When to wait for block confirmations

[amineprogmine]

Hello,

Scratching my head... I am still confused and some things are not clear to me after watching the tutorial:

1/ when do we have to wait for block confirmations and why:

describe("Mint NFT", () => {
              beforeEach(async () => {
                  const txResponse = await basicNft.mintNft()
                  await txResponse.wait(1)
              })

I usually just go straight to what I need from the contract, and it doesn't work.

2/ where this is coming from:

await deployments.fixture(["basicnft"])

why do this and what is does? fixture, where is that coming from

          beforeEach(async () => {
              accounts = await ethers.getSigners()
              deployer = accounts[0]
              await deployments.fixture(["basicnft"])
              basicNft = await ethers.getContract("BasicNft")
          })

[Koowah]

Hi @amineprogmine ,

Using wait on a tx response returns a tx receipt. You can see the difference between the response and the receipt in the ethers documentation or in the ethers.js part of Patrick's course.

Practically, in a live network, using wait(1) assures you that your transaction has been mined.

The deployments object comes from the hardhat-deploy plugin. The fixture method allows you to deploy a contract using the deploy script that has the specified tag : basicnft in your case.

Cheers 😄

[alymurtazamemon]

@amineprogmine

1. When you perform any kind of WRITE transaction you should wait for block confirmations, for READ is not required. Why is it required? Because WRITE changes the state of the blockchain and creates transactions so we wait for the confirmation that whether our transaction gets confirmed or not.
2. fixture is just a function provided by the hardhat-deploy plugin which deploys contracts before starting tests. It takes a list of tags contained inside the deploy scripts. In order to use contracts in our test we need to deploy them.

[moayuisuda]

but why in some test.js code the .wait(1) is not necessary?
just like https://github.com/PatrickAlphaC/hardhat-fund-me-fcc/blob/main/test/unit/FundMe.test.js#L41

  it("Updates the amount funded data structure", async () => {
      await fundMe.fund({ value: sendValue })
      const response = await fundMe.getAddressToAmountFunded(
          deployer
      )
      assert.equal(response.toString(), sendValue.toString())
  })

[Koowah]

@moayuisuda
If I'm not mistaken, it is due to the fact that the hardhat network is used in that example.

In that setting, any transaction automatically mines a block, so there's no need to .wait(1) for the transaction to be mined like you would in an actual network.

[moayuisuda]

@Koowah thanks! Does this auto mine behavior only occers in hardhat network? if i'm working on a local ganache network, will auto mine happen?

[Koowah]

@moayuisuda Also works on ganache