lucasfernandes

/**
 * ANSWER 4:
 * While the question references `web3.js`, I typically prefer using `ethers.js`
 * for frontend interactions due to its cleaner API, better modularity, and superior developer experience.
 *
 * When implementing real-time staking balance and rewards updates, the first thing I consider is:
 * 
 * 👉 **Is there a subgraph (The Graph) available?**
 * 
 * If yes, I always prefer querying the subgraph via GraphQL — it's efficient, fast, and offloads logic from the frontend.

lucasfernandes

/**
 * ANSWER 3:
 * BEP-20 tokens follow the same interface as ERC-20 (EVM standard).
 * To interact with a BEP-20 token, I use the standard ERC-20 interface,
 * or preferably the `SafeERC20` wrapper from OpenZeppelin to improve safety.
 *
 * Key functions used to interact with the token contract:
 *
 * - `transferFrom(address from, address to, uint256 amount)` — for staking

lucasfernandes

/**
  ANSWER 2:
  Reentrancy is a type of attack where an external contract repeatedly calls back into a vulnerable function 
  before the previous execution is completed. This can be exploited to manipulate the contract's state 
  or drain its funds.

  To prevent this, we can use the `ReentrancyGuard` contract from OpenZeppelin and apply its `nonReentrant` modifier.
*/

// SPDX-License-Identifier: UNLICENSED

lucasfernandes

/**
  ANSWER 1:
  In order to enforce lock-up periods, I typically use a staking info struct that 
  stores details of each user stake, including the timestamp when they staked.
  Then, in the withdraw function, I check whether the lock-up period has passed 
  using a `require` statement, like this:
*/

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.28;

lucasfernandes

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.28;

import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
import {Pausable} from "@openzeppelin/contracts/utils/Pausable.sol";
import {ReentrancyGuard} from "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
import {IVesting} from "./interfaces/IVesting.sol";
import {ISamuraiTiers} from "./interfaces/ISamuraiTiers.sol";

lucasfernandes

// SPDX-License-Identifier: UNLINCENSED
pragma solidity 0.8.28;

import {Script} from "forge-std/Script.sol";
import {Vesting} from "../src/Vesting.sol";
import {IVesting} from "../src/interfaces/IVesting.sol";
import {console} from "forge-std/console.sol";
import {SamuraiTiers} from "../src/SamuraiTiers.sol";
import {ISamuraiTiers} from "../src/interfaces/ISamuraiTiers.sol";
import {ERC20Mock} from "../src/mocks/ERC20Mock.sol";

lucasfernandes

// MyContract constructor
constructor(address,uint256,MyInterface.MyStruct[] memory,bool,bool)

// Script used in deploy
function run() external returns (MyContract myContract) {
    address someAddress = 0x...;
    uint256 totalMax = 100_000 ether;

    MyInterface.MyStruct[] memory strs = new MyInterface.MyStruct[](6);

lucasfernandes

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.20;

import "forge-std/Script.sol";
import "../src/Sam.sol";

contract SamScript is Script {
    function run() public {
        uint256 deployerPrivateKey = vm.envUint("PRIVATE_KEY");

lucasfernandes

extension CharacterSet {
    static let vowels = CharacterSet(charactersIn: "aeiou")
    static let consonants = CharacterSet.letters.subtracting(vowels)
}

extension String {
    
    var specialChars: String {
        self
            .components(separatedBy: .punctuationCharacters)

lucasfernandes

curl https://api.github.com/authorizations --user lucasfernandes --header "X-GitHub-OTP: 921217"