import { describe, it, expect } from 'vitest';
import { diffManifest } from '../../src/lib/sw/diff-manifest';

describe('diffManifest', () => {
  it('detects new IDs to add', () => {
    const result = diffManifest([1, 2, 3, 4], [1, 2]);
    expect(result.toAdd.sort()).toEqual([3, 4]);
    expect(result.toRemove).toEqual([]);
  });

  it('detects removed IDs', () => {
    const result = diffManifest([1, 2], [1, 2, 3, 4]);
    expect(result.toAdd).toEqual([]);
    expect(result.toRemove.sort()).toEqual([3, 4]);
  });

  it('detects both add and remove in one diff', () => {
    const result = diffManifest([1, 3, 5], [1, 2, 3]);
    expect(result.toAdd).toEqual([5]);
    expect(result.toRemove).toEqual([2]);
  });

  it('returns empty arrays when identical', () => {
    const result = diffManifest([1, 2, 3], [3, 2, 1]);
    expect(result.toAdd).toEqual([]);
    expect(result.toRemove).toEqual([]);
  });

  it('handles empty caches (first sync)', () => {
    const result = diffManifest([1, 2], []);
    expect(result.toAdd.sort()).toEqual([1, 2]);
    expect(result.toRemove).toEqual([]);
  });
});