Mail::Message#to does not always return the same type of object

[kjg]

Ultimately Mail::Message#to delegates to calling #default on the field object of the To: header.

If the To header's field is a Mail::ToField, Mail::Message#to returns a Mail::AddressList due to the way default is defined in Mail::CommonAddress

However, if for some reason the To field encountered an error in parsing the hear's field is now an Mail::UnstructuredField which returns a string of the decoded value when calling default

I run into issues when I assume Mail::Message#to is going to return an enumerable Mail::AddressList, but instead get a string. Any thoughts on what we might be able to change to make this behaviour more expected?

I understand the simplicity of having a default method on each field and why the header's field is an Unstructured field when the content is not parseable.

Would it make sense to add extra logic in Mail::Message#to to check the return value of #default and wrap it in a enumerable or something if it is not an AddressList? Or any other suggestions?

Thanks