Submitted week 4 assignment

contracts/MyNFT.sol

@@ -1,26 +1,26 @@
-// Contract based on https://docs.openzeppelin.com/contracts/4.x/erc721
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
-import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
-import "@openzeppelin/contracts/utils/Counters.sol";
+import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
+import "@openzeppelin/contracts/access/Ownable.sol";
 
-contract MyNFT is ERC721URIStorage {
-    using Counters for Counters.Counter;
-    Counters.Counter private _tokenIds;
+contract MyNFT is ERC721, Ownable {
+    uint256 private _tokenIdCounter;
 
-    constructor() ERC721("MyNFT", "MNFT") {}
-
-    function mintNFT(address recipient, string memory tokenURI)
-    public
-    returns (uint256)
-    {
-        _tokenIds.increment();
-
-        uint256 newItemId = _tokenIds.current();
-        _mint(recipient, newItemId);
-        _setTokenURI(newItemId, tokenURI);
+    constructor() ERC721("MyNFT", "MNFT") Ownable(msg.sender) {
+        _tokenIdCounter = 0;
+    }
 
+    function mintNFT(address recipient) public onlyOwner returns (uint256) {
+        require(recipient != address(0), "Cannot mint to zero address");
+
+        uint256 newItemId = _tokenIdCounter + 1;
+        _tokenIdCounter = newItemId;
+        _safeMint(recipient, newItemId);
         return newItemId;
     }
+
+    function getCurrentCounter() public view returns (uint256) {
+        return _tokenIdCounter;
+    }
 }

gitignore.txt

@@ -0,0 +1,17 @@
+node_modules
+.env
+
+# Hardhat files
+/cache
+/artifacts
+
+# TypeChain files
+/typechain
+/typechain-types
+
+# solidity-coverage files
+/coverage
+/coverage.json
+
+# Hardhat Ignition default folder for deployments against a local node
+ignition/deployments/chain-31337

hardhat.config.ts

@@ -1,24 +1,32 @@
-import("@nomiclabs/hardhat-ethers");
-import("@nomiclabs/hardhat-waffle");
-import dotenv from "dotenv";
+import { HardhatUserConfig } from 'hardhat/config';
+import '@nomicfoundation/hardhat-toolbox';
+import * as dotenv from 'dotenv';
+import './tasks/nft';
 
-const argv = JSON.parse(env("npm_config_argv"));
-if (argv.original !== ["hardhat", "test"]) {
-  require('dotenv').config();
-}
+dotenv.config();
 
-import("./tasks/nft");
-
-import { HardhatUserConfig } from "hardhat/config";
+const ALCHEMY_API_KEY = process.env.ALCHEMY_API_KEY || '';
+const PRIVATE_KEY = process.env.PRIVATE_KEY || '';
 
 const config: HardhatUserConfig = {
-  solidity: "0.8.0",
+  solidity: {
+    version: '0.8.27',
+    settings: {
+      optimizer: {
+        enabled: true,
+        runs: 200,
+      },
+    },
+  },
   networks: {
     sepolia: {
-      url: `https://eth-sepolia.alchemyapi.io/v2/${process.env.ALCHEMY_API_KEY}`,
-      accounts: [process.env.ETH_PRIVATE_KEY],
+      url: `https://eth-sepolia.g.alchemy.com/v2/${ALCHEMY_API_KEY}`,
+      accounts: PRIVATE_KEY ? [PRIVATE_KEY] : [],
     },
   },
+  etherscan: {
+    apiKey: process.env.ETHERSCAN_API_KEY || '',
+  },
 };
 
 export default config;

library/contract.ts

@@ -0,0 +1,18 @@
+import { Contract, ethers } from "ethers"; 
+import { HardhatRuntimeEnvironment } from "hardhat/types";
+
+import { env } from "./env"; 
+import { getProvider } from "./provider";
+
+export async function getContract(
+  name: string,
+  hre: HardhatRuntimeEnvironment
+): Promise<Contract> {
+
+  const WALLET = new ethers.Wallet(env("ETH_PRIVATE_KEY"), getProvider());
+
+  const contract = await hre.ethers.getContractAt(name, env("NFT_CONTRACT_ADDRESS"), WALLET);
+
+  return contract;
+}
+

library/env.ts

@@ -0,0 +1,7 @@
+export function env(key: string): string {
+    const value = process.env[key];
+    if (value === undefined) {
+      throw `${key} is undefined`;
+    }
+    return value;
+  }  

library/provider.ts

@@ -0,0 +1,7 @@
+import { ethers } from "ethers";
+
+export function getProvider(): ethers.Provider {
+  return ethers.getDefaultProvider("ropsten", {
+    alchemy: process.env.ALCHEMY_API_KEY,
+  });
+}

library/wallet.ts

@@ -0,0 +1,7 @@
+import { ethers } from "ethers";
+import { env } from "./env";
+import { getProvider } from "./provider";
+
+export function getWallet(): ethers.Wallet {
+  return new ethers.Wallet(env("ETH_PRIVATE_KEY"), getProvider());
+}