Why is event.params.[paramName] possibly undefined when used inside actions and not when used inside the load function?

[dadezzz]

For example:

// /product/[slug]/+page.server.ts

export const load: PageServerLoad = (event) => {
  // slug is not undefined
  const product = productsBySlug[event.params.slug];
}

export const actions: Actions = {
  default: (event) => {
    // typescript complains because slug is possibly undefined
    const product = productsBySlug[event.params.slug];
  }
}

[geodask]

[brunnerh]

That logic does not quite make sense. To trigger the action you have to send a request to the route, including the parameters associated with it.

[geodask]

Sorry, I accidentally deleted the original answer. You're absolutely right, I overlooked that. To clarify further, I checked on my side, and params.slug is not undefined; it's correctly typed. Perhaps this behavior is related to the version of SvelteKit being used.

[dadezzz]

That's strange, I'm using the latest version and it still happens.

I'll see if I can create a minimal reproduction later.

[geodask]

Make sure you are importing Actions like this:

import { Actions } from "./$types";

and not

import { Actions } from "@sveltejs/kit";

In this way you will get the route specific types.

[dadezzz]

oh, that solved the problem, thank you!