
     const method = data.type === jobType.MINING_REWARD ? 'reward' : 'withdraw'
-    const calldata = contract.methods[method](data.proof, data.args).encodeABI()
+    const calldata = minerContract.methods[method](data.proof, data.args).encodeABI()
     return {
-      to: minerAddress,
+      to: minerContract._address,
       data: calldata,
     }
   }
 }
 
+function extractRevertReason(msg) {
+  console.log('RAW error message:', msg)
+
+  if (!msg.startsWith('Node error: ')) {
+    console.log('Failed to parse error message from Ethereum call: ' + msg)
+    return null
+  }
+
+  // Trim "Node error: "
+  const errorObjectStr = msg.slice(12)
+  // Parse the error object
+  const errorObject = JSON.parse(errorObjectStr)
+
+  if (!errorObject.data) {
+    console.log('Failed to parse data field error object:' + errorObjectStr)
+    return null
+  }
+
+  if (errorObject.data.startsWith('Reverted 0x')) {
+    // Trim "Reverted 0x" from the data field
+    msg = errorObject.data.slice(11)
+  } else if (errorObject.data.startsWith('0x')) {
+    // Trim "0x" from the data field
+    msg = errorObject.data.slice(2)
+  } else {
+    console.log('Failed to parse data field error object:' + errorObjectStr)
+    return null
+  }
+
+  // Get the length of the revert reason
+  const strLen = parseInt(msg.slice(8 + 64, 8 + 128), 16)
+  // Using the length and known offset, extract and convert the revert reason
+  const reasonCodeHex = msg.slice(8 + 128, 8 + 128 + (strLen * 2))
+  // Convert reason from hex to string
+  const reason = web3.utils.hexToAscii('0x' + reasonCodeHex)
+  return reason
+}
+
+async function isOutdatedTreeRevert(receipt, currentTx) {
+  try {
+    await web3.eth.call(currentTx.tx, receipt.blockNumber)
+    console.log('Simulated call successful')
+    return false
+  } catch(e) {
+    const reason = extractRevertReason(e.message)
+    console.log('Decoded revert reason:', reason)
+    return reason === 'Outdated account merkle root' || reason === 'Outdated tree update merkle root'
+  }
+}
+
 async function processJob(job) {
   try {
     if (!jobType[job.data.type]) {
@@ -207,6 +258,15 @@ async function processJob(job) {
     currentJob = job
     await updateStatus(status.ACCEPTED)
     console.log(`Start processing a new ${job.data.type} job #${job.id}`)
+    await submitTx(job)
+  } catch (e) {
+    console.error(e)
+    await updateStatus(status.FAILED)
+    throw e
+  }
+}
+
+async function submitTx(job, retry = 0) {
   await checkFee(job)
   currentTx = await txManager.createTx(await getTxObject(job))
 
@@ -215,7 +275,7 @@ async function processJob(job) {
   }
 
   try {
-      await currentTx
+    const receipt = await currentTx
       .send()
       .on('transactionHash', txHash => {
         updateTxHash(txHash)
@@ -227,15 +287,24 @@ async function processJob(job) {
       })
       .on('confirmations', updateConfirmations)
 
+    if (receipt.status === 1) {
       await updateStatus(status.CONFIRMED)
-    } catch (e) {
-      console.error('Revert', e)
-      throw new Error(`Revert by smart contract ${e.message}`)
+    } else {
+      if (job.data.type !== jobType.TORNADO_WITHDRAW && await isOutdatedTreeRevert(receipt, currentTx)) {
+        if (retry < 3) {
+          await submitTx(job, retry + 1)
+        } else {
+          throw new Error('Tree update retry limit exceeded')
+        }
+      } else {
+        throw new Error('Submitted transaction failed')
+      }
     }
   } catch (e) {
-    console.error(e)
-    await updateStatus(status.FAILED)
-    throw e
+    // todo this could result in duplicated error logs
+    // todo handle a case where account tree is still not up to date (wait and retry)?
+    console.error('Revert', e)
+    throw new Error(`Revert by smart contract ${e.message}`)
   }
 }