Brevo webhook updates

[originell]

rel #385

As talked about in the related issue, I've updated the mappings. I also added tests and docs.

Furthermore, I tried to make the code comment I missed ( "request" event) stand out more, by moving all the comments from inline to above their related entry. I hope this is OK.

Very much looking forward to your comments!

[originell]

A question: while testing the new mappings, I noticed that Brevo had some problems with the proxy_open event. Hence, I contacted their support and I've received this as an answer:

The team has confirmed that they needed to make a few database changes so that this event type could be added to our collections.
We have made changes for you and you should now receive “unique_proxy_open” for the first/unique opening.
For subsequent openings, you will receive “proxy_open” events.

Now, I am asking myself: should I also supply a mapping for unique_proxy_open as well?

It is undocumented and I've only gotten access to this by asking support.

[medmunds]

Thanks, your updates look great.

should I also supply a mapping for unique_proxy_open as well?

Yes. (I think.)

I'd guess that proxy_open and unique_proxy_open will parallel opened and unique_opened, so mapping both will be necessary to receive all the proxy open events.

We ended up normalizing both of the original "opened" to Anymail's OPENED, and added this paragraph to the docs about how to choose. See #344 if you're interested in the history.

# Sadly, this is not well documented in the official Brevo API documentation.

I may get that printed on a T-shirt 😄. (Not to pick on Brevo: pretty much every ESP's documentation for webhooks is some combination of incomplete and just plain inaccurate.)

[originell]

Thanks for the feedback! I've now added the suggested changes.

Let me know if something could be done better!

[medmunds]

That's great, thanks. I updated the docs to combine some of the earlier information about open events with your new information.

(Also, nice work debugging Brevo's proxy open behavior and the missing unique_proxy_open event!)

[originell]

Perfect! Thanks for merging those. Sounds way better that way.

nice work debugging Brevo's proxy open behavior

Haha thanks. But that was more people work than debugging work. Their support was very helpful though. Wasn't more than 2-3 emails.