feat: add erc20 paymaster

.vscode/launch.json

@@ -0,0 +1,16 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+      {
+        "type": "node",
+        "request": "launch",
+        "name": "Launch Hardhat Test",
+        "program": "${workspaceFolder}/contracts/node_modules/.bin/hardhat",
+        "args": ["test", "--network", "localNode"],
+        "cwd": "${workspaceFolder}/contracts",
+        "console": "integratedTerminal",
+        "skipFiles": ["<node_internals>/**"]
+      }
+    ]
+  }
+

contracts/contracts/contentsign/ContentSignNFT.sol

@@ -10,21 +10,19 @@ import {AccessControl} from "@openzeppelin/contracts/access/AccessControl.sol";
 /// configurable URL
 contract ContentSignNFT is ERC721, ERC721URIStorage, AccessControl {
     bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
-    uint256 private _nextTokenId;
+    uint256 public nextTokenId;
 
     constructor(string memory name, string memory symbol, address admin) ERC721(name, symbol) {
         _grantRole(DEFAULT_ADMIN_ROLE, admin);
         _grantRole(MINTER_ROLE, admin);
     }
 
     function safeMint(address to, string memory uri) public onlyRole(MINTER_ROLE) {
-        uint256 tokenId = _nextTokenId++;
+        uint256 tokenId = nextTokenId++;
         _safeMint(to, tokenId);
         _setTokenURI(tokenId, uri);
     }
 
-    // The following functions are overrides required by Solidity.
-
     function tokenURI(uint256 tokenId)
         public
         view

contracts/contracts/paymasters/BasePaymaster.sol

@@ -43,8 +43,6 @@ abstract contract BasePaymaster is IPaymaster, AccessControl {
     {
         // By default we consider the transaction as accepted.
         magic = PAYMASTER_VALIDATION_SUCCESS_MAGIC;
-        // By default no context will be returned unless the paymaster flow requires a post transaction call.
-        context = new bytes(0);
 
         if (transaction.paymasterInput.length < 4) {
             revert InvalidPaymasterInput("The standard paymaster input must be at least 4 bytes long");
@@ -65,7 +63,7 @@ abstract contract BasePaymaster is IPaymaster, AccessControl {
         } else if (
             paymasterInputSelector == IPaymasterFlow.approvalBased.selector
         ) {
-            (address token, uint256 amount, bytes memory data) = abi.decode(
+            (address token, uint256 minimalAllowance, bytes memory data) = abi.decode(
                 transaction.paymasterInput[4:],
                 (address, uint256, bytes)
             );
@@ -74,7 +72,7 @@ abstract contract BasePaymaster is IPaymaster, AccessControl {
                 userAddress,
                 destAddress,
                 token,
-                amount,
+                minimalAllowance,
                 data,
                 requiredETH
             );

contracts/contracts/paymasters/Erc20Paymaster.sol

@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+
+import {BasePaymaster} from "./BasePaymaster.sol";
+
+contract Erc20Paymaster is BasePaymaster {
+    bytes32 public constant PRICE_ORACLE_ROLE = keccak256("PRICE_ORACLE_ROLE");
+
+    uint256 public feePrice;
+    address public allowedToken;
+
+    error AllowanceNotEnough(uint256 provided, uint256 required);
+    error FeeTransferFailed(bytes reason);
+    error TokenNotAllowed();
+
+    constructor(address admin, address priceOracle, address erc20, uint256 initialFeePrice) BasePaymaster(admin, admin) {
+        _grantRole(PRICE_ORACLE_ROLE, priceOracle);
+        allowedToken = erc20;
+        feePrice = initialFeePrice;
+    }
+
+    function grantPriceOracleRole(address oracle) public onlyRole(DEFAULT_ADMIN_ROLE) {
+        _grantRole(PRICE_ORACLE_ROLE, oracle);
+    }
+
+    function revokePriceOracleRole(address oracle) public onlyRole(DEFAULT_ADMIN_ROLE) {
+        _revokeRole(PRICE_ORACLE_ROLE, oracle);
+    }
+
+    function updateFeePrice(uint256 newFeePrice) public onlyRole(PRICE_ORACLE_ROLE) {
+        feePrice = newFeePrice;
+    }
+
+    function _validateAndPayGeneralFlow(
+        address /* from */,
+        address /* to */,
+        uint256 /* requiredETH */
+    ) internal pure override {
+        revert PaymasterFlowNotSupported();
+    }
+
+    function _validateAndPayApprovalBasedFlow(
+        address userAddress,
+        address /* destAddress */,
+        address token,
+        uint256 amount,
+        bytes memory /* data */,
+        uint256 requiredETH
+    ) internal override {
+
+        if (token != allowedToken) {
+            revert TokenNotAllowed();
+        }
+
+        address thisAddress = address(this);
+
+        uint256 providedAllowance = IERC20(token).allowance(
+            userAddress,
+            thisAddress
+        );
+
+        uint256 requiredToken = requiredETH * feePrice;
+
+        if (providedAllowance < requiredToken) {
+            revert AllowanceNotEnough(providedAllowance, requiredToken);
+        }
+
+        try 
+            IERC20(token).transferFrom(userAddress, thisAddress, requiredToken)
+        {
+            return;
+        } catch (bytes memory revertReason) {
+            revert FeeTransferFailed(revertReason);
+        }
+    }
+}

contracts/deploy/deploy.ts

@@ -2,11 +2,16 @@ import { deployContract, getGovernance, getWhitelistAdmin } from "./utils";
 import { execSync } from "child_process";
 
 export default async function() {
-    await deployContract("NODL", [getGovernance(), getGovernance()]);
+    const nodl = await deployContract("NODL", [getGovernance(), getGovernance()]);
+    const nodlAddress = await nodl.getAddress();
 
     const nft = await deployContract("ContentSignNFT", ["Click", "CLK", getWhitelistAdmin()]);
     const nftAddress = await nft.getAddress();
-    await deployContract("WhitelistPaymaster", [getGovernance(), getWhitelistAdmin(), [await nft.getAddress()]]);
+    await deployContract("WhitelistPaymaster", [getGovernance(), getWhitelistAdmin(), [nftAddress]]);
+
+    const initialFeePrice = 1; // Means 1 nodl per 1 wei
+    const priceOracle = getWhitelistAdmin(); // For now we assume that the whitelist admin is the same as the price oracle for NODL paymaster
+    const paymasterContract = await deployContract("Erc20Paymaster", [getGovernance(), priceOracle, nodlAddress, initialFeePrice]);
 
     // used for docker compose setup so we can deploy a The Graph indexer on the NFT contract
     execSync(`echo "${nftAddress}" > .nft-contract-address`);

contracts/deploy/utils.ts

@@ -1,8 +1,8 @@
 import { Provider, Wallet } from "zksync-ethers";
 import * as hre from "hardhat";
+import { ethers } from "ethers";
 import { Deployer } from "@matterlabs/hardhat-zksync-deploy";
 import dotenv from "dotenv";
-import { BigNumberish, formatEther } from "ethers";
 
 import "@matterlabs/hardhat-zksync-node/dist/type-extensions";
 import "@matterlabs/hardhat-zksync-verify/dist/src/type-extensions";
@@ -13,25 +13,19 @@ dotenv.config();
 export const getProvider = () => {
   const rpcUrl = hre.network.config.url;
   if (!rpcUrl) throw `⛔️ RPC URL wasn't found in "${hre.network.name}"! Please add a "url" field to the network config in hardhat.config.ts`;
+  return new Provider(rpcUrl);;
+}
 
-  // Initialize zkSync Provider
-  const provider = new Provider(rpcUrl);
-
-  return provider;
+export const getEthProvider = () => {
+  return hre.network.config.ethNetwork ?? ethers.getDefaultProvider(hre.network.config.ethNetwork);
 }
 
 export const getWallet = (privateKey?: string) => {
   if (!privateKey) {
-    // Get wallet private key from .env file
-    if (!process.env.WALLET_PRIVATE_KEY) throw "⛔️ Wallet private key wasn't found in .env file!";
+    const randomWallet = Wallet.createRandom();
+    return new Wallet(randomWallet.privateKey, getProvider(), getEthProvider());
   }
-
-  const provider = getProvider();
-
-  // Initialize zkSync Wallet
-  const wallet = new Wallet(privateKey ?? process.env.WALLET_PRIVATE_KEY!, provider);
-
-  return wallet;
+  return new Wallet(privateKey ?? process.env.WALLET_PRIVATE_KEY!, getProvider(), getEthProvider());
 }
 
 export const getGovernance = () => {
@@ -47,7 +41,7 @@ export const getWhitelistAdmin = () => {
 export const verifyEnoughBalance = async (wallet: Wallet, amount: bigint) => {
   // Check if the wallet has enough balance
   const balance = await wallet.getBalance();
-  if (balance < amount) throw `⛔️ Wallet balance is too low! Required ${formatEther(amount)} ETH, but current ${wallet.address} balance is ${formatEther(balance)} ETH`;
+  if (balance < amount) throw `⛔️ Wallet balance is too low! Required ${ethers.formatEther(amount)} ETH, but current ${wallet.address} balance is ${ethers.formatEther(balance)} ETH`;
 }
 
 /**
@@ -86,7 +80,7 @@ type DeployContractOptions = {
    */
   skipChecks?: boolean
 }
-export const deployContract = async (contractArtifactName: string, constructorArguments?: any[], options?: DeployContractOptions) => {
+export const deployContract = async (contractArtifactName: string, constructorArguments?: any[], options?: DeployContractOptions, nonce?: number) => {
   const log = (message: string) => {
     if (!options?.silent) console.log(message);
   }
@@ -107,13 +101,13 @@ export const deployContract = async (contractArtifactName: string, constructorAr
   if (!options?.skipChecks) {
     const deploymentFee = await deployer.estimateDeployFee(artifact, constructorArguments || []);
 
-    log(`Estimated total deployment cost: ${formatEther(deploymentFee)} ETH`)
+    log(`Estimated total deployment cost: ${ethers.formatEther(deploymentFee)} ETH`)
 
     await verifyEnoughBalance(wallet, deploymentFee);
   }
 
   // Deploy the contract to zkSync but behind a transparent proxy
-  const contract = await deployer.deploy(artifact, constructorArguments);
+  const contract = await deployer.deploy(artifact, constructorArguments, { nonce });
   await contract.waitForDeployment();
   const contractAddress = await contract.getAddress();
 
@@ -139,6 +133,19 @@ export const deployContract = async (contractArtifactName: string, constructorAr
   return contract;
 }
 
+/**
+ * Get a deployed contract given its name and address connected to the provided wallet
+ * @param name 
+ * @param address 
+ * @param wallet 
+ * @returns the specified contract
+ */
+export function getContract(name: string, address: string, wallet: Wallet) {
+  const artifact = hre.artifacts.readArtifactSync(name);
+  return new ethers.Contract(address, artifact.abi, wallet);
+}
+
+
 /**
  * Rich wallets can be used for testing purposes.
  * Available on zkSync In-memory node and Dockerized node.

contracts/hardhat.config.ts

@@ -7,7 +7,7 @@ import "@matterlabs/hardhat-zksync-deploy";
 import "@matterlabs/hardhat-zksync-verify";
 
 const config: HardhatUserConfig = {
-  defaultNetwork: "dockerizedNode",
+  defaultNetwork: "localNode",
   networks: {
     zkSyncSepoliaTestnet: {
       url: "https://sepolia.era.zksync.dev",
@@ -27,7 +27,7 @@ const config: HardhatUserConfig = {
       zksync: true,
       verifyURL: "https://zksync2-testnet-explorer.zksync.dev/contract_verification",
     },
-    dockerizedNode: {
+    localNode: {
       url: "http://localhost:3050",
       ethNetwork: "http://localhost:8545",
       zksync: true,
@@ -41,10 +41,7 @@ const config: HardhatUserConfig = {
       url: "http://zksync:3050",
       ethNetwork: "http://geth:8545",
       zksync: true,
-    },
-    hardhat: {
-      zksync: true,
-    },
+    }
   },
   zksolc: {
     version: "latest",
@@ -56,6 +53,9 @@ const config: HardhatUserConfig = {
   solidity: {
     version: "0.8.20",
   },
+  mocha: {
+    timeout: 120000 // Timeout in milliseconds
+  }
 };
 
 export default config;

contracts/package.json

@@ -6,8 +6,8 @@
     "deploy": "hardhat deploy-zksync --script deploy.ts",
     "compile": "hardhat compile",
     "clean": "hardhat clean",
-    "test": "hardhat test --network hardhat",
-    "mint": "hardhat run scripts/mint.ts --network dockerizedNode",
+    "test": "hardhat test --network localNode",
+    "mint": "hardhat run scripts/mint.ts --network localNode",
     "lint": "solhint \"contracts/**/*.sol\""
   },
   "devDependencies": {

contracts/test/paymasters/BasePaymaster.test.ts

@@ -2,7 +2,7 @@ import { expect } from 'chai';
 import { Contract, Provider, Wallet, utils } from "zksync-ethers";
 import * as ethers from "ethers";
 import { setupEnv } from './helpers';
-import { deployContract } from '../../deploy/utils';
+import { deployContract, getProvider } from '../../deploy/utils';
 
 describe("BasePaymaster", function () {
     let paymaster: Contract;
@@ -23,7 +23,8 @@ describe("BasePaymaster", function () {
         withdrawerWallet = result.withdrawerWallet;
         sponsorWallet = result.sponsorWallet;
         userWallet = result.userWallet;
-        provider = result.provider;
+
+        provider = getProvider();
 
         // using the admin or sponsor wallet to deploy seem to have us run into
         // a nonce management bug in zksync-ethers