SVG via jsdom: error messages cause NaN's

[pkra]

E.g.,

/MathJax-demos-node$ node jsdom/tex2svg "\begin{pkra}x\end{pkra}"

creates

<mjx-container class="MathJax" jax="SVG" display="true"><svg style="vertical-align: -0.452ex;" xmlns="http://www.w3.org/2000/svg" width="NaNex" height="2.149ex" role="img" focusable="false" viewBox="0 -750 NaN 950" xmlns:xlink="http://www.w3.org/1999/xlink"><defs></defs><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="matrix(1 0 0 -1 0 0)"><g data-mml-node="math"><g data-mml-node="merror" data-mjx-error="Unknown environment 'pkra'" title="Unknown environment 'pkra'"><rect data-background="true" width="NaN" height="950" y="-200"></rect><title>Unknown environment 'pkra'</title><g data-mml-node="mtext" style="font-family: serif"><text data-variant="-explicitFont" transform="matrix(1 0 0 -1 0 0)" font-size="884px">\begin{pkra}x\end{pkra} </text></g></g></g></g></svg></mjx-container>

With several NaNs leading to broken output.

[pkra]

The same issue happens for "unknown" characters.

[dpvc]

Thanks, I'll look into it. The jsdom adaptor probably needs to override the functions for measuring the content, as jsdom doesn't set the properties needed for that.

[dpvc]

I've made a PR that addresses the problem. Since jsdom doesn't handle measurements of elements, like a browser DOM, we need to fake the measurements heuristically, like in the liteDOM.