import { test } from 'node:test';
import assert from 'node:assert/strict';
import { dedupeInFlight } from './inFlight';

test('dedupeInFlight: one request per key while pending, a new one after (#318)', async () => {
  const once = dedupeInFlight<number>();
  let calls = 0;
  let release!: () => void;
  const gate = new Promise<void>((r) => {
    release = r;
  });
  const run = async () => {
    calls += 1;
    await gate;
    return calls;
  };
  const a = once('d1', run);
  const b = once('d1', run);
  const c = once('d2', run);
  assert.equal(a, b);
  release();
  assert.deepEqual(await Promise.all([a, b, c]), [2, 2, 2]);
  assert.equal(calls, 2);
  await once('d1', run);
  assert.equal(calls, 3, 'settled requests are not reused');
});

test('dedupeInFlight: a rejection clears the key', async () => {
  const once = dedupeInFlight<void>();
  await assert.rejects(once('k', () => Promise.reject(new Error('boom'))));
  await once('k', () => Promise.resolve());
});