evm-puzzles VS openzeppelin-contracts

More EVM Puzzles are a collection of puzzles, similar to EVM Puzzles by Franco Victorio. In each puzzle, the objective is to have the code STOP, rather than REVERT.

Try these puzzles! If you can solve them all, you will be in a solid place for evm skills https://github.com/fvictorio/evm-puzzles

EVM Puzzles are a collection of puzzles by Franco Victorio. In this Markdown file, I wrote down the walkthrough for each of them.

I understand reentrancy. These vulnerabilities are rare today as they are very simple. You'll want a lot of experience developing complex smart contracts and learning EVM internals. Try solving these puzzles - once you can solve them confidently, you will be in a good spot on your fundamentals! https://github.com/fvictorio/evm-puzzles

EVM Puzzles

// SPDX-License-Identifier: GPL-3.0 pragma solidity ^0.8.20; import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v5.0.0/contracts/token/ERC20/ERC20.sol"; interface Sfs {     function register(address _recipient) external returns (uint256 tokenId); } contract ModeToken is ERC20 {     address feeReceiver = msg.sender;     constructor() ERC20("ModeTokenSFSTest", "SFST2") { //Example amount to mint our ERC20         _mint(msg.sender, 1000 10 * 18);   // This is the SFS contract address on testnet Sfs sfsContract = Sfs(0xBBd707815a7F7eb6897C7686274AFabd7B579Ff6); //Registers this contract and assigns the NFT //to the deployer of this contract sfsContract.register(msg.sender);     } }

Lets look the events of Open Zeppelin’s ERC20 token contract:

ERC-777 is difficult to implement properly, due to its susceptibility to different forms of attack(opens in a new tab). It is recommended to use ERC-20 instead. This page remains as a historical archive.