XDC Checkpoint Smart Contract

This repository contains scripts for building, testing, and deploying the XDC checkpoint smart contract. Follow the guide below to get started.

Prerequisites

Ensure you have Node.js version 20 or higher installed on your system.

Contract Building and Testing

Setting up the Environment

1. Install Dependencies Install the necessary dependencies using yarn:

   yarn

2. Testing Compile and test the contract using the following commands:

   npx hardhat test

Contract Setup

We recommend setting up the contract in a Python virtual environment since it utilizes the web3 library adapted for XDC. Before beginning, carry out these two steps:

1. Configuration

   Complete the fields in deployment.config.json:

   • subnet: subnet deploy config :
     • gap: GAP block number on the public chain
     • epoch: Blocks per epoch on the public chain
     • gsbn: gap start block number, gap block required
   • parentnet: Subnet deploy config :
     • epoch: Blocks per epoch on the public chain
     • v2esbn: V2 epoch start block number, epoch block required

   Configure your network in network.config.json:

   • xdcparentnet: xdcparentnet RPC URL
   • xdcsubnet: xdcsubnet RPC URL

2. Environment Variables

   Create a .env file containing a valid account private key (refer to .env.sample for an example).

How to Obtain gsbn in the Subnet

The gap block in the subnet follows a regular pattern. By adding 451 to each multiple of 900, you get the GSBN. For example, 451, 1351, etc.

How to Obtain v2esbn in the Parentnet

The epoch number in the parentnet is unpredictable, but you can obtain the latest epoch number using the following command:

curl --location '${parentnet}' \
--header 'Content-Type: application/json' \
--data '{
    "jsonrpc": "2.0",
    "method": "XDPoS_getMissedRoundsInEpochByBlockNum",
    "params": [],
    "id": 1
}'

Contract Deployment

Deploy the contract and obtain the deployed contract address as follows:

1. Full Checkpoint Deployment

   npx hardhat run scripts/FullCheckpointDeploy.js --network xdcparentnet

2. Lite Checkpoint Deployment

   npx hardhat run scripts/LiteCheckpointDeploy.js --network xdcparentnet

3. Reverse Full Checkpoint Deployment

   npx hardhat run scripts/ReverseFullCheckpointDeploy.js --network xdcsubnet

Additional Commands

For further assistance or to execute other operations, utilize the commands below:

npx hardhat accounts
npx hardhat compile
npx hardhat clean
npx hardhat test
npx hardhat node
npx hardhat help
REPORT_GAS=true npx hardhat test
npx prettier '**/*.{js,json,sol,md}' --check
npx prettier '**/*.{js,json,sol,md}' --write
npx solhint 'contracts/**/*.sol'
npx solhint 'contracts/**/*.sol' --fix

Gas Report

Refer to the gas report:

Upgrade Module

To upgrade the module, follow these steps:

1. Configuration

   Complete the fields in upgrade.config.json:

   • proxyGateway: The admin contract managing all proxy contracts.

2. ProxyGateway Deployment

   If you don't have a proxyGateway contract, deploy yours using:

   npx hardhat run scripts/proxy/ProxyGatewayDeploy.js --network xdcparentnet

3. Upgrading

   Upgrade the contract using:

   npx hardhat run scripts/proxy/UpgradeCSC.js --network xdcparentnet

Important reminder

Because the node might modify the value of certThreshold based on the configuration file, when the node makes such modifications, the certThreshold in the CSC needs to be hardcoded and upgraded accordingly.