When I attempt to extend HTMLAttributes every intrinsic element becomes of type any

[Zequez]

This is the type declaration I'm using:

import { JSXInternal as JSXI } from 'preact/src/jsx';

declare module 'preact/src/jsx' {
  namespace JSXInternal {
    interface HTMLAttributes<T> extends JSXI.HTMLAttributes<T> {
      class?: any;
    }
  }
}

Essentially what I want to do is to extend the HTMLAttributes in order to be able to pass any type to the "class" attribute so I can then process it on the options.vnode hook; however when I use this declaration every element becomes of type any.

There was a long discussion a couple of years ago with something similar, but it was for extending IntrinsicElement not HTMLAttributes, and that thread is how I arrived to the current shape of the declaration file.

[rschristian]

I believe this is what you want instead:

interface MyCustomProps {
  class?: any;
}

declare module 'preact' {
  namespace JSX {
    interface IntrinsicAttributes extends MyCustomProps {}
  }
  interface Attributes extends MyCustomProps {}
}

export {};

[JoviDeCroock]

Closing as answered - feel free to open things like this in discussions in the future, as these are more questions rather than issues.