[v2.x] fix: type error by changing page props type to any

[peaklabs-dev]

Changes

• fix: type errors. Example error: Type unknown is not assignable to type boolean. I get this error (and more for each line) when trying to use $page.props.username, because props are by default typed to unknown.

Example

Example 1:

    type FormValues = {
        username: string;
        notifications_enabled: boolean;
    };

    const defaultValues: FormValues = {
        username: $page.props.username,
        notifications_enabled: $page.props.notifications_enabled,
    };

Example 2:

• Showing a flash message in svelte (I am aware I can get the flash message via $props() in svelte and type it there or leave it, which works because $props() has type of any). The following should be possible, but it is not currently, as I get type errors.

    {#if $page.props.flash.message}
      <div class="alert">{$page.props.flash.message}</div>
    {/if}

[pascalbaljet]

I don't like to change this across all adapters, as in React/Vue you can do usePage<PageProps>(). Also, unknown in this case is preferred over any. Can't we make the change in packages/svelte/src/page.ts?

type SveltePage = Omit<Page, 'props'> & {
  props: Page['props'] & {
    [key: string]: any
  }
}

const { set, subscribe } = writable<SveltePage>()

[peaklabs-dev]

@pascalbaljet Thanks for the review. I have changed it, let me know if anything else is needed.

[pascalbaljet]

Thanks! I've added a test so we know it keeps working in the future.