Separate root and child functions

[mcordova47]

Adds a Wrapper class, with two instances for root and child wrappers. This way, we can encode into the types whether a function has to run on the root wrapper, like update:

I think this should also extend to other things, like:

• Does the function have to run on a single element?
• Shallow vs. Full rendering

But I haven’t thought too much about it, yet.

[fsoikin]

While the single/multiple distinction would indeed be useful, I think the root/child distinction doesn't help with anything. Logically, there is no reason functions should work differently between child and root elements, and indeed, in your code only the update function actually uses this distinction.

But there is no deep reason that update should be prohibited on child elements. It's just an implementation quirk of Enzyme.

From the end user perspective, update shouldn't even apply to any element in particular. Rather, it should affect "the world" (or, more precisely, the "current simulation").

There is no reason update should be prohibited inside a withSelector, quite the opposite: it creates an inconvenience. Now I have to exit the withSelector context just to call waitUntil

Currently update simply doesn't work inside a withSelector, but instead of explicitly preventing it from being called there, we should make it work. I'm pretty sure there is a way to find the root element by repeatedly calling parent, but even failing that, we can solve this by carrying around not just the "current" element, but the original root as well.

[mcordova47]

I'm pretty sure there is a way to find the root element by repeatedly calling parent, but even failing that, we can solve this by carrying around not just the "current" element, but the original root as well.

But the problem, I think, is how do you get the updated "current" element -- not just how to get the root.

[fsoikin]

Ah, I think there is a bit of misunderstanding here. The update function doesn't return an updated root functional-style, it just mutates the internal state of everything. And you can keep using your existing ElementWrapper objects, they still point to the same DOM elements.

But here's the kicker: apparently the Enzyme team had the same idea 3 years ago. Check this out: enzymejs/enzyme#1802 (comment)

And the comment was updated too: https://github.com/enzymejs/enzyme/pull/1802/files#diff-380144706937206c2b8ef0761bb879bc2c25e6cb11b7b31dd0091e5c690f5fddR226

But the docs are apparently out of date now.

[mcordova47]

Interesting, but then does that mean this already works?

[fsoikin]

Yes, exactly