lesson- 9 localhost deploy error

[TimeKeyRoll]

red color When i try to run npx hardhat node it says already in use. What does that mean and how to fix it?

yellow color when i try to run npx hardhat deploy --network local host it gets deployed.

green color when i run npx hardhat node its gets re-deployed and gives us different account.

so yellow and green both accounts are different. how did that just happen?

[RoboCrypter]

@MasterofBlockchain : Is your hardhat node running in your other terminals as well ?

[TimeKeyRoll]

Well let me explain the issue here! first i ran npx hardhat node to run node and it gets deployed with an address and shows number of accounts as in the screenshot.

As per the deployed address i check in node addresse and could not find.

Then i run npx hardhat deploy --network localhost and it also get deployed and showed a different address. and that address is also not in node addresses.

so the questions are why there are two different addresses? and how come while running node an address is getting genrated?
And both of the generated addresses does not match with node addresses.....

[RoboCrypter]

@MasterofBlockchain : Those are your contract addresses not wallet addresses so they will not be present in your hardhat node.

[TimeKeyRoll]

Probably I failed to ask the question in right way.
Let me rephrase- when I run 'node' then automatically contract gets deployed. Why!? Is that normal!?

And when I run 'npx hardhat deploy - network local host'.. Contract gets deployed as well
But this contract address is different than the address which I got while running 'node'..

So I have two addresse one come from 'node' and other 'localhost'...

How these two addresses are connected!? And how come i have two addresses? @othaime-en

[othaime-en]

Hey @MasterofBlockchain you are getting this error because there is another service/process using the port 8545. In simple terms, you have another terminal that is already running yarn hardhat node use that terminal or kill it before you open a new one

[TimeKeyRoll]

Great ~ When running your contracts and tests on Hardhat Network you can print logging messages and contract variables calling console.log() from your Solidity code. To use it you have to import hardhat/console.sol in your contract code.

Mentioned above line is from docs.

-->the one you have mentioned does not need to get import and console.log thing could be done directly in terminal.

--> the one i read from docs is need to import in contracts and console.log needs to be written within the contract and out of console.log will be shown in terminal.
https://hardhat.org/tutorial/debugging-with-hardhat-network

so What's the difference between these two terminals?

[othaime-en]

There is a difference. The console.log() in my example above is javascript based (since the hardhat console is a javascript environment) while the console.log() you are talking about is for solidity. and it is written directly inside you FundMe or Lottery contracts. For example, if you wanted to log out / print out somethings inside your contract (e.g. console.log("User Entered") whenever a user joined the lottery) you could use console.log() but you will have to import it with import hardhat/console.sol; inside your contract same as you did with VRFConsumerBaseV2, KeeperCompatibleInterface or any other functionality you imported in your contracts.
The main difference here is that one works on the javascript environment while the other works on the solidity environment.

[TimeKeyRoll]

There is a difference. The console.log() in my example above is javascript based (since the hardhat console is a javascript environment) while the console.log() you are talking about is for solidity. and it is written directly inside you FundMe or Lottery contracts. For example, if you wanted to log out / print out somethings inside your contract (e.g. console.log("User Entered") whenever a user joined the lottery) you could use console.log() but you will have to import it with import hardhat/console.sol; inside your contract same as you did with VRFConsumerBaseV2, KeeperCompatibleInterface or any other functionality you imported in your contracts. The main difference here is that one works on the javascript environment while the other works on the solidity environment.

so the one which you have mentioned works on javascript environment and could be used to get console.log value direct in our terminal. And it works only on contracts.

whereas solidity console.log can work on contracts and tests and console.log needs to be written within the contract and tests...

And how do we know if we want to use solidity console or java script console? :/ lol

[othaime-en]

Ok javascript console (The one I mentioned) is just the same thing as the console.log we write in our deploy scripts or tests. While solidity console.log (The one we import through import hardhat/console.sol) works inside contracts/solidity files only. A difference I would like to point out here is that javascripts console interacts with the contracts while solidity console is written inside the contract. So regarding when to use one or the other, we use javascript console when we are interacting with contracts like we do in deploy scripts or tests while we use solidity console when writing solidity code/ contracts.

[TimeKeyRoll]

Such a great teacher! Appreciate and loving the learning from you ser.
thankyou.

[krakxn]

As for the discrepancy between the accounts: it is so because everytime you use the node command, it essentially starts up a completely new (i.e. fresh) blockchain from scratch. Hence, the difference is seen.

As for the error, it is so because of the same port being hosted somewhere else. Put simply, there is a terminal or some application which is hosting some sort of a HTTP-server (similar to the VSCode extension); which results in a collision as it is already in use.

This can be resolved by either using a different port altogether, or eliminating the process hosting on the port you are hosting on.

[TimeKeyRoll]

Thanks man. Can we go slow and so I could understand each things clearly and it keeps my doubts away!? BUT I appreciate you trying to explain in your way.

----- what happens when we run 'npx hardhat deploy' or 'npx hardhat deploy network - - localhost'!?

Where our contracts are getting deployed in both cases!? And how they are different from each other!?

Can you please explain me this!?

[krakxn]

In summary, put simply there is no difference between deploying on Hardhat and Localhost. The functionality is the same.

Both of them deploy on a test environment hosted on your computer.

[TimeKeyRoll]

If there is no difference then why they are there!? There is a difference on development level. I have understood how they work and what's the purpose behind them. @othaime-en has beautifully explained right down below.

But thanks @krakxn for your explanation as well but @othaime-en has clear all the doubts in my head while giving me the explanation in layman language.
Appreciate both of you.

[krakxn]

Precisely, the "why" is very subtle. It is to account for, that @othaime-en outlined, the discrepancies between the process finishing and not finishing (and that we have to kill the process manually).

So, in accordance with what our purpose is, we use the two; but it is important to note that the general functionality remains the same for them, with the sole difference being our purpose.

[TimeKeyRoll]

OK thanks :)

[TimeKeyRoll]

@othaime-en I think there is a confusion here.

let me rephrase what i have understood.

---When we run npx hardhat deploy it's actually deploying on hardhat network and gives us automated contract addresses... is that right?

---And when we run npx hardhat deploy --network localhost it is still getting deployed on hardhat network and gives us automated contract addresses...

So how these above two are different from each other? What's the difference between deploying on npx hardhat deploy or npx hardhat deploy --network localhost?

---And when we run node we see a couple of accounts and privatekey and when do we use/how do we use those addresses locally?

I am sorry there is confusion going on.

[othaime-en]

Before I answer, I'd like to remind you that hardhat gives us two network options for us to deploy to. 1. hardhat network 2. localhost. If you check your hardhat.config.js or helper-hardhat-config.js file we normally have these two. The hardhat network works at runtime and terminates once the script finishes running while the localhost (npx hardhat node or npx hardhat deploy --network localhost) is persistent and stays until we kill it off.

1. Yes. when we run npx hardhat deploy we deploy to the hardhat network because the default network is hardhat. We get automatic contract address for our contract too.
2. No. when we run npx hardhat deploy --network localhost we deploy to the localhost provided we initially started the network with npx hardhat node. We also get an automatic contract address
3. The difference between these two is what I started with above. About the difference when it comes to deploying, there isn't much difference, in most cases, the contract is deployed to the same address (both on hardhat and localhost) either way, you can still interact with it. One thing to note though is that if you deployed to localhost and you killed the node, you'll have to restart the node again to get the deployment.
4. Remember how in the beggining of the course how when we started using hardhat we were told that there is no need to include an accounts in the hardhat or localhost network sections in our hardhat.config.js files because hardhat does that for us automatically? Well this list of accounts we normally use it in our namedAccounts section by mostly assigning it to the deployer. If you have set deployer to 0 or 1 or 2 the respective account at that index in this list will be used. So for example in your case, using the first screenshot, if deployer was set to 0 we will use Account #0: 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 and if deployer was set to 1 we would have used Account #1: 0x70997970C51812dc3A010C7d01b50e0d17dc79C8 (10000 ETH). The private key of course you know we use it as kind of the username and password to allow us to perform transactions from whatever account we chose.

I hope this clears your doubt.

[TimeKeyRoll]

Oh MAN! This has clearly tells me what i was lacking to understand. Appreciate man.