The from_address method is added to Mail::Message, but is not used
internally to ActionMailbox, nor tested (even implicitly). As it is part
of the public API, it feels important to at least have a basic test of
it.
Similarly, the x_original_to_addresses was only implicitly tested via
the recipients_addresses method. Given other similar methods are
explicitly tested, it feels like an oversight not to test it as well.
As the test introduced from_address didn't align with the naming of
RecipientsTest, I renamed it to the more generic AddressesTest.
Allow passing a block to the create_inbound_email_from_mail and
receive_inbound_email_from_mail test helper methods.
When you wanted to test a multipart email -- for example, an email that
has both a plaintext part and an HTML part -- there wasn't a way to
easily build one without a pre-made fixture. By allowing you to pass a
block to these methods, we unlock the power of Mail.new to easily
create a variety of emails, from multi-part emails, to emails with
attachments, and beyond.
Currently, the only exposed entry point into the ApplicationMailbox's configured
routing system is to call `route`, which performs a lot of work to fully
`process` inbound email. It'd be nice to have a way (e.g. in test) of checking
which mailbox an email would route to without necessarily processing it yet.
This also adds a new column, message_checksum, to the action_mailbox_inbound_emails table
for storing SHA1 digest of the email source. Additionally, it makes generating the missing
message id deterministic and adds a unique index on message_checksum and message_id to
detect duplicate emails.
