Support version 3 of MathJax and add config.typesetMath

[archmoj]

TODOs:

• dashboard test using npm run mathjax3
• dashboard example using npm run mathjax3chtml when need to output chtml on the page as well as svg output for plotly graphs | thanks to @akhmerov
• jasmine tests
• add image test using mathjax-v3
• documentation

@plotly/plotly_js

[akhmerov]

Note that this won't work if the page mathjax3 uses a chtml output plugin and AFAIU most people prefer chtml. A workaround requires creating a separate virtual document for MathJax to use in typesetting, see #4563 (comment) for a prototype implementation.

EDIT: Also #4563 should be linked to this PR.

[akhmerov]

Another regression is that compared to the v2 API this doesn't preserve the MathJax settings.

[archmoj]

@akhmerov thanks very much for the notes.
Please see 4ba005f.
With your workaround now one could use npm run mathjax3chtml to test chtml with svg on the same page when _mockedV2API flag is set to true on the MathJax object.

[akhmerov]

Thanks! Note that you don't actually need to mock v2 API to combine the outputs. I mocked the API to make it work with the current plotly implementation and combined with a second virtual document from another recipe. Instead you'll want to use just the recipe from mathjax/MathJax#2705 (comment).

[archmoj]

Thanks! Note that you don't actually need to mock v2 API to combine the outputs. I mocked the API to make it work with the current plotly implementation and combined with a second virtual document from another recipe. Instead you'll want to use just the recipe from mathjax/MathJax#2705 (comment).

Good news. Let me fix that part then :)

[archmoj]

@akhmerov the PR is ready for your review :)

[alexcjohnson]

Looks good! Only the question about inlineMath delimiters is blocking.

@akhmerov thanks for the reviews! Re: tex2svgPromise, I think we should merge with the current structure, but if performance becomes a concern it's good to know this is an option.

[archmoj]

@alexcjohnson this PR is pretty much ready for the final review.
Thank you!

[alexcjohnson]

💃 Very nice work!