augury for this says "woe"

Elaborate?

I might be amenable if there's no other recourse to a drawAuras hook that passes in the previous slugs as an argument, but doing the computation ourselves in what is already performance sensitive code just in case a module uses it isn't something I could really agree with.

I might be amenable if there's no other recourse to a drawAuras hook that passes in the previous slugs as an argument, but doing the computation ourselves in what is already performance sensitive code just in case a module uses it isn't something I could really agree with.

So using this PR as an example, it would be a hook that provides the preUpdateSlugs and the token that's called after this.draw()?

So something akin to

 async reset(slugs?: string[]): Promise<void> {
        const preUpdateSlugs = Array.from(this.keys());
        
        ...
        
        return this.draw().then(() => Hooks.callAll("drawAuras", this.token, preUpdateSlugs));
}

I would await instead of using then, but yes, though perhaps in an object, so Hooks.callAll("drawAuras", this.token, { preUpdateSlugs }).

I don't mind if its before or after, whichever follows the pattern of most draw/render hooks.

I would use await as well if it was possible to have code run after returning it lol
And I don't know if anything relies on reset() returning that promise.

As for running it before, it sounds somewhat counter to the name of drawAuras

its a Promise<void>. The only reason we return is because returning a promise is the same as awaiting.

The only reason we return is because returning a promise is the same as awaiting.

TIL

Making the changes.

As awkward as it may be to work around, remove the preUpdateSlugs. It has more of a chance going through without it. I'll do research on existing hooks to see if we need to change the name as well.

Placeables have the following hooks
-----------
createX(placeableDocument, options, id) - when placed or created
drawX(placeable, options) - draw function called
refreshX(placeable, options) - ticker updates, usually for animations
hoverX(placeable, options) - when hovering over it
drawX(placeable) - when added or dragged (but only once)
preDeleteX(placeableDocument, options, id)
destroyX(placeable)
deleteX(placeableDocument, options, id)

Documents also have
----------
preUpdateX(actor, updates, flags)
updateX(actor, updates, flags, id)
renderX(app, domElement, getDataResults)

Miscellaneous canvas hooks
------------
initializePointLightSourceShaders(PointLightSource)
lightingRefresh(EffectsCanvasGroup)
sightRefresh(CanvasVisbility)
canvasPan(Canvas, coords)

As a note, I have removed the preUpdateSlugs. The changeset is now just adding a Hooks.callAll("drawAuras", this.token); at the end.

I've reconnected after, and without the diffing of before/after or some way to even store what it was before, this PR has no use. It would be better served by a post prepared hook, which would be able to handle this situation. I'd recommend asking core foundry for such a hook though.