Cannot add scopes as described in the docs

[rhufsky]

Environment

  System:
    OS: macOS 15.1.1
    CPU: (8) arm64 Apple M1 Pro
    Memory: 710.05 MB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 22.12.0 - /opt/homebrew/opt/node@22/bin/node
    npm: 10.9.0 - /opt/homebrew/opt/node@22/bin/npm
    pnpm: 9.15.0 - /opt/homebrew/bin/pnpm
    bun: 1.1.40 - /opt/homebrew/bin/bun
  Browsers:
    Chrome: 131.0.6778.205
    Safari: 18.1.1
  npmPackages:
    next: 15.1.3 => 15.1.3 
    next-auth: ^5.0.0-beta.25 => 5.0.0-beta.25 
    react: ^19.0.0 => 19.0.0 

Reproduction URL

https://github.com/rhufsky/authdemo

Describe the issue

The document https://authjs.dev/guides/configuring-oauth-providers states that requesting additional scopes can be implemented by just adding a property to the provider like so:

    GitLab({
      authorization: {
        params: { scope: "read_user api" },
      }
    }),

The modified properties should be deep merged into the defaults.

In reality, when doing this, i get an exception like this at login time:

[auth][error] TypeError: Invalid URL
    at new URL (node:internal/url:818:25)
    at getAuthorizationUrl (/Users/rhufsky/Documents/Development/HTL-IT/Experimental-Applications/authdemo/.next/server/chunks/ssr/node_modules_c31d8c._.js:11189:24)

Adding the original AUTH_URL to the config solves the problem, so no deep merging, at least in the Gitlab Provider.

const GITLAB_OAUTH_SCOPES = "read_user";
const GITLAB_AUTH_URL = "https://gitlab.com/oauth/authorize";

export const { handlers, auth, signIn, signOut } = NextAuth({
  providers: [
    GitLab({
      authorization: {
        url: GITLAB_AUTH_URL,
        params: { scope: GITLAB_OAUTH_SCOPES },
      },
    }),
  ],

How to reproduce

In the sample, comment out url: GITLAB_AUTH_URL, and try top log in.

Expected behavior

In should not be neccesary to add url: GITLAB_AUTH_URL, when I want to configure scopes.