How to call a function after an asynchronous for-loop?

Question

I have the following for-loop :

for await (const account of accountCursor) {
  const newAccount = handleAccount(account, migrationService);
  try {
    await migrationService.accountService.create(newAccount);
  } catch (error) {
    console.log('Unable to create account');
    throw Error(error)
  }
}

handleRelatedAccounts();  // call once the for-loop has completed

Once it has finished, I want to call another function. Since it is asynchronous, how can I call the function after the for-loop has finished, not during?

Answer 1

Assuming you want to run the function whether or not an error is caught and re-thrown in your loop, you can just wrap the entire loop in a try...finally statement: below is an example. (If not, I'm not sure why you are re-throwing the caught error and what kind of behavior you expect.)

try {
  for await (const account of accountCursor) {
    const newAccount = handleAccount(account, migrationService);
    try {
      await migrationService.accountService.create(newAccount);
    } catch (error) {
      console.log('Unable to create account');
      throw Error(error)
    }
  }
}
finally {
  handleRelatedAccounts();  // call once the for-loop has completed
}

Answer 2

You do not have to do anything. handleRelatedAccounts(); always run after the loop. await means it will wait until the premise is finished to do the next code. Because you throw Error(error) , it will stop the execution when there is an exception, handleRelatedAccounts(); will be never hit in this case.