Interact with deployed Smart Contracts using NodeJs and Ethers.js

In our previous post, we covered how to develop and deploy the smart contract using Ethers.js

here I explained how to interact with the deployed contract.

1. Using a contract instance, we can use the contract method. Here's the deployed contract.

pragma solidity ^0.8.0;

contract SimpleStorage {
    uint256 public data;

    function set(uint256 _data) public {
        data = _data;
    }

    function get() public view returns (uint256) {
        return data;
    }
}        

2. Required config - contractAddress

 const contractAddress = "0x85E7058484R725789b7873c2563F864C12AAf9BB"; 
//Replace with your contract address        

3. Connect the provider and wallet.

4. Create the interact.js file in the project directory.

const { ethers } = require("ethers");
const fs = require("fs");
require("dotenv").config();

// Configuration 
const contractAddress = "0x85D7058484C725789b7873c2563F864C12AAf9BB"; // Replace with your contract address

async function interactWithContract() {
  const contractJson = JSON.parse(fs.readFileSync("simple.json"));
  const abi = contractJson.abi;
  const bytecode = contractJson.bytecode;
  const provider = new ethers.JsonRpcProvider(process.env.PROVIDER_URL);

  const wallet = new ethers.Wallet(process.env.PRIVATE_KEY, provider);

  const contract = new ethers.Contract(contractAddress, abi, wallet);

  const currentData = await contract.get();
  console.log("Current stored data:", currentData.toString());

  //Set data
  const newData = 154;
  console.log(`Updating data to: ${newData}...`);
  const tx = await contract.set(newData);
  await tx.wait();
  console.log("Transaction confirmed!");

  //   Get the updated stored value
  const updatedData = await contract.get();
  console.log("Updated stored data:", updatedData.toString());
}

interactWithContract().catch(console.error);
        

5. Create the contract instance with the address, abi, and wallet.

6. By using instance, we can call the contract methods.