add contracts

.gitmodules

@@ -1,3 +1,6 @@
 [submodule "lib/forge-std"]
 	path = lib/forge-std
 	url = https://github.com/foundry-rs/forge-std
+[submodule "lib/openzeppelin-contracts"]
+	path = lib/openzeppelin-contracts
+	url = https://github.com/OpenZeppelin/openzeppelin-contracts

env.example

@@ -0,0 +1,3 @@
+SEPOLIA_RPC_URL=
+ETHERSCAN_API_KEY=
+ACCOUNT=

makefile

@@ -0,0 +1,12 @@
+-include .env
+
+ANVIL_PRIVATE_KEY := 0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80
+
+NETWORK_ARGS := --rpc-url http://localhost:8545 --private-key $(ANVIL_PRIVATE_KEY) --broadcast
+
+ifeq ($(findstring --network sepolia,$(ARGS)),--network sepolia)
+	NETWORK_ARGS := --rpc-url $(SEPOLIA_RPC_URL) --account $(ACCOUNT) --broadcast --verify --etherscan-api-key $(ETHERSCAN_API_KEY) -vvvv
+endif
+
+deploy:
+	@forge script script/DeployMyToken.s.sol:DeployMyToken $(NETWORK_ARGS)

script/DeployMyToken.s.sol

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.26;
+
+import {Script} from "forge-std/Script.sol";
+import {MyToken} from "src/MyToken.sol";
+
+contract DeployMyToken is Script {
+    uint256 public constant INITIAL_SUPPLY = 10000 ether;
+
+    function run() external returns (MyToken) {
+        vm.startBroadcast();
+        MyToken myToken = new MyToken(INITIAL_SUPPLY);
+        vm.stopBroadcast();
+        return myToken;
+    }
+}

src/MyToken.sol

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.26;
+
+import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+
+contract MyToken is ERC20 {
+    constructor(uint256 initialSupply) ERC20("My Token", "MTK") {
+        _mint(msg.sender, initialSupply);
+    }
+}

test/MyTokenTest.t.sol

@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.26;
+
+import {Test} from "forge-std/Test.sol";
+import {MyToken} from "src/MyToken.sol";
+import {DeployMyToken} from "script/DeployMyToken.s.sol";
+import {IERC20Errors} from "@openzeppelin/contracts/interfaces/draft-IERC6093.sol";
+
+contract MyTokenTest is Test {
+    MyToken myToken;
+    DeployMyToken deployer;
+    uint256 public constant INITIAL_SUPPLY = 10000 ether;
+    address public constant USER = address(1);
+    address public constant SPENDER = address(2);
+
+    function setUp() external {
+        deployer = new DeployMyToken();
+        myToken = deployer.run();
+    }
+
+    function test_setUp() public view {
+        assertEq(myToken.balanceOf(msg.sender), INITIAL_SUPPLY);
+    }
+
+    // Direct transfer
+    function test_transfer() public {
+        uint256 balSenderBefore = myToken.balanceOf(msg.sender);
+        uint256 balUserBefore = myToken.balanceOf(USER);
+        uint256 transferAmount = 10 ether;
+
+        vm.prank(msg.sender);
+        myToken.transfer(USER, transferAmount);
+
+        uint256 balSenderAfter = myToken.balanceOf(msg.sender);
+        uint256 balUserAfter = myToken.balanceOf(USER);
+
+        assertEq(balSenderAfter, balSenderBefore - transferAmount);
+        assertEq(balUserAfter, balUserBefore + transferAmount);
+    }
+
+    // Indirect transfer
+    function test_transferFrom() public {
+        uint256 balSenderBefore = myToken.balanceOf(msg.sender);
+        uint256 balUserBefore = myToken.balanceOf(USER);
+        uint256 transferAmount = 10 ether;
+
+        // Revert if not approve
+        vm.expectRevert(
+            abi.encodeWithSelector(IERC20Errors.ERC20InsufficientAllowance.selector, SPENDER, 0, transferAmount)
+        );
+        vm.prank(SPENDER);
+        myToken.transferFrom(msg.sender, USER, transferAmount);
+
+        // Actual Transactions
+        vm.prank(msg.sender);
+        myToken.approve(SPENDER, transferAmount);
+
+        vm.prank(SPENDER);
+        myToken.transferFrom(msg.sender, USER, transferAmount);
+
+        uint256 balSenderAfter = myToken.balanceOf(msg.sender);
+        uint256 balUserAfter = myToken.balanceOf(USER);
+
+        assertEq(balSenderAfter, balSenderBefore - transferAmount);
+        assertEq(balUserAfter, balUserBefore + transferAmount);
+    }
+}