bug#62429: 30.0.50; Add jsx faces to typescript-ts-mode

[Eli Zaretskii]

> From: Yuan Fu <casouri@gmail.com>
> Date: Wed, 29 Mar 2023 17:28:40 -0700
> Cc: monnier@iro.umontreal.ca,
>  62429@debbugs.gnu.org,
>  theo@thornhill.no
> 
> >> JSX is basically HTML mixed with Javascript, so JSX tags and attributes 
> >> are just HTML tags and attributes. Normally it’s fine to just use some 
> >> semi-related font-lock face for them; mhtml.el uses function-call-face and 
> >> constant-face for tags and attributes. But because in JSX, HTML tags and 
> >> attribtues appear in the same buffer with Javascript code, if we use 
> >> function-call-face and constant-face for tags and attributes, it’s 
> >> impossible to change their appearance and not affect the functions and 
> >> constants in Javascript code, because we are using the same face for JS 
> >> functions and HTML tags, and JS constants and HTML attributes.
> > 
> > OK, but then how will these JSX-specific faces fit into the overall
> > scheme of treesit-font-lock faces?  For example, in what level will
> > they be used, and how will users know what level to set to see these
> > faces in their buffers?
> 
> At level 3 for tsx-ts-mode, under the “jsx” feature. So they are enabled by 
> default. Though it’s true that it’s not immediately obvious what face to 
> customize. At the very least these faces appear in the customize group of 
> typescript. We can add something to the docstring of the major mode, too.
> 
> > 
> > These are the downsides of mode-specific faces, and if we think it's
> > important enough to have them, we should resolve these issues when we
> > install such faces.

Then it is fine by me, as long as those measures you mentioned are
taken to make sure users know how to customize font-lock with these
faces.