Request more control over escaping

[johnhooks]

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

I'm using toHtml to stringify highlighted code elements and then use them in MDsveX, a Svelte version of MDX. Though I need to escape [{}`] because those are special characters in Svelte. I was attempting to escape them at the base of the AST on the text values. But I they were getting double escaped. I then figured out toHtml escapes &.

Currently, I'm running the hast through toHTML and then escaping the other characters I need. Though this seems brittle and also much less targeted than having control at the Text.value level.

Solution

• make it possible to disable escaping in toHtml
• expose a escape option that allows overriding the default.

Alternatives

• add the ability to add characters to subset

what do you think?

[wooorm]

This project focusses on standards, not on custom non-standard needs.

Disabling escaping would break everything. Allowing to override escape would break everything.

I don’t think this feature would be enough for you to generate a string for Svelte.
Also sounds like you don’t generate things for Svelte, but for MDsveX. Which is even more different.

What do you want to generate? Why use this project for that? Why not build your own project for Svelte/MDsveX’s format?
Why not use MDX itself, which also works with Svelte?

[johnhooks]

I am using this library to generate strings of highlighted code elements from MDSveX fenced code blocks. I'm using hastscript to build the hast AST from Shiki generated tokens. It's not necessarily generating anything MDsveX or Svelte specific, but since its processed by MDsveX after being generated, braces need to be escaped.

Everything is currently working beautifully, but I would like more control over escaping special characters. Like I said I thought adding subset would be better and wasn't sure why the option was disabled. I didn't believe I was inquiring on something that was non-standard, the ability to control which characters of a text value in HTML to escape seemed like it would be a common need.

[ChristianMurphy]

HTML and Svelte templates are related but different, I'd agree with @wooorm that this project focuses HTML, adding Svelte specific escapes doesn't make sense.
A pipeline which would likely make more sense for your use case.

• Start with the Shiki tokens
• Generate a hast tree
• Translate the hast tree to a svast tree https://github.com/pngwn/MDsveX/tree/master/packages/svast
• serialize the svast tree with svast-stringify https://github.com/pngwn/MDsveX/tree/master/packages/svast-stringify

Or alternatively:

• Start with the Shiki tokens
• Generate a svast tree https://github.com/pngwn/MDsveX/tree/master/packages/svast
• Serialize the svast tree with svast-stringify https://github.com/pngwn/MDsveX/tree/master/packages/svast-stringify

In both cases, using svast-stringify should guarantee compatibly with MDsveX, since it is designed/built to implement MDsveX's own internal AST representation and will include escapes expected by MDsveX.

[johnhooks]

@ChristianMurphy and @wooorm thanks for the advice. I'll take a look at building a svast tree, rather than hast.