MAGETWO-71771: imposible perform full refund for Order Paid with PayPal Payments Standard

-Add integration test for Nvp::callRefundTransaction

Author: danielrenaud

dev/tests/integration/testsuite/Magento/Paypal/Model/Api/NvpTest.php

@@ -118,6 +118,49 @@ public function testRequestTotalsAndLineItemsWithFPT()
         $this->nvpApi->callSetExpressCheckout();
     }
 
+    /**
+     * Test that the refund request to Paypal sends the correct data
+     *
+     * @magentoDataFixture Magento/Paypal/_files/order_standard_with_tax_and_invoice.php
+     */
+    public function testCallRefundTransaction()
+    {
+        $this->assertTrue(true);
+        /** @var \Magento\Sales\Model\Order $order */
+        $order = $this->objectManager->create(\Magento\Sales\Model\Order::class);
+        $order->loadByIncrementId('100000001');
+
+        /** @var \Magento\Sales\Model\Order\Payment $payment */
+        $payment = $order->getPayment();
+
+        $this->nvpApi->setPayment(
+            $payment
+        )->setTransactionId(
+            'fooTransactionId'
+        )->setAmount(
+            $payment->formatAmount($order->getBaseGrandTotal())
+        )->setCurrencyCode(
+            $order->getBaseCurrencyCode()
+        )->setRefundType(
+            Config::REFUND_TYPE_PARTIAL
+        );
+
+        $httpQuery = 'TRANSACTIONID=fooTransactionId&REFUNDTYPE=Partial'
+            .'&CURRENCYCODE=USD&AMT=145.98&METHOD=RefundTransaction'
+            .'&VERSION=72.0&BUTTONSOURCE=Magento_Cart_';
+
+        $this->httpClient->expects($this->once())->method('write')
+            ->with(
+                'POST',
+                'https://api-3t.paypal.com/nvp',
+                '1.1',
+                [],
+                $httpQuery
+            );
+
+        $this->nvpApi->callRefundTransaction();
+    }
+
     /**
      * Gets quote by reserved order id.
      *

dev/tests/integration/testsuite/Magento/Paypal/_files/order_standard_with_tax_and_invoice.php

@@ -0,0 +1,93 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+use Magento\Framework\DB\Transaction;
+use Magento\Paypal\Model\Config;
+use Magento\Sales\Api\InvoiceManagementInterface;
+use Magento\Sales\Api\OrderRepositoryInterface;
+use Magento\Sales\Model\Order;
+use Magento\Sales\Model\Order\Item;
+use Magento\Sales\Model\Order\Address;
+use Magento\Sales\Model\Order\Payment;
+use Magento\Sales\Model\Service\InvoiceService;
+use Magento\TestFramework\Helper\Bootstrap;
+
+require __DIR__ . '/../../../Magento/Catalog/_files/product_simple.php';
+$product->setPrice(121);
+
+$objectManager = Bootstrap::getObjectManager();
+
+$addressData = include __DIR__ . '/address_data.php';
+$billingAddress = $objectManager->create(
+    Address::class,
+    ['data' => $addressData]
+);
+$billingAddress->setAddressType('billing');
+$shippingAddress = clone $billingAddress;
+$shippingAddress->setId(null)->setAddressType('shipping');
+
+$payment = $objectManager->create(Payment::class);
+$payment->setMethod(Config::METHOD_WPS_EXPRESS);
+
+$taxRate = .0825;
+$taxAmount = $product->getPrice() * $taxRate;
+
+/** @var Item $orderItem */
+$orderItem = $objectManager->create(Item::class);
+$orderItem->setProductId($product->getId())->setQtyOrdered(1);
+$orderItem->setBasePrice($product->getPrice());
+$orderItem->setPrice($product->getPrice());
+$orderItem->setRowTotal($product->getPrice());
+$orderItem->setRowTotalInclTax($product->getPrice() + $taxAmount);
+$orderItem->setBaseRowTotal($product->getPrice());
+$orderItem->setBaseRowTotalInclTax($product->getPrice() + $taxAmount);
+$orderItem->setBaseRowInvoiced($product->getPrice()  + $taxAmount);
+$orderItem->setProductType('simple');
+
+$itemsAmount = $product->getPrice();
+$shippingAmount = 15;
+$itemsAmountInclTax = $itemsAmount + $taxAmount;
+$totalAmount = $itemsAmountInclTax + $shippingAmount;
+
+/** @var Order $order */
+$order = $objectManager->create(Order::class);
+$order->setCustomerEmail('[email protected]')
+    ->setIncrementId('100000001')
+    ->addItem($orderItem)
+    ->setSubtotal($itemsAmount)
+    ->setBaseSubtotal($itemsAmount)
+    ->setBaseGrandTotal($totalAmount)
+    ->setGrandTotal($totalAmount)
+    ->setTaxAmount($taxAmount)
+    ->setBaseCurrencyCode('USD')
+    ->setCustomerIsGuest(true)
+    ->setStoreId(1)
+    ->setEmailSent(true)
+    ->setState(Order::STATE_PROCESSING)
+    ->setBillingAddress($billingAddress)
+    ->setShippingAddress($shippingAddress)
+    ->setBaseTotalPaid($totalAmount)
+    ->setTotalPaid($totalAmount)
+    ->setData('base_to_global_rate', 1)
+    ->setData('base_to_order_rate', 1)
+    ->setData('shipping_amount', $shippingAmount)
+    ->setData('base_shipping_amount', $shippingAmount)
+    ->setPayment($payment);
+
+/** @var OrderRepositoryInterface $orderRepository */
+$orderRepository = $objectManager->get(OrderRepositoryInterface::class);
+$orderRepository->save($order);
+
+/** @var InvoiceService $invoiceService */
+$invoiceService = $objectManager->create(InvoiceManagementInterface::class);
+
+/** @var Transaction $transaction */
+$transaction = $objectManager->create(Transaction::class);
+
+$invoice = $invoiceService->prepareInvoice($order, [$orderItem->getId() => 1]);
+$invoice->register();
+
+$transaction->addObject($invoice)->addObject($order)->save();