hylim-tech-lover / ERC20_token

This is an ERC20 tokens which are mintable, burnable and pausable/freezable with role-based access to those functions

Upgradeable ERC20 token (MakeWorldPeace - MWP)

Introduction

This project contains UUPS upgradeable smart contract of ERC20 tokens derived from OpenZeppelin library with best practices. Besides than that, it comes with test and deploy scripts for that contract.

The ERC20 contract consists of the following functions:

• Basic ERC20 token function including minting derived from ERC20Upgradeable contract
• Maximum mint amounts of 10,000 within 3 minutes of block time
• Burnable ERC20 token function such as burn token derived from ERC20BurnableUpgradeable contract
• Pausable/Freezable ERC20 token function such as freeze or unfreeze token derived from ERC20PausableUpgradeable contract
• Upgradable feature that utilize Initializable contract and UUPSUpgradeable contract
• Owned by Gnosis Safe which is multi-signature with more security measures due to the upgradeability of smart contract.

Live Deployed Contract

All contracts shown below are deployed at Rinkeby testnet and can be traced in Etherscan as followed:

1. UUPS Proxy Contract
2. Implementation Contract V3
3. Implementation Contract V2
4. Implementation Contract V1
5. Gnosis Safe Contract

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Get started

The whole project directory can be break down into few major parts such as:

folder	Description
contracts	Folder that contains all contracts revision(s) that inherited from OpenZeppelin's templates
scripts	Script files written in JavaScript that normally used for deploying contracts to blockchain based on configuration file settings
test	Test files written in JavaScript to test contracts locally before deployed to blockchain based on test setup

Pre-requisite

• npm
• Hardhat and OpenZeppelin where their dependencies can be installed using npm install
• Create a Gnosis Safe with 1 or more Externally Owned Account(s)
• Sign up OpenZeppelin Defender and create API token for upgrading UUPS contract after passing ownership to Gnosis Safe with multi-sig
• Sign up Alchemy and create API key for Rinkeby testnet
• Sign up Etherscan and create API key to verify contract after deployed.
• Create at least 1 Metamask wallet and change to Rinkeby testnet

Configuration file

hardhat.config.js is the configuration file used by hardhat command to execute scripts stored in scripts folder. Notice that dotenv library is used to store secret keys or API keys in configuration file and the complete sample can be retrieved at .env file section.

Test setup

After installing all dependencies using npm install, all tests should be able to execute using npx hardhat test command that will:

• Compile contracts
• Generate artifacts
• Run all test scripts in test folder.

However, test can be run partially by passing in test script file path as argument to npx hardhat test in such a manner:

1. npx hardhat test test/MakeWorldPeace.js that will only execute tests in MakeWorldPeace.js
2. npx hardhat test test/MakeWorldPeaceV2.js that will only execute tests in MakeWorldPeaceV2.js
3. npx hardhat test test/MakeWorldPeaceV3.js that will only execute tests in MakeWorldPeaceV3.js

.env file sample

Create .env file in current path and refer to sample template below that should be inserted with corresponding API token and secret keys based on instructions above.

ALCHEMY_API_KEY=INSERT_YOUR_ALCHEMY_API_KEY_HERE
RINKEBY_PRIVATE_KEY="INSERT_YOUR_METAMASK_WALLET_RINKEBY_PRIVATE_KEY_HERE"
DEPLOYED_PROXY_ADDRESS="INSERT_PROXY_ADDRESS_THAT_SHOW_AFTER_FIRST_STEP_OF_DEPLOYMENT" 
GNOSIS_SAFE="INSERT_GNOSIS_SAFE_CONTRACT_ADDRESS_HERE"
DEFENDER_TEAM_API_KEY="INSERT_OPEN_ZEPPELIN_DEFENDER_TEAM_API_KEY_HERE"
DEFENDER_TEAM_API_SECRET_KEY="INSERT_OPEN_ZEPPELIN_DEFENDER_TEAM_SECRET_KEY_HERE"
ETHERSCAN_API_KEY="INSERT_ETHERSCAB_API_HERE"

Thing to take note

Change function upgradeToV2() public to function upgradeToV2() public onlyOwner in MakeWorldPeaceV2.sol

Deploy UUPS contract

In order to start deploying upgradeable ERC contract, script file is executed ascendingly as shown below. Make sure .env file is filled in accordingly except DEPLOYED_PROXY_ADDRESS as we will get the information after our first script.

1. Run npx hardhat run scripts/1_deploy.js --network rinkeby command in console and copy the deployed proxy address shown in output of the script into DEPLOYED_PROXY_ADDRESS. Check and make sure contract is already been created by searching deployed proxy address in Etherscan.
2. Run npx hardhat run scripts/2_transfer_ownership.js --network rinkeby command and ownership of the proxy address will be transferred from metamask wallet to Gnosis safe contract shown in output of the script.
3. Since we had transferred ownership to Gnosis Safe multi-sig contract, there is no straightforward way to update the contract using hardhat command. we could however generate upgrade proposal that can be further processed in OpenZeppelin Defender.
4. Log in into OpenZeppelin Defender and add proxy address contract into it. Fill in name (any name you like), network (Rinkeby), address(DEPLOYED_PROXY_ADDRESS). Notice that there is a space of ABI to be filled in.
5. In order to fill in the ABI accordingly, first the underlying implementation contract of proxy contract have to be verified and ABI is then retrieved from implementation contract in Etherscan. First, go to Etherscan then enter the verified implementation contract address. Next, click on the Contract in the tab section heading and scroll down to find the Contract ABI then copy it.
6. Paste into the ABI field in Step 5 and press Add to add proxy contract into OpenZeppelin Defender.
7. Run npx hardhat run scripts/3_propose_upgrade.js --network rinkeby command and click on the link shown in output of the script.
8. Approve proposal in OpenZeppelin Defender and proxy contract will be updated with new implementation contract. Keep note that each newly generated implementation contract have to be verified in order to obtain ABI and ABI should be updated in OpenZeppelin Defender proxy contract for contract interaction.
9. Create proposal to execute upgradeToV2() function in OpenZeppelin Defender and approve the proposal as this is the first function that should be executed after successfully upgraded the proxy contract.
10. Similar steps are taken to update contract to V3 by running npx hardhat run scripts/4_propose_upgrade_v3.js --network rinkeby command and click on the link shown in output of the script. Then,repeat step 8.

Verify contract

Go to proxy contract address in Etherscan and verify it as proxy contract. Copy the implementation contract address if it stated that implementation contract address is not verified yet.

Next, run npx hardhat verify <impl_address> --network rinkeby where <impl_address> is the implementation address copied above. Click on the link at the output of the command to verify contract is verified in Etherscan.

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Revision update

MakeWorldPeace ERC20 Token V3

Fix bug by adding role access modifier (BURNER_ROLE) to burn and burnFrom function of smart contract.

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MakeWorldPeace ERC20 Token V2

Change from owner access modifier to role-based access modifier. Each of the function have their own role such as:

• PAUSER_ROLE for all pause and unpause function
• MINTER_ROLE for mint function
• BURNER_ROLE for burn_supply function

Each of the role mentioned above can be granted and revoked by owner of address

Assigned role to the address can renounce their own role as well

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MakeWorldPeace ERC20 Token V1

Create ERC20 upgradeable contract with mint, pause (freeze) and burn function. Owner access modifier for following functions:

• pause and unpause
• mint
• burn_supply
• _authorizeUpgrade (for upgrading contract)

Maximum mint amounts of 10,000 within 3 minutes of block time in mint function