export default async function runWithPerfBudget(fn, budgetMs, now) {
  throw new Error('Not implemented');
}

import runWithPerfBudget from './runWithPerfBudget';

describe('runWithPerfBudget', () => {
  test('times sync functions and returns ok status', async () => {
    const times = [100, 112];
    const now = () => times.shift();

    const res = await runWithPerfBudget(() => 123, 20, now);
    expect(res).toEqual({ ok: true, durationMs: 12, value: 123 });
  });

  test('times async functions and awaits the result', async () => {
    const times = [0, 50];
    const now = () => times.shift();

    const res = await runWithPerfBudget(async () => 'ok', 40, now);
    expect(res.ok).toBe(false);
    expect(res.durationMs).toBe(50);
    expect(res.value).toBe('ok');
  });

  test('clamps negative duration to 0', async () => {
    const times = [10, 5];
    const now = () => times.shift();

    const res = await runWithPerfBudget(() => 'x', 0, now);
    expect(res.durationMs).toBe(0);
    expect(res.ok).toBe(true);
  });

  test('throws on invalid inputs', async () => {
    await expect(runWithPerfBudget(null, 1)).rejects.toThrow();
    await expect(runWithPerfBudget(() => 1, -1)).rejects.toThrow();
  });
});