inferno4 {0} not rendered in DOM

[kurdin]

Not sure why I have this problem but I have pager component with variable z === 0 it was renders fine in DOM in inferno3. Now after inferno4 upgrade I need to add {variable + ''} to make sure 0 is visible.

Strange thing that I could not reproduce this on here: https://jsfiddle.net/vrydxohy/
and React 16 renders 0 just fine: https://jsfiddle.net/sfbg7eL3/

Who is responsible for not rendering 0 into DOM HTML ? it does not look like inferno4 problem and I use latest babel-plugin-inferno and babel-plugin-syntax-jsx packages.

[Havunen]

I have never seen this before. We need steps to reproduce to be able to identify the issue.

[kurdin]

@Havunen
After few hours of digging thru few handers of files in our app, I finally found the problem.

We use inferno-compat in few places for findDOMNode and React.cloneElement in packages that we converted from react. So it turns out if you simple import inferno-compat anywhere in your app along with inferno then {0} wont be rendered in DOM in any component of app. Strange but looks like a bug in inferno-compat.

Here is example, I just included inferno-compat via script and {0} wont work anymore.

https://jsfiddle.net/nLjoyfe2/

[Havunen]

Yeah this is bug, also there seems to be performance issue in inferno-compat. It seems like in inferno-compat arrays fall into iterableToArray code path as arrays are iterables too. Need to fix that. The actual bug is also there:

https://github.com/infernojs/inferno/blob/master/packages/inferno-compat/src/index.ts#L192-L194

Let's hotfix this.

[kurdin]

@Havunen We trying to avoid using inferno-compat but sometimes it is quicker to convert some functionality from React.

What would be alternative for React.cloneElement in inferno4 ?

[Havunen]

@kurdin

It depends: if all you want is clone and assign props, then you can use const copy = Inferno.directClone(vNode); and maybe Object.assign props into copied vNode. If you want same API then you can use inferno-clone-vnode package its drop in replacement

[Havunen]

Just released 4.0.7 this is fixed there. Thanks for reporting the issue. Closing