diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..3809b37
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,35 @@
+# phpstorm project files
+.idea
+
+# netbeans project files
+nbproject
+
+# zend studio for eclipse project files
+.buildpath
+.project
+.settings
+
+# windows thumbnail cache
+Thumbs.db
+
+# composer vendor dir
+/vendor
+
+/composer.lock
+
+# composer itself is not needed
+composer.phar
+
+# Mac DS_Store Files
+.DS_Store
+
+# phpunit itself is not needed
+phpunit.phar
+# local phpunit config
+/phpunit.xml
+
+# local tests configuration
+/tests/data/config.local.php
+
+# runtime cache
+/tests/runtime
diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..07dc6e4
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,31 @@
+language: php
+
+php:
+  - 5.5
+  - 5.6
+  - 7.0
+  - 7.1
+  - 7.2
+
+sudo: true
+
+# cache vendor dirs
+cache:
+  directories:
+    - $HOME/.composer/cache
+
+install:
+  - travis_retry composer self-update && composer --version
+  - export PATH="$HOME/.composer/vendor/bin:$PATH"
+  - travis_retry composer install --prefer-dist --no-interaction
+
+script:
+  - phpunit --verbose $PHPUNIT_FLAGS
+
+after_script:
+  - |
+    if [ $TRAVIS_PHP_VERSION = '5.6' ]; then
+      cd ../../..
+      travis_retry wget https://scrutinizer-ci.com/ocular.phar
+      php ocular.phar code-coverage:upload --format=php-clover coverage.clover
+    fi
diff --git a/Merchant.php b/Merchant.php
index 03f1f2f..0ab8523 100644
--- a/Merchant.php
+++ b/Merchant.php
@@ -3,9 +3,9 @@
 namespace robokassa;
 
 use Yii;
-use yii\base\Object;
+use yii\base\BaseObject;
 
-class Merchant extends Object
+class Merchant extends BaseObject
 {
     public $sMerchantLogin;
 
@@ -23,9 +23,11 @@ public function payment($nOutSum, $nInvId, $sInvDesc = null, $sIncCurrLabel=null
         $url = $this->baseUrl;
 
         $signature = "{$this->sMerchantLogin}:{$nOutSum}:{$nInvId}:{$this->sMerchantPass1}";
+
         if (!empty($shp)) {
             $signature .= ':' . $this->implodeShp($shp);
         }
+
         $sSignatureValue = $this->encryptSignature($signature);
 
         $url .= '?' . http_build_query([
@@ -37,7 +39,7 @@ public function payment($nOutSum, $nInvId, $sInvDesc = null, $sIncCurrLabel=null
             'IncCurrLabel' => $sIncCurrLabel,
             'Email' => $sEmail,
             'Culture' => $sCulture,
-            'IsTest' => (int)$this->isTest,
+            'IsTest' => $this->isTest ? 1 : null,
         ]);
 
         if (!empty($shp) && ($query = http_build_query($shp)) !== '') {
@@ -55,6 +57,7 @@ public function payment($nOutSum, $nInvId, $sInvDesc = null, $sIncCurrLabel=null
     private function implodeShp($shp)
     {
         ksort($shp);
+
         foreach($shp as $key => $value) {
             $shp[$key] = $key . '=' . $value;
         }
@@ -62,17 +65,19 @@ private function implodeShp($shp)
         return implode(':', $shp);
     }
 
-    public  function checkSignature($sSignatureValue, $nOutSum, $nInvId, $sMerchantPass, $shp)
+    public function checkSignature($sSignatureValue, $nOutSum, $nInvId, $sMerchantPass, $shp = [])
     {
         $signature = "{$nOutSum}:{$nInvId}:{$sMerchantPass}";
+
         if (!empty($shp)) {
             $signature .= ':' . $this->implodeShp($shp);
         }
+
         return strtolower($this->encryptSignature($signature)) === strtolower($sSignatureValue);
 
     }
     
-    private function encryptSignature($signature)
+    protected function encryptSignature($signature)
     {
         return hash($this->hashAlgo, $signature);
     }
diff --git a/README.md b/README.md
index fac34de..0079214 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,11 @@
 yii2-robokassa
 ==============
 
+[![Latest Stable Version](https://poser.pugx.org/yii-cms/yii2-robokassa/v/stable.png)](https://packagist.org/packages/yii-cms/yii2-robokassa)
+[![Total Downloads](https://poser.pugx.org/yii-cms/yii2-robokassa/downloads.png)](https://packagist.org/packages/yii-cms/yii2-robokassa)
+[![Build Status](https://travis-ci.org/yii-cms/yii2-robokassa.svg?branch=master)](https://travis-ci.org/yii-cms/yii2-robokassa)
+
+
 ## Install via Composer
 
 ~~~
diff --git a/composer.json b/composer.json
index c3d4acb..1fc1dfc 100644
--- a/composer.json
+++ b/composer.json
@@ -12,10 +12,20 @@
     ],
     "minimum-stability": "dev",
     "require": {
-        "php": ">=5.4.0",
-        "yiisoft/yii2": "*"
+        "yiisoft/yii2": "~2.0.13"
     },
+    "repositories": [
+        {
+            "type": "composer",
+            "url": "https://asset-packagist.org"
+        }
+    ],
     "autoload": {
         "psr-4": { "robokassa\\": "" }
+    },
+    "extra": {
+        "branch-alias": {
+            "dev-master": "1.2.x-dev"
+        }
     }
 }
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
new file mode 100644
index 0000000..346708d
--- /dev/null
+++ b/phpunit.xml.dist
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<phpunit bootstrap="./tests/bootstrap.php"
+         colors="true"
+         convertErrorsToExceptions="true"
+         convertNoticesToExceptions="true"
+         convertWarningsToExceptions="true"
+         stopOnFailure="false">
+    <testsuites>
+        <testsuite name="Yii2 Robokassa Test Suite">
+            <directory>./tests/unit</directory>
+        </testsuite>
+    </testsuites>
+    <filter>
+        <whitelist processUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">.</directory>
+            <exclude>
+                <directory suffix=".php">vendor</directory>
+            </exclude>
+        </whitelist>
+    </filter>
+</phpunit>
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
new file mode 100644
index 0000000..ef5fb8e
--- /dev/null
+++ b/tests/bootstrap.php
@@ -0,0 +1,17 @@
+<?php
+
+error_reporting(E_ALL);
+
+define('YII_ENABLE_ERROR_HANDLER', false);
+define('YII_DEBUG', true);
+
+$_SERVER['SCRIPT_NAME'] = '/' . __DIR__;
+$_SERVER['SCRIPT_FILENAME'] = __FILE__;
+
+require_once(__DIR__ . '/../vendor/autoload.php');
+require_once(__DIR__ . '/../vendor/yiisoft/yii2/Yii.php');
+
+Yii::setAlias('@robokassa/tests/unit', __DIR__ . '/unit');
+Yii::setAlias('@robokassa', dirname(__DIR__));
+
+require_once(__DIR__ . '/compatibility.php');
diff --git a/tests/compatibility.php b/tests/compatibility.php
new file mode 100644
index 0000000..e5e857e
--- /dev/null
+++ b/tests/compatibility.php
@@ -0,0 +1,51 @@
+<?php
+
+/*
+ * Ensures compatibility with PHPUnit < 6.x
+ */
+namespace PHPUnit\Framework\Constraint {
+    if (!class_exists('PHPUnit\Framework\Constraint\Constraint') && class_exists('PHPUnit_Framework_Constraint')) {
+        abstract class Constraint extends \PHPUnit_Framework_Constraint {}
+    }
+}
+
+namespace PHPUnit\Framework {
+    if (!class_exists('PHPUnit\Framework\TestCase') && class_exists('PHPUnit_Framework_TestCase')) {
+        abstract class TestCase extends \PHPUnit_Framework_TestCase
+        {
+            /**
+             * @param string $exception
+             */
+            public function expectException($exception)
+            {
+                $this->setExpectedException($exception);
+            }
+
+            /**
+             * @param string $message
+             */
+            public function expectExceptionMessage($message)
+            {
+                $parentClassMethods = get_class_methods('PHPUnit_Framework_TestCase');
+                if (in_array('expectExceptionMessage', $parentClassMethods)) {
+                    parent::expectExceptionMessage($message);
+                    return;
+                }
+                $this->setExpectedException($this->getExpectedException(), $message);
+            }
+
+            /**
+             * @param string $messageRegExp
+             */
+            public function expectExceptionMessageRegExp($messageRegExp)
+            {
+                $parentClassMethods = get_class_methods('PHPUnit_Framework_TestCase');
+                if (in_array('expectExceptionMessageRegExp', $parentClassMethods)) {
+                    parent::expectExceptionMessageRegExp($messageRegExp);
+                    return;
+                }
+                $this->setExpectedExceptionRegExp($this->getExpectedException(), $messageRegExp);
+            }
+        }
+    }
+}
diff --git a/tests/unit/MerchantTest.php b/tests/unit/MerchantTest.php
new file mode 100644
index 0000000..2667f4d
--- /dev/null
+++ b/tests/unit/MerchantTest.php
@@ -0,0 +1,94 @@
+<?php
+namespace robokassa\tests\unit;
+
+use robokassa\Merchant;
+
+class MerchantTest extends TestCase
+{
+    public function testRedirectUrl()
+    {
+        $merchant = new Merchant([
+            'sMerchantLogin' => 'demo',
+            'sMerchantPass1' => 'password_1',
+            'hashAlgo' => 'md5',
+            'isTest' => true,
+        ]);
+
+        $returnUrl = $merchant->payment(100, 1, 'Description', null, null, 'en', [], true);
+
+        $this->assertEquals("https://auth.robokassa.ru/Merchant/Index.aspx?MrchLogin=demo&OutSum=100&InvId=1&Desc=Description&SignatureValue=8a50b8d86ed28921edfc371cff6e156f&Culture=en&IsTest=1", $returnUrl);
+
+        // disable test
+        $merchant->isTest = false;
+
+        $returnUrl = $merchant->payment(100, 1, 'Description', null, null, 'en', [], true);
+
+        $this->assertEquals("https://auth.robokassa.ru/Merchant/Index.aspx?MrchLogin=demo&OutSum=100&InvId=1&Desc=Description&SignatureValue=8a50b8d86ed28921edfc371cff6e156f&Culture=en", $returnUrl);
+    }
+
+    public function testSignature()
+    {
+        $merchant = new Merchant([
+            'sMerchantLogin' => 'demo',
+            'sMerchantPass1' => 'password_1',
+            'hashAlgo' => 'md5',
+            'isTest' => true,
+        ]);
+
+        $signature = md5('100:1:pass1'); // '1e8f0be69238c13020beba0206951535'
+
+        $check = $merchant->checkSignature($signature, 100, 1, 'pass1');
+
+        $this->assertInternalType('boolean', $check);
+
+        $this->assertTrue($check);
+    }
+
+    public function testSignatureUserParams()
+    {
+        $merchant = new Merchant([
+            'sMerchantLogin' => 'demo',
+            'sMerchantPass1' => 'password_1',
+            'hashAlgo' => 'md5',
+            'isTest' => true,
+        ]);
+
+        $signature = md5('100:1:pass1:shp_id=1:shp_login=user1'); // 'd2b1beae30b0c2586eb4b4a7ce23aedd'
+
+        $this->assertTrue($merchant->checkSignature($signature, 100, 1, 'pass1', [
+            'shp_id' => 1,
+            'shp_login' => 'user1',
+        ]));
+    }
+
+    public function testSignatureInvalidSortUserParams()
+    {
+        $merchant = new Merchant([
+            'sMerchantLogin' => 'demo',
+            'sMerchantPass1' => 'password_1',
+            'hashAlgo' => 'md5',
+            'isTest' => true,
+        ]);
+
+        $signatureInvalidSort = md5('100:1:pass1:shp_login=user1:shp_id=1');
+
+        $this->assertFalse($merchant->checkSignature($signatureInvalidSort, 100, 1, 'pass1', [
+            'shp_id' => 1,
+            'shp_login' => 'user1',
+        ]));
+    }
+
+    public function testSignatureAlgo()
+    {
+        $merchant = new Merchant([
+            'sMerchantLogin' => 'demo',
+            'sMerchantPass1' => 'password_1',
+            'hashAlgo' => 'sha256', // <=== 'sha256'
+            'isTest' => true,
+        ]);
+
+        $signature = hash('sha256', '100:1:pass1');
+
+        $this->assertTrue($merchant->checkSignature($signature, 100, 1, 'pass1'));
+    }
+}
diff --git a/tests/unit/TestCase.php b/tests/unit/TestCase.php
new file mode 100644
index 0000000..da30f0d
--- /dev/null
+++ b/tests/unit/TestCase.php
@@ -0,0 +1,79 @@
+<?php
+namespace robokassa\tests\unit;
+
+use yii\di\Container;
+use yii\helpers\ArrayHelper;
+use Yii;
+
+/**
+ * Base class for the test cases.
+ */
+class TestCase extends \PHPUnit\Framework\TestCase
+{
+    protected function setUp()
+    {
+        parent::setUp();
+        $this->mockApplication();
+    }
+
+    protected function tearDown()
+    {
+        $this->destroyApplication();
+    }
+
+    /**
+     * Populates Yii::$app with a new application
+     * The application will be destroyed on tearDown() automatically.
+     * @param array $config The application configuration, if needed
+     * @param string $appClass name of the application class to create
+     */
+    protected function mockApplication($config = [], $appClass = '\yii\console\Application')
+    {
+        new $appClass(ArrayHelper::merge([
+            'id' => 'testapp',
+            'basePath' => __DIR__,
+            'vendorPath' => $this->getVendorPath(),
+        ], $config));
+    }
+
+    protected function mockWebApplication($config = [], $appClass = '\yii\web\Application')
+    {
+        new $appClass(ArrayHelper::merge([
+            'id' => 'testapp',
+            'basePath' => __DIR__,
+            'vendorPath' => dirname(__DIR__) . '/vendor',
+            'components' => [
+                'request' => [
+                    'cookieValidationKey' => 'test',
+                    'scriptFile' => __DIR__ .'/index.php',
+                    'scriptUrl' => '/index.php',
+                ],
+                'robokassa' => [
+                    'class' => '\robokassa\Merchant',
+                    'baseUrl' => 'https://auth.robokassa.ru/Merchant/Index.aspx',
+                    'sMerchantLogin' => 'demo',
+                    'sMerchantPass1' => 'test1TEST',
+                    'sMerchantPass2' => 'test2TEST',
+                    'isTest' => true,
+                ],
+            ]
+        ], $config));
+    }
+
+    /**
+     * @return string vendor path
+     */
+    protected function getVendorPath()
+    {
+        return dirname(dirname(__DIR__)) . '/vendor';
+    }
+
+    /**
+     * Destroys application in Yii::$app by setting it to null.
+     */
+    protected function destroyApplication()
+    {
+        Yii::$app = null;
+        Yii::$container = new Container();
+    }
+}