Isolated AsyncLocalStorage Context Injection for Next.js Server Action Unit Testing

import { AsyncLocalStorage } from 'node:async_hooks';
import test from 'node:test';
import assert from 'node:assert';
 
export const requestStore = new AsyncLocalStorage<{ requestId: string }>();
 
export async function logServerAction(actionName: string) {
  const store = requestStore.getStore();
  if (!store) throw new Error('Action invoked outside request context');
  return `[${store.requestId}] Executed ${actionName}`;
}
 
test('runs server action with injected trace context', async () => {
  const result = await requestStore.run({ requestId: 'req_123' }, () =>
    logServerAction('updateUser')
  );
  assert.strictEqual(result, '[req_123] Executed updateUser');
});