This doc isn’t very helpful: Action Mailer Basics — Ruby on Rails Guides
Getting Started with Rails — Ruby on Rails Guides mention the word “helper” a few times but never defines what a helper is or how you should work with one.
If you google
rails mail view helpers (I wanted to use a method that’s defined in a view helper in a mailer view) there’s a lot of answers that don’t seem to work very well.
I eventually stumbled on Deletes the private method add_template_helper · rails/rails@cb3b37b · GitHub which breaks the top answer here, and based on that figured out that you should use
helpers ModuleName, which is not a pattern I’d seen before.
I am happy to write docs but would love confirmation that I’m doing it right.