About 00-deploy vs 01-deploy

[TimeKeyRoll]

I understand in deploy folder we have 00-deploy-mocks.js and 01-deploy-fundme.js.
and first is for local testing and second one is for testnet.

however in 01-deploy-fundme.js we have this ----

  let ethUsdPriceFeedAddress
    if (develompentChains.includes(network.name)) {
        const ethUsdAggregator = await deployments.get("MockV3Aggregator")
        ethUsdPriceFeedAddress = ethUsdAggregator.address
    } else {
        ethUsdPriceFeedAddress = networkconfig[chainId]["ethUsdPriceFeed"]
    }

And what is confusing me is why if and else statement in here. it simply says if this happens go for locally and if that happens go for testnet.. why we have mentioned about local here if we have 00-deploy-mock.js for that.
does that mean we have merged the 00-deploy-mock.js with 01-deploy-fundme,js account? if yes then can we delete -00-deployfile? if no then why did we mentioned aboutlocal` twice in both codes...

can anyone help me to understand this in easy terms please?

[othaime-en]

Hey @MasterofBlockchain to be clear, 00-deploy is not for deploying our contract locally, it is for deploying mocks locally. We also use 01-deploy to deploy locally our contract. What the if statement above effectively says, is that if we are on a local chain, we want to deploy the mocks - as so we use 00-deploy to deploy these mocks. but if we are on a testnet, we use the address ethUsdAddress that we put in our helper-hardhat file as the address for the priceFeed

[TimeKeyRoll]

Wonderful! So '00-deploy' is to deploy mocks... And '01-deploy' is for contract deployment either locally or test net?

[othaime-en]

Exactly. Excellent summary!
01-deploy is what we use to deploy the contract either locally or on a testnet. So we use the if statement above to make sure that whatever chain we deploy to (locally or on a testnet) we have an address for the pricefeed. And so if we are on a local chain we take the address of the mock contract deployed by 00-deploy and if we deployed on a testnet, we take the address we put in the helper-hardhat-config file.

[krakxn]

^

In addition, both the Mock and FundMe are contracts. The role of the deploy scripts is to deploy these contracts as per the code.

And as the code makes a difference b/w the two in terms of where they are deployed, it follows that when we run it, we deploy the Mock contract locally (i.e. developmentChains) and the FundMe contract either testnet/mainnet or locally.

[othaime-en]

Yes. Thanks @krakxn for that elaboration

[TimeKeyRoll]

Sure got it. Thanks @krakxn

[krakxn]

Put simply,

If we are on a local network:

We use the MockV3Contract contract's address for ethUsdPriceFeedAddress

Whereas, if we are not on a local network (i.e. testnets, mainnets):

In this case, we use the ethUsdPriceFeed's address (provided in networkConfig) for ethUsdPriceFeedAddress

Why the difference? Because in the latter, ethUsdPriceFeed is via the Chainlink datafeed (which is a contract deployed on mainnet). And as Patrick explains in the video, we use a Mock for local development.

[TimeKeyRoll]

Thank you :)