fix: disregard TypeScript nodes when pruning CSS

[Rich-Harris]

fixes #14204

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[changeset-bot]

🦋 Changeset detected

Latest commit: 1aa8707

The changes in this PR will be included in the next version bump.

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[Rich-Harris]

preview: https://svelte-dev-git-preview-svelte-14276-svelte.vercel.app/

this is an automated message

[github-actions]

Playground

pnpm add https://pkg.pr.new/svelte@14276

[dummdidumm]

This doesn't fix the root cause of the problem, and so other subtle bugs could occur.
Let's say you have this:

<div>
  <p foo={true as false}>hi</p>
</div>

The AST is something like this

{
  type: 'RegularElement',
  name: 'div',
  children: {
    type: 'RegularElement';
    name: 'p';
    parent: the_upper_div_node;
    attributes: [{ type: 'TSASExpression'; ... }]
  }
}

Now if the "strip TS types" visitor runs, it replaces all nodes that have changed nodes etc.
Therefore because TSASExpression is stripped, the p node is replaced with a new object, and so is the div object. But p_node.parent still points to the old div object from before. So now you have two different nodes in there, and p_node.parent !== div_node which is wrong. Just a matter of time until something else goes subtly wrong because of things not matching up correctly - so the fix has to be to rewire p_node.parent to the new div AST node

[Rich-Harris]

merged #14395, closing