whitelist contract complete code

hardhat-tutorial/.gitignore

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+node_modules
+.env
+coverage
+coverage.json
+typechain
+
+#Hardhat files
+cache
+artifacts

hardhat-tutorial/README.md

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+# steps to compile and deploy
+
+1. npx hardhat compile
+2. npx hardhat run scripts/deploy.js --network rinkeby

hardhat-tutorial/contracts/Whitelist.sol

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+//SPDX-License-Identifier: Unlicense
+pragma solidity ^0.8.0;
+
+contract Whitelist {
+    uint8 public maxWhitelistedAddresses;
+
+    uint8 public numAddressesWhitelisted;
+
+    mapping(address => bool) public whitelistedAddresses;
+
+    constructor(uint8 _maxWhitelistedAddresses) {
+        maxWhitelistedAddresses = _maxWhitelistedAddresses;
+    }
+
+    function addToWhitelist() public {
+        require(
+            !whitelistedAddresses[msg.sender],
+            "Sender has already been whitelisted"
+        );
+        require(
+            numAddressesWhitelisted < maxWhitelistedAddresses,
+            "More addresses cant be added, limit reached"
+        );
+        whitelistedAddresses[msg.sender] = true;
+        numAddressesWhitelisted += 1;
+    }
+}

hardhat-tutorial/hardhat.config.js

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+require("@nomiclabs/hardhat-waffle");
+
+require("dotenv").config({ path: ".env" });
+
+const ALCHEMY_API_KEY_URL = process.env.ALCHEMY_API_KEY_URL;
+
+const RINKEBY_PRIVATE_KEY = process.env.RINKEBY_PRIVATE_KEY;
+
+module.exports = {
+  solidity: "0.8.4",
+  networks: {
+    rinkeby: {
+      url: ALCHEMY_API_KEY_URL,
+      accounts: [RINKEBY_PRIVATE_KEY],
+    },
+  },
+};