📂 Portfolio of smart contracts 📌

This repository is a portfolio of different smart contract implementations, like ERC token standards and others smart contract applications based on open source tutorials.

💎 Tokens

This section focuses on implementation, from scratch, of different token standards, including fungible and non-fungible tokens like ERC20 and ERC721.

Directory tokens/contracts/tokens contains following contracts:

• BasicErc20 token is an ERC20 token with minimal functionality of the standard
• MetaErc20 token is an ERC20 token with additional metadata like: name, symbol and decimals fields
• MintableErc20 token is an ERC20 token that total supply can by changed by minting or burning the tokens
• BasicErc223 is a token based of EIP223 which protects against accidentally token burning by sending to wrong contract address
• BasicErc677 applies transferAndCall mechanism based on EIP677, which reduces service usage ERC20 token payment from 2 transaction, approve and transferFrom, to single one. More detailed explanation can be found in article Ethereum smart service payment with tokens
• Erc721 is a NTF token based on EIP721 standard

⛓️ freeCodeCamp/Chainlink tutorial

In free-code-camp directory there are projects based on tutorial https://www.youtube.com/watch?v=M576WGiDBdQ. There are a following projects:

• web3.py located in free-code-camp/web3 catalogue which is focused on deploying and testing SimpleStorage by using web3.py library
• FoundMe is simple funding contract using chainlink price feed
• Lottery is simple lottery using chainlink VRF to find random winner
• proxy pattern contracts, located in free-code-camp/contracts/proxy, relayed on Openzeppelin TransparentUpgradeableProxy support
• TokenFarm is simple yield farming based on 3 ERC20 tokens used for staking and one ERC20 token used as a reward token returns when unstake is call

🏗 Scaffold-ETH challenges

This section is based on scaffold eth challenges. There are implemented following ones:

• in scaffold-challenges/contracts/staking are contracts for decentralized staking challenge
• in scaffold-challenges/contracts/vendor_token are contracts for token vendor challenge
• in scaffold-challenges/contracts/dex there is simple DEX based on product AMM
• RandomGenerator is a contract of random number generator based on commit reveal pattern. In case of trouble shoot in test suite, run tests again
• Multisig is a contract implementing multi signature wallet N of M, which requires N signers from M allowed signer to transfer Eth to destination address

↔️ Proxy contracts

This section covers implementation of proxy contract, which allows for future contract upgrades of bug fixing. Code, located in proxy-pattern/contracts relays on following article Upgradeable proxy contract from scratch

🛠️ How to run

• install ganache-cli version 6.12.2
• install brownie version 1.18.1
• choose project directory and run brownie test inside it
• 🆕 optional blockscout explorer can by used to view what happen on chain, it's enough to up and run explorer and set BLOCKSCOUT_PUBLISH=true env e.g in .env file

📜 TODO List

• implement ERC777 standard
• implement ERC1155 standard
• implement ERC721Enumerable interface