import { test } from 'node:test';
import assert from 'node:assert/strict';
import { wrapIndex } from './carousel.logic.ts';

test('wrapIndex is identity within range', () => {
  assert.equal(wrapIndex(0, 3), 0);
  assert.equal(wrapIndex(2, 3), 2);
});

test('wrapIndex wraps forward past the last frame to the first', () => {
  assert.equal(wrapIndex(3, 3), 0);
  assert.equal(wrapIndex(4, 3), 1);
});

test('wrapIndex wraps backward past the first frame to the last', () => {
  assert.equal(wrapIndex(-1, 3), 2);
  assert.equal(wrapIndex(-2, 3), 1);
});