Added NestedFilter.

Filter/NestedFilterTest.php

+<?php
+
+/*
+ * This file is part of the ONGR package.
+ *
+ * (c) NFQ Technologies UAB <info@nfq.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace ONGR\ElasticsearchBundle\Tests\Unit\DSL\Filter;
+
+use ONGR\ElasticsearchBundle\DSL\Filter\NestedFilter;
+use ONGR\ElasticsearchBundle\DSL\Filter\TermFilter;
+use ONGR\ElasticsearchBundle\DSL\Filter\TermsFilter;
+
+class NestedFilterTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * Tests GetType method.
+     */
+    public function testGetType()
+    {
+        $filter = new NestedFilter('', new TermFilter('foo', 'bar'));
+        $this->assertEquals('nested', $filter->getType());
+    }
+
+    /**
+     * Data provider to testGetToArray.
+     *
+     * @return array
+     */
+    public function getArrayDataProvider()
+    {
+        $filter = [
+            'terms' => [
+                'foo' => 'bar',
+            ],
+        ];
+
+        return [
+            // Case #0 Basic filter.
+            [
+                'product.sub_item',
+                [],
+                ['path' => 'product.sub_item', 'filter' => $filter],
+            ],
+            // Case #1 with parameters.
+            [
+                'product.sub_item',
+                ['_cache' => true, '_name' => 'named_result'],
+                [
+                    'path' => 'product.sub_item',
+                    'filter' => $filter,
+                    '_cache' => true,
+                    '_name' => 'named_result',
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * Test for filter toArray() method.
+     *
+     * @param string $path
+     * @param array  $parameters
+     * @param array  $expected
+     *
+     * @dataProvider getArrayDataProvider
+     */
+    public function testToArray($path, $parameters, $expected)
+    {
+        $query = new TermsFilter('foo', 'bar');
+        $filter = new NestedFilter($path, $query, $parameters);
+        $result = $filter->toArray();
+        $this->assertEquals($expected, $result);
+    }
+}