next.js 15 playwright testmode onFetch wrapper

handlers.ts

const AUTH_USER_ENDPOINT = /\/auth\/v1\/user/;

export const userRemote = (email: string) => ({
  method: 'GET',
  route: AUTH_USER_ENDPOINT,
  response: {
    data: {
    id: 'uuid',
    email,
    role: 'authenticated',
    user_metadata: {
      email,
    },
    app_metadata: {
      provider: 'email',
    }
  },
});

export const userRemoteNotFound = {
  method: 'GET',
  route: AUTH_USER_ENDPOINT,
  response: {data: null, options: {status: 404}},
};

next.ts

import type {NextFixture} from 'next/dist/experimental/testmode/playwright';

export default function mockFetch(
  next: NextFixture,
  handlers: {method: string; route: RegExp; response: {data: any; options?: any}}[]
) {
  next.onFetch((request: Request) => {
    for (let i = 0; i < handlers.length; i++) {
      if (
        request.method === handlers[i].method &&
        request.url.match(handlers[i].route)
      ) {
        return new Response(JSON.stringify(handlers[i].response.data), {
          headers: {
            'Content-Type': 'application/json',
          },
          ...(handlers[i].response.options ?? {}),
        });
      }
    }
    // EXCLUDED_URLS contains a regex of paths I would allow through such as Google Analytics or logging services 
    if (request.url.match(EXCLUDED_URLS)) {
      return 'continue';
    }
    console.log(`No handler for ${request.method} ${request.url.split('?')[0]}`);
    return 'abort';
  });
}