No hashing, paymaster script

contracts/ZeekSecretMessages.sol → contracts/ZeekMessages.sol

@@ -1,8 +1,8 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
-contract ZeekSecretMessages {
-    bytes32[] private messages;
+contract ZeekMessages {
+    string[] private messages;
 
     // Event to acknowledge a new message
     event MessageReceived(string);
@@ -12,10 +12,8 @@ contract ZeekSecretMessages {
         emit MessageReceived("Zeek welcomes you to zkSync!");
     }
 
-    // Function to send a "secret" message to Zeek
     function sendMessage(string memory _message) public {
-        bytes32 hashedMessage = keccak256(abi.encodePacked(_message));
-        messages.push(hashedMessage);
+        messages.push(_message);
 
         // Acknowledge the message receipt with Zeek's reply
         emit MessageReceived("ZK is the endgame - Message received!");
@@ -25,4 +23,10 @@ contract ZeekSecretMessages {
     function getTotalMessages() public view returns (uint) {
         return messages.length;
     }
+
+    // Function to return the last message sent to Zeek
+    function getLastMessage() public view returns (string memory) {
+        require(messages.length > 0, "No messages sent to Zeek yet!");
+        return messages[messages.length - 1];
+    }
 }

scripts/paymaster-transaction.ts

@@ -1,43 +1,126 @@
-
 import {ethers} from "ethers";
+import {Provider, Contract, utils, Signer} from "zksync-ethers";
 
+// Address of the ZeekMessages contract
+const ZEEK_MESSAGES_CONTRACT_ADDRESS = "";
 // Address of the ERC20 token contract
-const TOKEN_CONTRACT_ADDRESS = ""
-// Wallet that will receive tokens
-const RECEIVER_WALLET    = "";
-// Amount of tokens to mint in ETH format, e.g. 1.23
-const TOKEN_AMOUNT    = "";
+const TOKEN_CONTRACT_ADDRESS = "";
+// Message to be sent to the contract
+const NEW_MESSAGE = "This tx cost me no ETH!";
 
 (async () => {
   try {
 
 // Note that the script needs the ABI which is generated from the compilation artifact.
   // Make sure contract is compiled and artifacts are generated
-  const artifactsPath = `browser/contracts/artifacts/TestToken.json` // Change this for different path
-  console.log(artifactsPath)
+  const messagesContractArtifactsPath = `browser/contracts/artifacts/ZeekSecretMessages.json`;
+  const tokenContractArtifactsPath = `browser/contracts/artifacts/TestToken.json`;
+
+  const messagesContractABI = JSON.parse(await remix.call('fileManager', 'getFile', messagesContractArtifactsPath));
+  const tokenContractABI = JSON.parse(await remix.call('fileManager', 'getFile', tokenContractArtifactsPath));
+
+  console.log('Sending a transaction via the testnet paymaster')
+
+  const browserProvider = new ethers.providers.Web3Provider(web3Provider)
+
+  const zkProvider = new Provider("https://sepolia.era.zksync.dev");
+
+  // const signer = (new ethers.providers.Web3Provider(web3Provider)).getSigner(0)
+  const zkSigner = Signer.from(browserProvider.getSigner(), zkProvider);
+
+  // const walletAddress = await signer.getAddress();
+  const walletAddress = await zkSigner.getAddress();
+
+  console.log(walletAddress)
+
+  // initialise messages and token contracts with address, abi and signer
+  const messagesContract= new Contract(ZEEK_MESSAGES_CONTRACT_ADDRESS, messagesContractABI.abi, zkSigner);
+  const tokenContract= new Contract(TOKEN_CONTRACT_ADDRESS, tokenContractABI.abi, zkSigner);
+
+// retrieve and print the current balance of the wallet
+  let ethBalance = await zkProvider.getBalance(walletAddress)
+  console.log(`Account ${walletAddress} has ${ethers.utils.formatEther(ethBalance)} ETH`);
+  let tokenBalance = await tokenContract.balanceOf(walletAddress)
+  console.log(`Account ${walletAddress} has ${ethers.utils.formatUnits(tokenBalance, 18)} tokens`);
 
-  const metadata = JSON.parse(await remix.call('fileManager', 'getFile', artifactsPath))
 
+// retrieve the testnet paymaster address
+  const testnetPaymasterAddress = await zkProvider.getTestnetPaymasterAddress();
 
-  const signer = (new ethers.providers.Web3Provider(web3Provider)).getSigner(0)
+  console.log(`Testnet paymaster address is ${testnetPaymasterAddress}`);
 
+  const gasPrice = await zkProvider.getGasPrice();
 
-  // initialise token contract with address, abi and signer
-  const tokenContract= new ethers.Contract(TOKEN_CONTRACT_ADDRESS, metadata.abi, signer);
+  console.log("gasPrice >> ", gasPrice)
+
+  // define paymaster parameters for gas estimation
+  const paramsForFeeEstimation = utils.getPaymasterParams(testnetPaymasterAddress, {
+    type: "ApprovalBased",
+    token: TOKEN_CONTRACT_ADDRESS,
+    // set minimalAllowance to 1 for estimation
+    minimalAllowance: ethers.BigNumber.from(1),
+    // empty bytes as testnet paymaster does not use innerInput
+    innerInput: new Uint8Array(0),
+  });
+
+  // estimate gasLimit via paymaster
+  const gasLimit = await messagesContract.estimateGas.sendMessage(NEW_MESSAGE, {
+    customData: {
+      gasPerPubdata: utils.DEFAULT_GAS_PER_PUBDATA_LIMIT,
+      paymasterParams: paramsForFeeEstimation,
+    },
+  });
+
+  console.log("gasLimit >> ", gasLimit)
+
+
+  // fee calculated in ETH will be the same in
+  // ERC20 token using the testnet paymaster
+  const fee = gasPrice * gasLimit;
+
+  console.log("Fee >>", fee);
+
+  // new paymaster params with fee as minimalAllowance
+  const paymasterParams = utils.getPaymasterParams(testnetPaymasterAddress, {
+    type: "ApprovalBased",
+    token: TOKEN_CONTRACT_ADDRESS,
+    // provide estimated fee as allowance
+    minimalAllowance: fee,
+    // empty bytes as testnet paymaster does not use innerInput
+    innerInput: new Uint8Array(0),
+  });
+
+  // full overrides object including maxFeePerGas and maxPriorityFeePerGas
+  const txOverrides = {
+    maxFeePerGas: gasPrice,
+    maxPriorityFeePerGas: "1",
+    gasLimit,
+    customData: {
+      gasPerPubdata: utils.DEFAULT_GAS_PER_PUBDATA_LIMIT,
+      paymasterParams,
+    }
+  }
 
-  console.log("Minting tokens...");
-  const tx = await tokenContract.mint(RECEIVER_WALLET, ethers.utils.parseEther(TOKEN_AMOUNT));
-  console.log(`Mint transaction is ${tx.hash}`)
-  await tx.wait();
-  console.log("Success!");
+  console.log("overrides >> ", txOverrides);
 
+  console.log(`Sign the transaction in your wallet`);
 
-  const balance = await tokenContract.balanceOf(RECEIVER_WALLET)
+  // send transaction with additional paymaster params as overrides
+  const txHandle = await messagesContract.sendMessage(NEW_MESSAGE, txOverrides);
+  console.log(`Transaction ${txHandle.hash} with fee ${ethers.utils.formatUnits(fee, 18)} ERC20 tokens, sent via paymaster ${testnetPaymasterAddress}`);
+  await txHandle.wait();
+  console.log(`Transaction processed`)
 
+  ethBalance = await zkProvider.getBalance(walletAddress)
+  tokenBalance = await tokenContract.balanceOf(walletAddress)
+  console.log(`Account ${walletAddress} now has ${ethers.utils.formatEther(ethBalance)} ETH`);
+  console.log(`Account ${walletAddress} now has ${ethers.utils.formatUnits(tokenBalance, 18)} tokens`);
 
-  console.log(`The account ${RECEIVER_WALLET} now has ${balance} tokens`)
+  console.log(`Done!`);
 
   } catch (e) {
-    console.log(e.message)
+    console.error('Error in script!')
+    console.error(e.message)
+    console.error(e)
   }
 })()