var matches = require('matches-selector')
  , domify = require('domify');

function assert(expr) {
  if (!expr) throw new Error('assertion failed');
}

var ul = domify('<ul><li><em>foo</em></li></ul>');
var li = ul.children[0];
var em = li.children[0];

describe('matchesSelector(el, selector)', function(){
  it('should work', function(){
    assert(true === matches(em, 'ul li em'));
    assert(true === matches(em, 'ul em'));
    assert(true === matches(em, 'ul > li > em'));
    assert(false === matches(em, 'ul ul em'));

    assert(true === matches(li, 'ul li'));
    assert(true === matches(li, 'ul > li'));
    assert(true === matches(li, 'li'));
    assert(false === matches(li, 'div > li'));

    assert(true == matches(ul, 'ul'));
    assert(false == matches(ul, 'div ul'));
    assert(false == matches(ul, 'body > ul'));
  })
  it('should not throw an Error when given `null`', function(){
    assert(false == matches(null, 'ul'));
  })
  it('should not throw an Error when given a TextNode', function(){
    assert(false == matches(em.firstChild, 'ul'));
  })
})