public function testBrokenLinkHighlighting()
{
$sitetree = new SiteTree();
$editor = new HtmlEditorField('Content');
$editor->setValue('<a href="[sitetree_link id=0]">Broken Link</a>');
$element = new SimpleXMLElement(html_entity_decode((string) new SimpleXMLElement($editor->Field())));
$this->assertContains('ss-broken', (string) $element['class'], 'A broken link class is added to broken links');
$editor->setValue(sprintf('<a href="[sitetree_link id=%d]">Working Link</a>', $this->idFromFixture('SiteTree', 'home')));
$element = new SimpleXMLElement(html_entity_decode((string) new SimpleXMLElement($editor->Field())));
$this->assertNotContains('ss-broken', (string) $element['class']);
}
