import { describe, expect, it } from 'vitest';
import { elapsedSeconds, formatTime } from './stopwatch';

describe('stopwatch logic', () => {
  it('formats seconds as HH:MM:SS', () => {
    expect(formatTime(0)).toBe('00:00:00');
    expect(formatTime(65)).toBe('00:01:05');
    expect(formatTime(3661)).toBe('01:01:01');
  });

  it('computes elapsed seconds since start excluding paused time', () => {
    expect(elapsedSeconds(1000, 6000, 0)).toBe(5);
    expect(elapsedSeconds(1000, 6000, 2000)).toBe(3);
  });

  it('never returns a negative elapsed value', () => {
    expect(elapsedSeconds(5000, 1000, 0)).toBe(0);
  });
});