update: aula 2

smartcontracts/src/Counter.sol

@@ -17,7 +17,6 @@ contract Counter {
         number++;
     }
 
-
     function getError(uint256 yourAmount) public pure returns (string memory) {
         revert CustomError("An error occurred", yourAmount);
     }

smartcontracts/src/ERC20.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.18;
+
+import {IERC20} from "./IERC20.sol";
+
+contract ERC20 is IERC20 {}

smartcontracts/src/IERC20.sol

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.18;
+
+interface IERC20 {
+    function symbol() external returns (string memory);
+    function name() external returns (string memory);
+    function decimals() external returns (uint8);
+
+    function allowance(address owner, address spender) external view returns (uint256);
+    function balanceOf(address account) external view returns (uint256);
+    function totalSupply() external view returns (uint256);
+
+    function transferFrom(address _from, address _to, uint256 _value) external returns (bool success);
+    function transfer(address recipient, uint256 amount) external returns (bool);
+    function approve(address spender, uint256 amount) external returns (bool);
+
+    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
+    event Transfer(address indexed _from, address indexed _to, uint256 _value);
+}

smartcontracts/src/Token.sol

@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.18;

smartcontracts/test/Token.t.sol

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.18;
+
+import {BaseSetup} from "./BaseSetup.t.sol";
+
+contract TokenTest is BaseSetup {
+    function setUp() public override {
+        BaseSetup.setUp();
+    }
+}

smartcontracts/test/Utils.t.sol

@@ -6,15 +6,12 @@ import {Test} from "forge-std/Test.sol";
 import {Vm} from "forge-std/Vm.sol";
 
 contract Utils is Test {
-    string mnemonic =
-        "test test test test test test test test test test test junk";
+    string mnemonic = "test test test test test test test test test test test junk";
 
-    function createUsers(
-        uint32 userNum
-    ) public returns (address payable[] memory) {
+    function createUsers(uint32 userNum) public returns (address payable[] memory) {
         address payable[] memory users = new address payable[](userNum);
         for (uint32 i = 0; i < userNum; i++) {
-            (address user, ) = deriveRememberKey(mnemonic, i);
+            (address user,) = deriveRememberKey(mnemonic, i);
             vm.deal(user, 10000 ether);
             users[i] = payable(user);
         }