Preserve tag name cases

[quadratz]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and couldn’t find anything (or linked relevant results below)

Problem

Add an option to preserve the case of HTML tags. This is similar to issue #18, but for HTML tags in general.

Currently, this

{
      "type": "raw",
      "value": "<TabGroup><Tab lang='js' title='JavaScript' /></TabGroup>",     
}

will yield

 {
      "type": "element",
      "tagName": "tabgroup",
      // ...
 }

Solution

TabGroup and Tab should be cased.
It should produce this output instead

 {
      "type": "element",
      "tagName": "TabGroup",
      // ...
 }

[ChristianMurphy]

Welcome @quadratz! 👋
HTML is case insensitive, there are no plans to add non-html features to the HTML parser.
It looks like you may be working with XML or JSX.
If you are working with XML consider using https://github.com/syntax-tree/xast-util-from-xml
If you are working with JSX+Markdown consider using https://mdxjs.com/

[quadratz]

I think https://mdxjs.com/ is more suitable for my case. Thank you for the help.