Adds calldata decoding task

packages/ethernaut-util/src/tasks/calldata.js

@@ -0,0 +1,41 @@
+const { ethers } = require('ethers')
+const types = require('ethernaut-common/src/validation/types')
+const output = require('ethernaut-common/src/ui/output')
+const EthernautCliError = require('ethernaut-common/src/error/error')
+
+require('../scopes/util')
+  .task('calldata', 'Decodes calldata of a tx')
+  .addPositionalParam(
+    'transactionId',
+    'The transaction to lookup',
+    undefined,
+    types.string,
+  )
+  .addPositionalParam(
+    'abi',
+    'The ABI of the contract to decode the calldata',
+    undefined,
+    types.array,
+  )
+  .setAction(async ({ transactionId, abi }, hre) => {
+    try {
+      const tx = await hre.ethers.provider.getTransaction(transactionId)
+
+      if (!tx) {
+        throw new EthernautCliError('ethernaut-network', 'No tx found.', false)
+      }
+
+      const calldata = tx.data
+      const iface = new ethers.utils.Interface(abi)
+      const decodedData = iface.parseTransaction({ data: calldata })
+
+      const callData = {
+        functionName: decodedData.name,
+        args: decodedData.args,
+      }
+
+      return output.resultBox(callData)
+    } catch (err) {
+      return output.errorBox(err)
+    }
+  })