Allow from address to fall back to parent mailer

[djfpaagman]

I'm in a situation where I want the parent mailer class to set the from address.

The use case is that based on the I18n.locale we set a different from address/domain.

Right now it's not possible to do this, as even with nil for default_from_address it will not fall back to the parent (the mailer will fail: ArgumentError (SMTP From address may not be blank)). That basically means only one, fixed from address is supported.

I've come up with a small PR that makes that work by not setting the default value if it's nil.

Curious to hear what you think, I'm not entirely sure about:

• Is the config the right place for that mailer_defaults method? Feel like it could also live in the Passwordless::Mailer class.
• Does it even need it's own method like this, since there's only one default being set right now. It's easily extendable in the future like this, though.
• I've had some issues with getting all tests to run, not sure if this is correct now. Since we need to change the config just for this test, I think setting it like this and resetting at the end is the best way to do it. edit: found the WithConfig.with_config helper that solves my problem 😊
• Probably needs some documentation.

Happy to take it in the direction you want with some pointers 😁

[djfpaagman]

While writing this PR I had another look at my code and realized I can just put a lambda with a method call in the initializer as well:

config.default_from_address = -> { mailer_from }

This works as long as that method exists in the parent mailer, it's the same I do there to set up the default.

I want to keep this PR open though, still think it would be a nice addition!

[mikker]

The tests look like they're failing. I appreciate your efforts and it looks like a good solution - however, I'm hesitant to add code to solve a problem we already, as you noted, has sort of a solution for.

[djfpaagman]

Yeah I'm fine with it working with the lambda now, i'll close this PR 🤘

[mikker]

Thanks!