Exploring upgradable smart contract patterns.
This mean updating a smart contract using a setter function. Ex: having a setter function to update a reward parameter inside the smart contract.
- Advantages: this is a simple solution to implement
- Disadvantages: you have to think of all the logic in your smart contract before it’s deployed Plus: who are the admins and have the right to call these functions?
This mean deploying a new smart contract an tell people to migrate from the old one to the new one
- Advantages: You don’t break the immutability promise of smart contracts. It's easier to audit.
- Disadvantages: it's a lot of effort to convince people to move
Users always interact with the same proxy. You can change the smart contract address you want your proxy to interact to using fallback function and delegate calls (which give you the power to execute target contract in the context of the calling contract!).
- Advantages: truest form of programatic upgrades. Storage variables are stored in the proxy contract and not in the implementation contract (this way, when you upgrade to a new logic contract, all the data will stay on the proxy)
- Disadvantages: subject to storage / function selector clashing
There are many proxy patterns :
- Transparent proxy pattern: admin are only allowed to call admin functions that govern the upgrades. Users can only call non admin functions (aka implementation functions)
- Universal upgradable proxies: admin functions are in the implementation contract. Gas saving, but you’re stuck once contract is deployed if you need to upgrade later.
- Diamon pattern: allow for multiple implementation contracts. Allows you to better organize your code and have more granular upgrades
This project is an implementation of Transparent proxy pattern.
yarn # Install dependencies
yarn hardhat compile # compile contracts source code
yarn hardhat node # launch local blockchain
yarn hardhat deploy --network localhost # deploy contracts on your local blockchain
yarn hardhat run ./scripts/upgradeBox.js # upgrade Box v1 solidity smart contract to Box v2!