How to List<> of exceptions from ArgumentException and throw a AggregateException

Question

private void AccountValidations(CreateAccountPayload payload) {
  if (string.IsNullOrEmpty(payload.Note)) {
    throw new ArgumentException($ "Note cannot be empty");
  }
  if (string.IsNullOrEmpty(payload.AccountName)) {
    throw new ArgumentException($ "Account Name cnnot be Empty");
  }
  if (string.IsNullOrEmpty(payload.Type)) {
    throw new ArgumentException($ "Account Type cnnot be Empty");
  }
}

I want all the exception messages at once, eg: In the payload object if I don't provide AccountName and Note . It should report me both Note cannot be empty and Account Name can not be Empty How can I do that?

I thought of making a List of all these messages and then throw a Agregateexception . How can I do this?

Answer 1

Well, to validate your CreateAccountPayload you can do the following.

A. You can indeed throw the AggregateException but first you need to add your exceptions to the list.

var exceptions = new List<Exception>();
if (string.IsNullOrEmpty(payload.Note)) {
exceptions.Add(new ArgumentException($ "Note cannot be empty"));
}
 if (string.IsNullOrEmpty(payload.AccountName)) {
exceptions.Add(new ArgumentException($ "Account Name cnnot be Empty"));
}
if (string.IsNullOrEmpty(payload.Type)) {
exceptions.Add(new ArgumentException($ "Account Type cnnot be Empty"));
}
if (exceptions.Any()) throw new AggregateException(
    "Encountered errors while validating.",
    exceptions);

The outer code should catch the exception.

catch (AggregateException e)

You just need to inspect the InnerExceptions property and construct the errors string like this

string.Join(" and ", e.InnerExceptions.Select(ex => ex.Message));

B. Another option might be the following. You can add your messages (not throwing exceptions) to a List of strings, and return it. And if the list is empty - validation passed.