Article.php

<?php
App::uses('AppModel', 'Model');
/**
 * Article Model
 *
 * @property Comment $Comment
 */
class Article extends AppModel {

/**
 * Validation rules
 *
 * @var array
 */
	public $validate = array(
	);

/**
 * hasMany associations
 *
 * @var array
 */
	public $hasMany = array(
		'Comment' => array(
			'className' => 'Management.Comment',
			'foreignKey' => 'article_id',
			'dependent' => false,
			'conditions' => '',
			'fields' => '',
			'order' => '',
			'limit' => '',
			'offset' => '',
			'exclusive' => '',
			'finderQuery' => '',
			'counterQuery' => ''
		)
	);
}

ArticleFixture.php

<?php
/**
 * ArticleFixture
 *
 */
class ArticleFixture extends CakeTestFixture {

/**
 * Fields
 *
 * @var array
 */
	public $fields = array(
		'id' => array('type' => 'integer', 'null' => false, 'default' => null, 'unsigned' => false, 'key' => 'primary'),
		'title' => array('type' => 'string', 'null' => false, 'default' => null, 'collate' => 'utf8_general_ci', 'charset' => 'utf8'),
		'body' => array('type' => 'text', 'null' => true, 'default' => null, 'collate' => 'utf8_general_ci', 'charset' => 'utf8'),
		'created' => array('type' => 'datetime', 'null' => true, 'default' => null),
		'modified' => array('type' => 'datetime', 'null' => true, 'default' => null),
		'indexes' => array(
			'PRIMARY' => array('column' => 'id', 'unique' => 1)
		),
		'tableParameters' => array('charset' => 'utf8', 'collate' => 'utf8_general_ci', 'engine' => 'InnoDB')
	);

/**
 * Records
 *
 * @var array
 */
	public $records = array(
		array(
			'id' => 1,
			'title' => 'Lorem ipsum dolor sit amet',
			'body' => 'Lorem ipsum dolor sit amet, aliquet feugiat. Convallis morbi fringilla gravida, phasellus feugiat dapibus velit nunc, pulvinar eget sollicitudin venenatis cum nullam, vivamus ut a sed, mollitia lectus. Nulla vestibulum massa neque ut et, id hendrerit sit, feugiat in taciti enim proin nibh, tempor dignissim, rhoncus duis vestibulum nunc mattis convallis.',
			'created' => '2014-10-09 20:34:42',
			'modified' => '2014-10-09 20:34:42'
		),
	);

}

ArticlesController.php

<?php
App::uses('AppController', 'Controller');
/**
 * Articles Controller
 *
 */
class ArticlesController extends AppController {
	public $components = ['RequestHandler', 'Flash'];

	public function add() {
		$resp = [];
		if ($this->request->is('post')) {
			$resp = $this->Article->save($this->request->data);
		}
		$this->set('article', $resp);
		$this->set('_serialize', ['article']);
	}
}

ArticlesControllerTest.php

<?php
App::uses('ArticlesController', 'Controller');

/**
 * ArticlesController Test Case
 *
 */
class ArticlesControllerTest extends ControllerTestCase {

/**
 * Fixtures
 *
 * @var array
 */
	public $fixtures = array(
		'app.article',
	);

	public function testAdd()
	{
		$url = Router::url(array(
			'controller' => 'articles',
			'action' => 'add',
			'ext' => 'json',
		));
		$options = array(
			'return' => 'contents',
			'method' => 'POST',
			'data' => [
				'Article' => [
					'title' => 'testing',
					'body' => 'testing body',
				]
			]
		);
		$result = $this->testAction($url, $options);
		debug($result);
	}
}

routes.php

<?php
	Router::parseExtensions('json');

	Router::connect('/', array('controller' => 'pages', 'action' => 'display', 'home'));

	Router::connect('/pages/*', array('controller' => 'pages', 'action' => 'display'));
	
	CakePlugin::routes();
	require CAKE . 'Config' . DS . 'routes.php';