public function testAttr()
{
$el = new Element(['title' => 'Hello']);
$this->assertEquals('<div title="Hello"></div>', (string) $el);
$this->assertEquals('Hello', $el->attr('title'), '.attr( attributeName ) returns the attribute');
$this->assertEquals(null, $el->attr('foo'));
//
$el->attr(['disabled', 'title' => 'Goodbye']);
$this->assertEquals('<div title="Goodbye" disabled></div>', (string) $el, '.attr( attributes ) set the attribute value');
$this->assertTrue($el->attr('disabled'), 'attributes without value are converted to (boolean) true');
$el->attr('title', 'Changed');
$this->assertEquals('<div title="Changed" disabled></div>', (string) $el, '.attr( attribute, value) set the attribute');
$el->attr('disabled', '')->attr('title', 'Chained');
$this->assertEquals('<div title="Chained"></div>', (string) $el, '.attr( attribute, "") removed the attribute');
}
