/**
* @covers WPSEO_Frontend::flush_cache
*/
public function test_flush_cache()
{
$c = self::$class_instance;
// should not run when output buffering is not turned on
$this->assertFalse(self::$class_instance->flush_cache());
// turn on output buffering
self::$class_instance->force_rewrite_output_buffer();
$content = '<!DOCTYPE><html><head><title>TITLETOBEREPLACED</title>' . self::$class_instance->debug_marker(false) . '</head><body>Some body content. Should remain unchanged.</body></html>';
// create expected output
global $sep;
$title = self::$class_instance->title('', $sep);
$expected = preg_replace('/<title(.*)\\/title>/i', '', $content);
$expected = str_replace($c->debug_marker(false), $c->debug_marker(false) . "\n" . '<title>' . $title . '</title>', $expected);
echo $content;
// run function
$result = self::$class_instance->flush_cache();
// run assertions
$this->expectOutput($expected, $result);
$this->assertTrue($result);
}