Lesson 8 : wait functionality of ethers usage

[aviorn36]

Hi Community,
In lesson 8, Patrick while creating front-end creates below function to listen whether the transaction has been mined or not.

function listenForTransactionMine(transactionResponse, provider) {
  console.log(`Mining ${transactionResponse.hash}`);
  return new Promise((resolve, reject) => {
    try {
      provider.once(transactionResponse.hash, (transactionReceipt) => {
        console.log(
          `Completed with ${transactionReceipt.confirmations} confirmations. `
        );
        resolve();
      });
    } catch (error) {
      reject(error);
    }
  });
}

We are also aware of wait(blockConfirmation number) functionality / method from ethers library, which kind of does the same thing (or is it?). Can some-one please let me know why should I go with the custom listenForTransactionMine and not wait()? Any differences or use-case?

I would really appreciate some help here :)

[krakxn]

@aviorn36

Context for provider.once:

Here, the event is the hash (which is only possible if the block containing the txn was indeed mined). Additionally, since this involves the usage of promises (and a try-catch for easier debugging), this one is more versatile than just using .wait() (which will just for the block containing the txn to be mined).

Put simply, this is a more modular approach and that you can definitely incorporate .wait() by yourself in a similar approach.