Why should m.request and m.jsonp be split?

[dead-claudia]

Description

Currently, m.request and m.jsonp are split. This was introduced in v1 per #1068

I'm proposing for v3, let's move that back to m.request via the special method: "JSONP" (case-insensitive). We'd just ignore callbackKey and callbackName for non-JSONP requests, and user-visible handling is otherwise identical.

Why

Leo's justification doesn't really hold up from a usability perspective. It really feels like it's leaking an implementation detail.

Plus, with modern CORS, JSONP has mostly just disappeared now, so we might be able to get away with just dropping it. It's been literally years since I've last needed to make a script request, and CORS is fully supported in IE10+. If we really wanted to support IE8-9, we could fall back to XDomainRequest on network failure for partial support, at the cost of moderately increased latency for those two browsers specifically. (It supports about 80% of XHR's API.)

Possible Implementation & Open Questions

The implementation is self-explanatory. The main question of this bug is really this: do we want to keep them separate, combine them, or drop m.jsonp's functionality altogether?

Is this something you're interested in working on?

Yes