Development Tutorial

Introduction

Joltify provides a simple hardhat project for Solidity smart contract deployment and interaction on Joltify EVM co-chain.

GitHub - carlthelegend/joltevmGitHub

The simple hardhat project

Step 1: Configuration setup

To access the Joltify local chain and Joltify Testnet chain, configure the corresponding networks in joltevm/hardhat.config.js as follows:

networks: {
    testnet: {
      url: "testnet_rpc_url",
      accounts: ["account_private_key"]
    }
  }

Alternatively, you can also set up accounts with seed phrases as follows:

networks: {
  testnet: {
      url: "testnet_rpc_url",
      accounts: {
        mnemonic: "test test test test test test test test test test test junk",
        path: "m/44'/118'/0'/0",
        initialIndex: 0,
        count: 20,
        passphrase: "",
      },
  }
}

Step 2: Contract deployment​

joltevm directory contains an integrated Hardhat project for smart contract deployment and interaction.

# Navigate to the joltevm directory
cd joltevm

# Install dependencies
yarn

A sample Solidity smart contract located at joltevm/contracts/token/Token.sol can be easily deployed with:

yarn token-deploy

Under the hood yarn token-deploy is running cmd npx hardhat run --network testnet scripts/deploy/token.js to deploy the token on Joltify testnet. You can also use the npx hardhat ... syntax to interact with the contracts from the CLI.

Step 3: Contract interaction​

Basic contract interaction is possible through additional scripts with the full list available in evm/package.json. Each yarn cmd is aliased to one of the Hardhat tasks found in hardhat.config.js.

# Get the deployed TEST token's total supply
yarn token-totalSupply --token TOKEN_CONTRACT_ADDRESS

You can get information about any cmd including param options by using the --help flag, for example:

yarn token-totalSupply --help

Using the available scripts, we can transfer tokens:

yarn token-transfer --token TOKEN_CONTRACT_ADDRESS --recipient RECIPIENT_ADDRESS --amount AMOUNT

Step 4: Customised contract deployment​

You can easily deploy your own contracts:

1. Add your Solidity smart contract to joltevm/contracts.

2. Add a deployment script to joltevm/scripts/deploy/[YOUR_SCRIPT].js.

3. Add Hardhat tasks corresponding to your contract's public methods to the existing tasks in hardhat.config.js.

Done! Now you can deploy and interact with your contract:

# Deployment on Joltify testnet
npx hardhat run --network testnet scripts/deploy/[YOUR_SCRIPT].js

# Interaction on Joltify testnet
npx hardhat [YOUR_TASK_NAME] --network testnet

If you want a cleaner CLI experience, you can add some script aliases to joltevm/package.json as seen in the scripts section.

Step 5: Contract verification

To verify the deployed contract on joltify EVM explorer, you are required to set up etherscan in hardhat.config.js file as follows:

etherscan: {
    apiKey: {
      testnet: "any_but_not_empty",
    },
    customChains: [
      {
        network: "testnet",
        chainId: 1730,
        urls: {
          apiURL: "https://backend-evm-dev.joltify.io/api/",
          browserURL: "https://evm-explorer-dev.joltify.io/"
        }
      }
    ]
  }

Once the configuration is set up, you can run the following command to verify the deployed contract on Joltify EVM explorer:

npx hardhat verify --network testnet --contract contracts/token/Token.sol:Token DEPLOYED_CONTRACT_ADDRESS "constructor argument 1"

or

yarn verify --contract contracts/token/Token.sol:Token DEPLOYED_CONTRACT_ADDRESS "constructor argument 1"