diff --git a/tests/unit/framework/web/JsonResponseFormatterTest.php b/tests/unit/framework/web/JsonResponseFormatterTest.php
new file mode 100644
index 0000000000..ee43de27b4
--- /dev/null
+++ b/tests/unit/framework/web/JsonResponseFormatterTest.php
@@ -0,0 +1,135 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yiiunit\framework\web;
+
+use yii\base\Object;
+use yii\web\JsonResponseFormatter;
+use yii\web\Response;
+
+class Post extends Object
+{
+    public $id;
+    public $title;
+
+    public function __construct($id, $title)
+    {
+        $this->id = $id;
+        $this->title = $title;
+    }
+}
+
+/**
+ * @author Alexander Makarov <sam@rmcreative.ru>
+ * @since 2.0.3
+ *
+ * @group web
+ */
+class JsonResponseFormatterTest extends \yiiunit\TestCase
+{
+    /**
+     * @var Response
+     */
+    public $response;
+    /**
+     * @var JsonResponseFormatter
+     */
+    public $formatter;
+
+    protected function setUp()
+    {
+        $this->mockApplication();
+        $this->response = new Response;
+        $this->formatter = new JsonResponseFormatter;
+    }
+
+    /**
+     * @param mixed  $data the data to be formatted
+     * @param string $json the expected JSON body
+     * @dataProvider formatScalarDataProvider
+     */
+    public function testFormatScalar($data, $json)
+    {
+        $this->response->data = $data;
+        $this->formatter->format($this->response);
+        $this->assertEquals($json, $this->response->content);
+    }
+
+    public function formatScalarDataProvider()
+    {
+        return [
+            [null, 'null'],
+            [1, 1],
+            ['abc', '"abc"'],
+            [true, 'true'],
+            ["<>", '"<>"'],
+        ];
+    }
+
+    /**
+     * @param mixed  $data the data to be formatted
+     * @param string $json the expected JSON body
+     * @dataProvider formatArrayDataProvider
+     */
+    public function testFormatArrays($data, $json)
+    {
+        $this->response->data = $data;
+        $this->formatter->format($this->response);
+        $this->assertEquals($json, $this->response->content);
+    }
+
+    public function formatArrayDataProvider()
+    {
+        return [
+            [[], "[]"],
+            [[1, 'abc'], '[1,"abc"]'],
+            [[
+                'a' => 1,
+                'b' => 'abc',
+            ], '{"a":1,"b":"abc"}'],
+            [[
+                1,
+                'abc',
+                [2, 'def'],
+                true,
+            ], '[1,"abc",[2,"def"],true]'],
+            [[
+                'a' => 1,
+                'b' => 'abc',
+                'c' => [2, '<>'],
+                true,
+            ], '{"a":1,"b":"abc","c":[2,"<>"],"0":true}'],
+        ];
+    }
+
+    /**
+     * @param mixed  $data the data to be formatted
+     * @param string $json the expected JSON body
+     * @dataProvider formatObjectDataProvider
+     */
+    public function testFormatObjects($data, $json)
+    {
+        $this->response->data = $data;
+        $this->formatter->format($this->response);
+        $this->assertEquals($json, $this->response->content);
+    }
+
+    public function formatObjectDataProvider()
+    {
+        return [
+            [new Post(123, 'abc'), '{"id":123,"title":"abc"}'],
+            [[
+                new Post(123, 'abc'),
+                new Post(456, 'def'),
+            ], '[{"id":123,"title":"abc"},{"id":456,"title":"def"}]'],
+            [[
+                new Post(123, '<>'),
+                'a' => new Post(456, 'def'),
+            ], '{"0":{"id":123,"title":"<>"},"a":{"id":456,"title":"def"}}'],
+        ];
+    }
+}