Cronos Hardhat Boilerplate

Hardhat dependencies (including typescript dependencies) included in this repo

This project was created with npx hardhat init (see hardhat.org), using Typescript.

It leverages the following libraries:

• OpenZeppelin contracts (https://docs.openzeppelin.com/contracts/)

Set-up

npm install

See the configuration file hardhat.config.ts including network details for Cronos blockchain.

Create .env file for environment variables, using .env.example as template.

Create your contract(s)

Smart contracts are created in the /contracts directory.

You can use https://wizard.openzeppelin.com/ to generate standard code.

Local deployment and testing

Compile the smart contracts:

npx hardhat compile

Execute the test script, and then calculate the test coverage of the smart contract code:

npx hardhat test
npx hardhat coverage

The test also incluces a gas report when the .env file includes: REPORT_GAS=true npx hardhat test.

Deploy the smart contract to the local blockchain network:

npx hardhat run scripts/DeployMyERC20.script.ts --network hardhat

Deployment to Cronos

Cronos Tesnet:

npx hardhat run scripts/DeployMyERC20.script.ts --network cronosTestnet

Cronos Mainnet:

npx hardhat run scripts/DeployMyERC20.script.ts --network cronos

Don't forget to note the address of the contract after deployment.

Contract verification on the block explorer

For contract verification, you need an API key for the Explorer API. Here are the URLs where you can register in order to request an API key:

• Cronos Mainnet: https://explorer-api-doc.cronos.org/mainnet/
• Cronos Testnet: https://explorer-api-doc.cronos.org/testnet/

Contract verification requires custom chain configuration in hardhat.config.ts. See the hardhat.config.ts file in this repository for Cronos testnet and mainnet configurations.

To see the list of supported blockchain network for contract verification:

npx hardhat verify --list-networks

Verify on Cronos Testnet by including the constructor's arguments in the command line:

npx hardhat verify --network cronosTestnet "DEPLOYED_CONTRACT_ADDRESS" "My token name" "My token symbol"

Of, if the constructor's arguments have been saved in the "./scripts/deploy-verification-arguments.js" file:

npx hardhat verify --network cronosTestnet "0x3F273114f20f87C602D87E1f1cd87D6F3ae5Ac72" --constructor-args "./scripts/deploy-verification-arguments.js"

Verify on Cronos Mainnet:

npx hardhat verify --network cronos "DEPLOYED_CONTRACT_ADDRESS" "Constructor argument 1" "Constructor argument 2"

Deployment and verification on Ethereum Sepolia testnet

npx hardhat run scripts/DeployMyERC20.script.ts --network ethereumSepoliaTestnet
npx hardhat verify --network ethereumSepoliaTestnet "DEPLOYED_CONTRACT_ADDRESS" "My token name" "My token symbol"