Restore Vue 3 usePage generic type

[jessarcher]

When converting the adapters to TypeScript, I forgot to copy over the existing type definition for usePage which used a generic.

This PR attempts to restore this, however, I can't currently get it to build.

Fixes #1381

[hailwood]

@jessarcher just a note to please check the other adapters too.
I can confirm that the same issue applies to the react adapter.

[jessarcher]

@jessarcher just a note to please check the other adapters too. I can confirm that the same issue applies to the react adapter.

Good call! Looks like #1396 beat me too it though :)

[reinink]

@innocenzi Hey! We've got this particular issue fixed in #1396 for React, but we're struggling to know exactly how to do this in the Vue adapters. We're getting this error:

src/app.ts:119:3 - error TS2322: Type '{ component: string; props: { [x: string]: unknown; errors: Errors & ErrorBag; }; url: string; version: string; scrollRegions: { top: number; left: number; }[]; rememberedState: Record<string, unknown>; resolvedErrors: Errors; }' is not assignable to type 'Page<T>'.
  Types of property 'props' are incompatible.
    Type '{ [x: string]: unknown; errors: Errors & ErrorBag; }' is not assignable to type 'PageProps & T & { errors: Errors & ErrorBag; }'.
      Type '{ [x: string]: unknown; errors: Errors & ErrorBag; }' is not assignable to type 'T'.
        'T' could be instantiated with an arbitrary type which could be unrelated to '{ [x: string]: unknown; errors: Errors & ErrorBag; }'.

119   return page.value
      ~~~~~~~~~~~~~~~~~


Found 1 error in src/app.ts:119

Do you have any recommendations on how to fix this?

[innocenzi]

@reinink Looks like the page variable is the culprit; it has a generic type of Page but the generics are not constrained. I think using const page = ref<Page<any>>() would fix it. But I also recommend constraining the generics of usePage:

// in Vue
export function usePage<T extends PageProps>(): Page<T> {
  return page.value
}

// and in core
export interface Page<SharedProps extends PageProps = PageProps> {
  // ...
}

[libero-developer]

Any news on this?