Lesson 7: Hardhat Fund Me : explain namedAccounts

[kloudplanet]

I'm struggling to understand how to use namedAccounts with different chain.

let's say I've this namedAccounts configuration in hardhat.config.js

namedAccounts: {
    deployer: {
      default: 0, 
      1: 0, 
      4: 0,
    },
    feeCollector: {
      default: 1, 
      1: "0xa5610E1f289DbDe94F3428A9df22E8B518f65751", 
      4: "0xa250ac77360d4e837a13628bC828a2aDf7BabfB3", 
    },
  },

what I understand is now I've 2 accounts (deployer, feeCollector) when I use code await getNamedAccounts().

but I'm struggling to understand this options and how hardhat-deploy will use this namedAccounts?

first of all what is the meaning of default? when hardhat-deploy will use default? will it be used by all the chainId or by only local chain?

other object keys are chainID like 1 (mainnet), 4 (rinkeby) but what's it's value and how it will be used by hardhat-deploy?

not able to understand 1:0, 4:0, 1: "0xa5610E1f289DbDe94F3428A9df22E8B518f65751", 4: "0xa250ac77360d4e837a13628bC828a2aDf7BabfB3",

Thanks.

[dibakarsutradhar]

• How hardhat-deploy will use this namedAccounts?

getNamedAccounts() is a part of the Hardhat Runtime Environment or in short hre, which makes every configuration you write in the hardhat.config file globally available throughout that particular Hardhat project. So whenever you call the getNamedAccounts() in any of your deploy or test scripts, that specific namedAccounts object and all of its children's become available to that script, and you would be then assigning the deploy script to your desired account. Such as an example -

await deploy('MockV3Aggregator', {
      contract: 'MockV3Aggregator',
      from: deployer,
    });

Here, in the from section, I've passed the deployer account, but with your config object, the feeCollector should also be available to deploy the contract. And that should look something like this -

await deploy('MockV3Aggregator', {
      contract: 'MockV3Aggregator',
      from: feeCollector,
    });

• Hardhat Default

When you initiate a hardhat project, the compiler gives you access to an HD-Wallet consisting 20 mock accounts. By default, the default localhost/hardhat account that would be used as a deployer is the 0. Now the 0 here is not the zero number or an account address, the 0 here is simply referring to the first indexed account of the wallet. All the addresses in a wallet are stored in an array, so the 0 here is the first item of that array. For a hardhat project this 0 should refer to 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 this specific address. More about Hardhat Runtime Environment & Network

This format and config file is available to the local chain, testnet and mainnet. If you deploy this contract to Ethereum Mainnet or any other testnet, the default account 0 indexes would be referring to the first account of your MetaMask Wallet.

• FeeCollector Object Keys and Specific Address Referring

In your feeCollector, you have specifically mentioned which account and addresses to use for that specific function. Hence whenever you will call this feeCollector account, on a local network, hardhat will use the 1 index account or the 2nd item of the array from its local wallet, which should be 0x70997970C51812dc3A010C7d01b50e0d17dc79C8 address. Now when you deploy the contract to testnet (4: rinkeby in your case), the testnet will specifically and strictly use the 0xa250ac77360d4e837a13628bC828a2aDf7BabfB3 address for the transaction and when you deploy the contract to mainnet (1: Ethereum), the mainnet will specifically and strictly use the 0xa5610E1f289DbDe94F3428A9df22E8B518f65751 address for the transaction related to feeCollector account.

Hope I was able to clarify & help.