renderToString( h( undefined ) ) returns [object Object]

[meyer]

Not sure if this is a preact issue or a preact-render-to-string issue, but I’ll put it here for now.

A component I wrote wasn’t being exported properly (long story) and the result was undefined instead of a valid component. I thought it was a React alias issue like I saw in a few other issues, but after digging through my bundle I determined that that was not the case.

Seems to me that either h(undefined) or renderToString( h(undefined) ) should throw an error.

[csantany]

+1 I have the same problem

[developit]

Good point, and I agree - render(h(undefined)) renders <undefined /> in Preact itself, so maybe we emulate that here? It certainly gives a good idea of where the undefined entity came into existence.

The offending code is here: https://github.com/developit/preact-render-to-string/blob/master/src/index.js#L66

Likely the solution is change L66 to:

if (typeof vnode!=='object' && !nodeName) {

[developit]

I've opened #47 that fixes this, if either of you could review that would be great!