Move to MathJax 3.

[hameerabbasi]

Subject: Move to MathJax 3 in Sphinx 4.0

Feature or Bugfix

• Feature

Purpose

To use MathJax 3 and all its new features.

Relates

Closes #7425

[mitya57]

According to https://caniuse.com/#feat=es6, ES6 is supported by 96.71% of users' browsers. Maybe the polyfill is not needed?

[tk0miya]

How about adding mathjax_version = (2 | 3) to Sphinx-3.x (of course, default is 2). Then who want to use mathjax-3 can start to use sooner. And we'll switches the default to 3 since Sphinx-4.0 release.

[hameerabbasi]

How about adding mathjax_version = (2 | 3) to Sphinx-3.x (of course, default is 2). Then who want to use mathjax-3 can start to use sooner. And we'll switches the default to 3 since Sphinx-4.0 release.

This is already possible just by switching the mathjax_path config. Would you prefer I document that for version 3.x?

[tk0miya]

Indeed. Please forget. I'm afraid to introduce a breaking change in 4.0. But I understand it is hard to reduce the impact (mainly for mathjax customized users). So +1 for this change.
It would be helpful to me if you add a CHANGES entry (because I'm not a native English speaker).

[tk0miya]

According to https://caniuse.com/#feat=es6, ES6 is supported by 96.71% of users' browsers. Maybe the polyfill is not needed?

Is this done?

[hameerabbasi]

Is this done?

Yes.

[tk0miya]

LGTM!

@mitya57 Do you have any comments?

[hameerabbasi]

I'm not sure how to get the line length down while keeping the link. Thoughts?

[mitya57]

One minor suggestion, otherwise it looks good to me.

[tk0miya]

Now I updated a linter rule on #8002. Could you merge the 3.x branch and fold the line before an URL? It allows a very long literal string.

[hameerabbasi]

There are a bunch of merge conflicts I'm not skillful enough to resolve... Should I cherry-pick the commit?

[tk0miya]

Oh, sorry. Please wait a moment. I'll merge in into master branch.

[tk0miya]

Done. Please merge the master branch into this.

[tk0miya]

Thank you for your contribution! Merged 🎉