useSearchState() hook: ReadonlyURLSearchParams is missing property size

[bencmbrook]

Verify canary release

• I verified that the issue exists in the latest Next.js canary release

Provide environment information

Operating System:
      Platform: darwin
      Arch: x64
      Version: Darwin Kernel Version 22.5.0: Thu Jun  8 22:22:22 PDT 2023; root:xnu-8796.121.3~7/RELEASE_X86_64
    Binaries:
      Node: 18.16.0
      npm: 9.5.1
      Yarn: 1.22.19
      pnpm: N/A
    Relevant Packages:
      next: 13.4.12
      eslint-config-next: 13.0.0
      react: 18.2.0
      react-dom: 18.2.0
      typescript: 4.9.5
    Next.js Config:
      output: N/A

Which area(s) of Next.js are affected? (leave empty if unsure)

Routing (next/router, next/navigation, next/link)

Link to the code that reproduces this issue or a replay of the bug

https://codesandbox.io/p/sandbox/aged-sunset-4s55pr?file=%2Fapp%2Fpage.tsx%3A12%2C30

To Reproduce

You will notice this in TypeScript when trying to construct URLSearchParams from the value returned by useSearchParams().

import { usePathname, useRouter, useSearchParams } from 'next/navigation';

In your component

  const searchParams = useSearchParams();
  const params = new URLSearchParams(searchParams);
                                     ^^^^^^^^^^^^^

Argument of type 'ReadonlyURLSearchParams' is not assignable to parameter of type 'string | string[][] | Record<string, string> | URLSearchParams | undefined'.
Property 'size' is missing in type 'ReadonlyURLSearchParams' but required in type 'URLSearchParams'.

Describe the Bug

The URL Standard expects URLSearchParams to have the size property, but ReadonlyURLSearchParams is missing this property.

This is a relatively new addition to the spec.

This causes a Type Error when attempting to construct URLSearchParams from ReadonlyURLSearchParams, as recommended in the Next docs here.

This breaks next build on Node v18.16.0+, including on Vercel

Expected Behavior

ReadonlyURLSearchParams has property size, which returns the list's size. (Here)

Which browser are you using? (if relevant)

No response

How are you deploying your application? (if relevant)

No response

[bencmbrook]

Found a duplicate #49774

[github-actions]

This closed issue has been automatically locked because it had no new activity for a month. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.