Force svelte not to interpret some classes

[tobiasBora]

When using rehype-katex, it generates text like:

<div class="math math-inline">
 … some stuff involving {x} that is interpreted by svelte
</div>

and it produces error as {x} usually comes from a math expression like \sqrt{x} and is not meant to be replaced as a svelte variable. People created a rehype-katex-svelte (as recommended in #302) to solve this issue and this seems to work reasonably well, but I don't know how well maintained this is (e.g. it requires a quite old remark-math, but so do rehype-katex so it might be unrelated) and the author mention some potential security flows. As such, it seems not at battle-tested as rehype-katex.

As such, I was wondering if would instead directly allow users to add in MDsveX (via the options) a list of classes that should be wrapped around {@html } appropriately (with escaping etc) in order not to be interpreted by svelte later in the process. As rehype-katex does not want to do it on their side (see remarkjs/remark-math#104), I see not much other solution, and this might anyway be useful in other scenarios.

[PeppeL-G]

Haven't thought much about this, but for a general functionality of "escaping" Svelte code, wouldn't a custom remark-directive named notSvelte or similar be a good solution? Where theContent in the directive is replaced with @html{`theContent`}, and that can be used like this:

Between the square brackets :notSvelte[in here using { and } works].

::notSvelte[In here using { and } works.]

:::notSvelte

In here, using { and } works.

:::

In VuePress, they do something like that:

https://vuepress.vuejs.org/guide/using-vue.html#escaping

::: v-pre
`{{ This will be displayed as-is }}`
:::

[tobiasBora]

Hum, that is also an interesting option (we can even nest ::notSvelte and ::svelte), but I'd say that both would be interesting: what you describe is cool to escape any code easily with no configuration, but is quite verbose and error-prone when used for math: I don't want to type in the markdown directly ::notSvelte[$a+b$] everytime I write some math as this is just too verbose. The class-based approach is useful when we don't want/can't change the markdown itself as the code is generated from an external library like Katex.