How to deploy contract with ether.js

Question

I am trying to figure out the best way to deploy a contract using ethers.js

with web3 I can just do:

     const contractInstance = new this.web3.eth.Contract(contractObject.abi)
        var deployTx
        debug(contractInstance)
        if (params === undefined || params.length === 0) {
          deployTx = contractInstance.deploy({
            data: contractObject.bytecode
          })
        } else {
          deployTx = contractInstance.deploy({
            data: contractObject.bytecode,
            arguments: params
          })
        }
        const data = await deployTx.encodeABI()

However with Web 3 I also seem to need an address? and to get that address I have to first manually deploy it. Some clarity around the topic would really help.

I've tried to find resources specifying this but they are not what what im looking for I think?

Thanks in advance

Answer 1

You can deploy a contract using Ethers.js' ContractFactory.

import { ContractFactory } from 'ethers';

const factory = new ContractFactory(contractAbi, contractByteCode);

// If your contract requires constructor args, you can specify them here
const contract = await factory.deploy(deployArgs);

console.log(contract.address);
console.log(contract.deployTransaction);

More information can be found in the documentation, found here: https://docs.ethers.io/v5/api/contract/contract-factory/

Answer 2

To further elaborate Marten's answer, I will try to give a complete script. Assuming you have installed metamask, and know the seed phrase, here are steps to deploy contract using 'ethers' and 'fs':

1. compile the contract to .bin and .abi files
2. load 'ethers' and 'fs'
3. create a 'signer' object using 'provider', 'Wallet', and 'connect' methods from 'ethers'
4. create a contract instance from 'ContractFactory' method
5. use deploy method as promise

Here I have used 'getblock' as web3 provider for example (see https://getblock.io/docs/get-started/auth-with-api-key/). Other alternatives are 'quicknode', 'alchemy' and 'infura'.

nodejs script for contract deployment goes here:

//load 'ethers' and 'fs'
const ethers = require('ethers');
const fs = require('fs');
    
//Read bin and abi file to object; names of the solcjs-generated files renamed
bytecode = fs.readFileSync('storage.bin').toString();
abi = JSON.parse(fs.readFileSync('storage.abi').toString());
  
//to create 'signer' object;here 'account'
const mnemonic = "<see-phrase>" // seed phrase for your Metamask account
const provider = new ethers.providers.WebSocketProvider("wss://bsc.getblock.io/testnet/?api_key=<your-api-key>");
const wallet = ethers.Wallet.fromMnemonic(mnemonic);
const account = wallet.connect(provider);
  
const myContract = new ethers.ContractFactory(abi, bytecode, account);
  
//Ussing async-await for deploy method
async function main() {
  // If your contract requires constructor args, you can specify them here
  const contract = await myContract.deploy();
  
  console.log(contract.address);
  console.log(contract.deployTransaction);
}
    
main();

In the above code 'account' is the of the ethers docs https://docs.ethers.io/v5/api/contract/contract-factory/#ContractFactory--creating

ethers.ContractFactory( interface , bytecode [ , signer ] )

Please ask if still having problem.