diff --git a/.gitignore b/.gitignore
index 2ebb444..65bc83a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,5 @@
 .idea/
 build/
 vendor/
+tests/uploads/
+tests/data/db.sqlite
\ No newline at end of file
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 8ab62f5..73675e2 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -10,7 +10,7 @@
          processIsolation="false"
          stopOnFailure="false">
     <testsuites>
-        <testsuite name="Yii2 Imperavi Test Suite">
+        <testsuite name="Yii2 Attachments test suite">
             <directory>./tests</directory>
         </testsuite>
     </testsuites>
diff --git a/src/Module.php b/src/Module.php
index ef88073..2b73481 100644
--- a/src/Module.php
+++ b/src/Module.php
@@ -4,6 +4,7 @@
 
 use nemmo\attachments\models\File;
 use yii\base\Exception;
+use yii\helpers\ArrayHelper;
 use yii\helpers\FileHelper;
 use yii\i18n\PhpMessageSource;
 
@@ -27,7 +28,7 @@ public function init()
             throw new Exception('Setup {storePath} and {tempPath} in module properties');
         }
 
-        $this->rules = array_replace(['maxFiles' => 3], $this->rules);
+        $this->rules = ArrayHelper::merge(['maxFiles' => 3], $this->rules);
         $this->defaultRoute = 'file';
         $this->registerTranslations();
     }
diff --git a/src/controllers/FileController.php b/src/controllers/FileController.php
index d049a20..39dd6eb 100644
--- a/src/controllers/FileController.php
+++ b/src/controllers/FileController.php
@@ -5,9 +5,11 @@
 use nemmo\attachments\models\File;
 use nemmo\attachments\models\UploadForm;
 use nemmo\attachments\ModuleTrait;
+use Yii;
 use yii\helpers\FileHelper;
 use yii\helpers\Url;
 use yii\web\Controller;
+use yii\web\Response;
 use yii\web\UploadedFile;
 
 class FileController extends Controller
@@ -19,8 +21,8 @@ public function actionUpload()
         $model = new UploadForm();
         $model->file = UploadedFile::getInstances($model, 'file');
 
-        if ($model->rules()[0]['maxFiles'] == 1) {
-            $model->file = UploadedFile::getInstances($model, 'file')[0];
+        if ($model->rules()[0]['maxFiles'] == 1 && sizeof($model->file) == 1) {
+            $model->file = $model->file[0];
         }
 
         if ($model->file && $model->validate()) {
@@ -34,12 +36,15 @@ public function actionUpload()
             } else {
                 $path = $this->getModule()->getUserDirPath() . DIRECTORY_SEPARATOR . $model->file->name;
                 $model->file->saveAs($path);
+                $result['uploadedFiles'][] = $model->file->name;
             }
-            return json_encode($result);
+            Yii::$app->response->format = Response::FORMAT_JSON;
+            return $result;
         } else {
-            return json_encode([
+            Yii::$app->response->format = Response::FORMAT_JSON;
+            return [
                 'error' => $model->getErrors('file')
-            ]);
+            ];
         }
     }
 
@@ -48,14 +53,14 @@ public function actionDownload($id)
         $file = File::findOne(['id' => $id]);
         $filePath = $this->getModule()->getFilesDirPath($file->hash) . DIRECTORY_SEPARATOR . $file->hash . '.' . $file->type;
 
-        return \Yii::$app->response->sendFile($filePath, "$file->name.$file->type");
+        return Yii::$app->response->sendFile($filePath, "$file->name.$file->type");
     }
 
     public function actionDelete($id)
     {
         $this->getModule()->detachFile($id);
 
-        if (\Yii::$app->request->isAjax) {
+        if (Yii::$app->request->isAjax) {
             return json_encode([]);
         } else {
             return $this->redirect(Url::previous());
@@ -66,7 +71,7 @@ public function actionDownloadTemp($filename)
     {
         $filePath = $this->getModule()->getUserDirPath() . DIRECTORY_SEPARATOR . $filename;
 
-        return \Yii::$app->response->sendFile($filePath, $filename);
+        return Yii::$app->response->sendFile($filePath, $filename);
     }
 
     public function actionDeleteTemp($filename)
@@ -78,7 +83,7 @@ public function actionDeleteTemp($filename)
             rmdir($userTempDir);
         }
 
-        if (\Yii::$app->request->isAjax) {
+        if (Yii::$app->request->isAjax) {
             return json_encode([]);
         } else {
             return $this->redirect(Url::previous());
diff --git a/src/models/UploadForm.php b/src/models/UploadForm.php
index 79d5437..64dffcf 100644
--- a/src/models/UploadForm.php
+++ b/src/models/UploadForm.php
@@ -4,6 +4,7 @@
 
 use nemmo\attachments\ModuleTrait;
 use yii\base\Model;
+use yii\helpers\ArrayHelper;
 use yii\web\UploadedFile;
 
 /**
@@ -17,7 +18,7 @@ class UploadForm extends Model
     use ModuleTrait;
 
     /**
-     * @var UploadedFile|Null file attribute
+     * @var UploadedFile[]|UploadedFile file attribute
      */
     public $file;
 
@@ -27,7 +28,7 @@ class UploadForm extends Model
     public function rules()
     {
         return [
-            array_replace([['file'], 'file'], $this->getModule()->rules)
+            ArrayHelper::merge(['file', 'file'], $this->getModule()->rules)
         ];
     }
 }
\ No newline at end of file
diff --git a/tests/FileControllerTest.php b/tests/FileControllerTest.php
new file mode 100644
index 0000000..77b76bb
--- /dev/null
+++ b/tests/FileControllerTest.php
@@ -0,0 +1,117 @@
+<?php
+/**
+ * Created by PhpStorm.
+ * User: Alimzhan
+ * Date: 2/2/2016
+ * Time: 9:45 PM
+ */
+
+namespace tests;
+
+use nemmo\attachments\Module;
+use Yii;
+use yii\helpers\FileHelper;
+use yii\web\UploadedFile;
+
+class FileControllerTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @inheritDoc
+     */
+    protected function setUp()
+    {
+        FileHelper::removeDirectory(Yii::getAlias('@tests/uploads'));
+        UploadedFile::reset();
+    }
+
+    /**
+     * Upload action test
+     */
+    public function testUpload1()
+    {
+        $types = ['png', 'txt', 'jpg'];
+        $this->generateFiles($types);
+        $output = Yii::$app->runAction('attachments/file/upload');
+        $this->assertArrayHasKey('uploadedFiles', $output);
+        $this->assertTrue(in_array('file.png', $output['uploadedFiles']));
+        $this->checkFilesExist($types);
+    }
+
+    public function testUpload2()
+    {
+        $types = ['png', 'txt', 'jpg', 'zip'];
+        $this->generateFiles($types);
+        $output = Yii::$app->runAction('attachments/file/upload');
+        $this->assertArrayHasKey('error', $output);
+    }
+
+    public function testUpload3()
+    {
+        Yii::$app->setModule('attachments', [
+            'class' => Module::className(),
+            'rules' => [
+                'maxFiles' => 1
+            ]
+        ]);
+        $types = ['png', 'zip'];
+        $this->generateFiles($types);
+        $output = Yii::$app->runAction('attachments/file/upload');
+        $this->assertArrayHasKey('error', $output);
+    }
+
+    public function testUpload4()
+    {
+        Yii::$app->setModule('attachments', [
+            'class' => Module::className(),
+            'rules' => [
+                'maxFiles' => 1
+            ]
+        ]);
+        $types = ['png'];
+        $this->generateFiles($types);
+        $output = Yii::$app->runAction('attachments/file/upload');
+        $this->assertArrayHasKey('uploadedFiles', $output);
+        $this->assertTrue(in_array('file.png', $output['uploadedFiles']));
+        $this->checkFilesExist($types);
+    }
+
+    public function testUpload5()
+    {
+        Yii::$app->setModule('attachments', [
+            'class' => Module::className(),
+            'rules' => [
+                'maxFiles' => 3,
+                'mimeTypes' => ['image/png', 'image/jpeg']
+            ]
+        ]);
+        $types = ['png', 'jpg', 'zip'];
+        $this->generateFiles($types);
+        $output = Yii::$app->runAction('attachments/file/upload');
+        var_dump($output);
+        $this->assertArrayHasKey('error', $output);
+    }
+
+    public function generateFiles($types)
+    {
+        $_FILES = [];
+        foreach ($types as $index => $type) {
+            $file = "file.$type";
+            $path = Yii::getAlias("@tests/files/$file");
+            $_FILES["UploadForm[file][$index]"] = [
+                'name' => $file,
+                'type' => mime_content_type($path),
+                'size' => filesize($path),
+                'tmp_name' => $path,
+                'error' => 0
+            ];
+        }
+    }
+
+    public function checkFilesExist($types)
+    {
+        foreach ($types as $type) {
+            $filePath = Yii::getAlias('@tests/uploads/temp/' . Yii::$app->session->id . '/file.' . $type);
+            $this->assertTrue(file_exists($filePath));
+        }
+    }
+}
diff --git a/tests/ModuleTest.php b/tests/ModuleTest.php
index a1214df..6e8047f 100644
--- a/tests/ModuleTest.php
+++ b/tests/ModuleTest.php
@@ -37,7 +37,9 @@ public function testInitException()
 
     public function testInit()
     {
-        Yii::$app->language = 'ru';
+        Yii::$app->setModule('attachments', [
+            'class' => Module::className()
+        ]);
         /** @var Module $module */
         $module = Yii::$app->getModule('attachments');
         $this->assertEquals([
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index fde655e..815dc81 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -6,10 +6,13 @@
  * Time: 9:46 PM
  */
 
-namespace tests;
+namespace yii\web;
 
 use Yii;
 
+/**
+ * Turn on all error reports
+ */
 error_reporting(E_ALL | E_STRICT);
 
 defined('YII_DEBUG') or define('YII_DEBUG', true);
@@ -20,7 +23,9 @@
 
 Yii::setAlias('@tests', __DIR__);
 
-// Overwrite
+/**
+ * Overwrite functions for fake uploads
+ */
 function is_uploaded_file($filename)
 {
     return file_exists($filename);
@@ -31,10 +36,13 @@ function move_uploaded_file($filename, $destination)
     return copy($filename, $destination);
 }
 
+/**
+ * Run yii web application
+ */
 new \yii\web\Application([
     'id' => 'unit',
-    'basePath' => __DIR__,
-    'vendorPath' => __DIR__ . '/../vendor',
+    'basePath' => Yii::getAlias('@tests'),
+    'vendorPath' => Yii::getAlias('@tests/../vendor'),
     'modules' => [
         'attachments' => [
             'class' => \nemmo\attachments\Module::className(),
@@ -48,7 +56,7 @@ function move_uploaded_file($filename, $destination)
         ],
         'db' => [
             'class' => \yii\db\Connection::className(),
-            'dsn' => 'sqlite:' . __DIR__ . '/data/db.sqlite'
+            'dsn' => 'sqlite:' . Yii::getAlias('@tests/data/db.sqlite')
         ]
     ]
 ]);
\ No newline at end of file
diff --git a/tests/files/file.bmp b/tests/files/file.bmp
new file mode 100644
index 0000000..e148d13
Binary files /dev/null and b/tests/files/file.bmp differ
diff --git a/tests/files/file.gif b/tests/files/file.gif
new file mode 100644
index 0000000..c0ad10a
Binary files /dev/null and b/tests/files/file.gif differ
diff --git a/tests/files/file.jpg b/tests/files/file.jpg
new file mode 100644
index 0000000..628ad97
Binary files /dev/null and b/tests/files/file.jpg differ
diff --git a/tests/files/file.mp3 b/tests/files/file.mp3
new file mode 100644
index 0000000..ed6a42a
Binary files /dev/null and b/tests/files/file.mp3 differ
diff --git a/tests/files/yii.png b/tests/files/file.png
similarity index 100%
rename from tests/files/yii.png
rename to tests/files/file.png
diff --git a/tests/files/file.txt b/tests/files/file.txt
new file mode 100644
index 0000000..6c8db5d
--- /dev/null
+++ b/tests/files/file.txt
@@ -0,0 +1 @@
+file 1
\ No newline at end of file
diff --git a/tests/files/file.wav b/tests/files/file.wav
new file mode 100644
index 0000000..f224049
Binary files /dev/null and b/tests/files/file.wav differ
diff --git a/tests/files/file.zip b/tests/files/file.zip
new file mode 100644
index 0000000..693c6ca
Binary files /dev/null and b/tests/files/file.zip differ