Mailjet webhook events fail when not grouped

[prettyv]

Currently (django-anymail v2.2) produces a TypeError when an event type is not configured to be grouped in Mailjet's event trigger settings. This is because the Mailjet webhook handling assumes the body to always be a JSON list containing all events although this is not the case when an event type is not marked to "Group events", which will send each event individually as a JSON dict.
This leads to TypeError: string indices must be integers in webhooks/mailjet.py:57 since esp_event is now a string (key of the event dict).

I guess the reason it is currently implemented like this is that it seems like the official documentation doesn't actually consider this and just says All the events will be delivered to your webhook in a JSON array of event objects. (https://dev.mailjet.com/guides/#endpoint-url)

[medmunds]

Thanks for reporting this. Mailjet event grouping is recommended, but Anymail should support it either way, so this is a bug.

(And you're right: I interpreted the docs the same way you did, and never tested without "Group events" enabled. I should really know better than to trust ESP documentation by now. :-))

[prettyv]

That was quick, thanks a lot! 😄

[medmunds]

Fix released in Anymail v3.0.