Cross Chain Tutorial L2 Counter Part 1

L2 Counter

Now that we have an address for the L1 governance contract, we can build, deploy, and test the counter contract on L2.

1. cd out of L1-governance and initialize the L2-counter project:

   npx zksync-cli create L2-counter --template hardhat_solidity
   

2. Use the same private key for the WALLET_PRIVATE_KEY variable in the .env file.
3. For the purposes of this tutorial, we don't need the example smart contracts and deployment script files generated by zksync-cli. Run the following commands to remove them:

   cd L2-counter
   rm -rf ./contracts/*
   rm -rf ./scripts/*
   

Create L2 Counter Contract

1. In the L2-counter/contracts/ directory, create a new file Counter.sol.

   touch contracts/Counter.sol
   

   
   This contract contains the address of the governance contract deployed previously on layer 1, and an incrementable counter which can only be invoked by the governance contract.
2. Copy/paste the following code into the file:
   Counter.sol

   // SPDX-License-Identifier: Unlicense
   
   pragma solidity ^0.8.17;
   
   contract Counter {
     uint256 public value = 0;
     address public governance;
   
     constructor(address newGovernance) {
       governance = newGovernance;
     }
   
     function increment() public {
       require(msg.sender == governance, 'Only governance is allowed');
   
       value += 1;
     }
   }
   

3. Compile the contract from the L2-counter root:
   Compilations happens only after the installation of a compiler.
   npmyarnpnpmbun

   npm run compile