Openzeppelin upgradeable smart-contract example

Deploy upgradeable smart contract using Openzeppelin on local test network OR polygon test network. This example uses Transparent Proxy approach for deploying upgradeable smart contract.

Commands to create a new project using Hardhat

1. mkdir openzeppelin_upgradeable_sc

2. cd openzeppelin_upgradeable_sc

3. npm init --yes

4. npm install --save-dev hardhat

5. npx hardhat

6. Create an .env file by renaming env.example to .env and add the private-key and rpc api-key in this file. we require these keys for configuring hardhat.config.js file. please note that private-key and rpc api-key is only needed when using polygon_test network.

7. Please add this .env file to .gitignore to avoid putting private information to github.

8. Install npm i dotenv package to use the environment variables from .env file.

9. We can add more plugins like hardhat-gas-reporter, solidity-coverage and hardhat-solhint using below commands.

   A. npm install hardhat-gas-reporter --save-dev. For more info please refer documentation

   B. npm install solidity-coverage --save-dev. For more info please refer documentation

   C. npm install @nomiclabs/hardhat-solhint --save-dev. For more info please refer documentation.

10. Since we are using openzeppelin then we have to add some plugins.

    A. npm install @openzeppelin/contracts

    B. npm install --save-dev @openzeppelin/hardhat-upgrades

    C. hardhat-config.js is already configured to use the hardhat-upgrade plugin.

Compile Project

npx hardhat compile

Test Project

npx hardhat test

Deploy Project

WARNING: There is some issue with Polygon rpc testnet endpoints. They are not responding well when deploying the upgradeable smart-contract.

1. Open a new terminal and start a hardhat local node using command npx hardhat node.

2. Deploying deployProxy script using command npx hardhat run --network localhost scripts/deployProxy_box.js. please note down the address.

3. Lets test the above smart-contract but first lets update the contract address here in execute_boxv1_func.js script. Now let's deploy the script using command npx hardhat run scripts/execute_boxv1_func.js --network localhost. It will return 13 as a value.

4. Now it's time to deploy BoxV2 smart-contract which contains additional functionality when compared to Box smart-contract.

5. We will be using upgradeProxy script for this operation. But before deploying this script, please make sure to replace the address here with the contract address generated in Step 2.

6. Deploy the script using command npx hardhat run --network localhost scripts/upgradeProxy_box.js

7. Now we have successfully upgraded the smart-contract Box to Boxv2 while keeping its state and the same contract address as before. Compare the output of Step 2 and Step 5. Both are using same contract address.

8. Now lets test the BoxV2 smart-contract by deploying the execute_boxv2_func.js script. But before deploying it, update the contract address here. Now lets deploy the script using command npx hardhat run scripts/execute_boxv2_func.js --network localhost. It will return 35 as a value.

References:

Hardhat docs

OpenZeppelin docs v4.x

Youtube Video: OpenZeppelin Upgrade contracts

Credits

OpenZeppelin Team