Vault.t.sol

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.13;

import {Test, console} from "forge-std/Test.sol";
import {Vault} from "../src/Vault.sol";
import {BahlulToken} from "../src/Bahlul.sol";

/**
 * @title VaultTest
 * @notice Test suite for the Vault contract functionality
 * @dev Uses Foundry's Test framework to test deposit, withdraw, and yield distribution features
 */
contract VaultTest is Test {

    /// @notice The vault contract instance being tested
    Vault public vault;

    /// @notice Mock ERC20 token used as the underlying asset for the vault
    BahlulToken public mockERC20;

    /// @notice Test user address for simulating deposits and withdrawals
    address public user1 = makeAddr("user1");

    /// @notice Second test user address for multi-user scenarios
    address public user2 = makeAddr("user2");

    /**
     * @notice Sets up the test environment before each test
     * @dev Deploys fresh instances of BahlulToken and Vault contracts
     * Mints 1000 tokens to both test users for testing purposes
     */
    function setUp() public {
        // Deploy the mock ERC20 token
        mockERC20 = new BahlulToken();

        // Deploy the vault with the mock token as the underlying asset
        vault = new Vault(address(mockERC20));

        // Mint initial token balances to test users
        mockERC20.mint(user1, 1000);
        mockERC20.mint(user2, 1000);
    }

    /**
     * @notice Tests the basic deposit functionality of the vault
     * @dev Verifies that:
     * - User can approve and deposit tokens into the vault
     * - Token balance decreases after deposit
     * - Vault shares are minted to the depositor
     */
    function test_Deposit() public {
        // Simulate transactions from user1's perspective
        vm.startPrank(user1);

        // Approve the vault to spend user1's tokens
        mockERC20.approve(address(vault), 50);

        // Record balance before deposit
        uint256 beforeBalance = mockERC20.balanceOf(user1);
        console.log("Balance before deposit", beforeBalance);

        // Deposit 50 tokens into the vault
        vault.deposit(50);

        // Record balance after deposit (should be 50 less)
        uint256 afterBalance = mockERC20.balanceOf(user1);
        console.log("Balance after deposit", afterBalance);

        // Stop simulating user1's transactions
        vm.stopPrank();
    }

    /**
     * @notice Tests the deposit and withdraw cycle
     * @dev Verifies that:
     * - User can deposit tokens and receive shares
     * - User can withdraw by burning shares to get tokens back
     * - Balance is restored to original amount (assuming no yield distribution)
     * - The full deposit-withdraw cycle works correctly
     */
    function test_Withdraw() public {
        // Simulate transactions from user1's perspective
        vm.startPrank(user1);

        // Approve the vault to spend user1's tokens
        mockERC20.approve(address(vault), 50);

        // Record initial balance (should be 1000 from setUp)
        uint256 balanceBefore = mockERC20.balanceOf(user1);
        console.log("Balance before deposit", balanceBefore);

        // Deposit 50 tokens into the vault, receiving 50 shares (1:1 ratio for first deposit)
        vault.deposit(50);

        // Record balance after deposit (should be 950)
        uint256 balanceAfterDeposit = mockERC20.balanceOf(user1);
        console.log("Balance after deposit", balanceAfterDeposit);

        // Withdraw by burning 50 shares, should receive 50 tokens back
        vault.withdraw(50);

        // Record balance after withdrawal (should be back to 1000)
        uint256 balanceAfterWithdraw = mockERC20.balanceOf(user1);
        console.log("Balance after withdraw", balanceAfterWithdraw);

        // Stop simulating user1's transactions
        vm.stopPrank();
    }
}