Initial unit tests setup

.github/PULL_REQUEST_TEMPLATE.md

+<!-- Thank you for considering contributing to this repository! We encourage you to use PSR-2. -->
+
 **Description**
 <!-- Please provide a description of the changes proposed in the Pull Request -->
 
 **Tested scenarios**
 <!-- Description of tested scenarios -->
+<!-- Please verify that the unit tests are passing by running "vendor/bin/phpunit -c ." -->
 
 **Fixed issue**:  <!-- #-prefixed issue number -->
\ No newline at end of file

composer.json

@@ -7,8 +7,18 @@
     "OSL-3.0",
     "AFL-3.0"
   ],
+  "repositories": [
+    {
+      "type": "composer",
+      "url": "https://repo.magento.com/"
+    }
+  ],
   "require": {
-    "adyen/php-api-library": "*"
+    "adyen/php-api-library": "*",
+    "magento/framework": ">=100.1.0"
+  },
+  "require-dev": {
+    "phpunit/phpunit": "~5"
   },
   "autoload": {
     "files": [
@@ -17,5 +27,10 @@
     "psr-4": {
       "Adyen\\Payment\\": ""
     }
+  },
+  "autoload-dev": {
+    "psr-4": {
+      "Adyen\\Payment\\Tests\\": "tests/"
+    }
   }
 }

phpunit.xml

+<phpunit bootstrap="vendor/autoload.php">
+    <testsuites>
+        <testsuite name="Adyen payment module tests">
+            <directory>tests</directory>
+        </testsuite>
+    </testsuites>
+</phpunit>

tests/Helper/DataTest.php

+<?php
+/**
+ *                       ######
+ *                       ######
+ * ############    ####( ######  #####. ######  ############   ############
+ * #############  #####( ######  #####. ######  #############  #############
+ *        ######  #####( ######  #####. ######  #####  ######  #####  ######
+ * ###### ######  #####( ######  #####. ######  #####  #####   #####  ######
+ * ###### ######  #####( ######  #####. ######  #####          #####  ######
+ * #############  #############  #############  #############  #####  ######
+ *  ############   ############  #############   ############  #####  ######
+ *                                      ######
+ *                               #############
+ *                               ############
+ *
+ * Adyen Payment module (https://www.adyen.com/)
+ *
+ * Copyright (c) 2015 Adyen BV (https://www.adyen.com/)
+ * See LICENSE.txt for license details.
+ *
+ * Author: Adyen <magento@adyen.com>
+ */
+
+namespace Adyen\Payment\Tests\Helper;
+
+use Adyen\Payment\Helper\Data;
+use PHPUnit\Framework\TestCase;
+
+class DataTest extends TestCase
+{
+    private $dataHelper;
+
+    private function getSimpleMock($originalClassName)
+    {
+        return $this->getMockBuilder($originalClassName)
+            ->disableOriginalConstructor()
+            ->getMock();
+    }
+
+    public function setUp()
+    {
+        $context = $this->getSimpleMock('\Magento\Framework\App\Helper\Context');
+        $encryptor = $this->getSimpleMock('\Magento\Framework\Encryption\EncryptorInterface');
+        $dataStorage = $this->getSimpleMock('\Magento\Framework\Config\DataInterface');
+        $country = $this->getSimpleMock('\Magento\Directory\Model\Config\Source\Country');
+        $moduleList = $this->getSimpleMock('\Magento\Framework\Module\ModuleListInterface');
+        $billingAgreementCollectionFactory = $this->getSimpleMock('\Adyen\Payment\Model\Resource\Billing\Agreement\CollectionFactory');
+        $assetRepo = $this->getSimpleMock('\Magento\Framework\View\Asset\Repository');
+        $assetSource = $this->getSimpleMock('\Magento\Framework\View\Asset\Source');
+        $notificationFactory = $this->getSimpleMock('\Adyen\Payment\Model\Resource\Notification\CollectionFactory');
+
+        $this->dataHelper = new Data($context, $encryptor, $dataStorage, $country, $moduleList,
+            $billingAgreementCollectionFactory, $assetRepo, $assetSource, $notificationFactory);
+    }
+
+    public function testFormatAmount()
+    {
+        $this->assertEquals("1234", $this->dataHelper->formatAmount("12.34", "EUR"));
+        $this->assertEquals("1200", $this->dataHelper->formatAmount("12.00", "USD"));
+        $this->assertEquals("12", $this->dataHelper->formatAmount("12.00", "JPY"));
+    }
+}