Correctly set payment information when using paypal

Author: therool

app/code/Magento/Paypal/Model/Express.php

@@ -669,14 +669,19 @@ public function getApi()
     public function assignData(\Magento\Framework\DataObject $data)
     {
         parent::assignData($data);
-        
+
         $additionalData = $data->getData(PaymentInterface::KEY_ADDITIONAL_DATA);
 
         if (!is_array($additionalData)) {
             return $this;
         }
 
         foreach ($additionalData as $key => $value) {
+            // Skip extension attributes
+            if ($key === \Magento\Framework\Api\ExtensibleDataInterface::EXTENSION_ATTRIBUTES_KEY) {
+                continue;
+            }
+
             $this->getInfoInstance()->setAdditionalInformation($key, $value);
         }
         return $this;

app/code/Magento/Paypal/Test/Unit/Model/ExpressTest.php

@@ -161,12 +161,21 @@ public function testAssignData()
     {
         $transportValue = 'something';
 
+        $extensionAttributeMock = $this->getMockForAbstractClass(
+            \Magento\Quote\Api\Data\PaymentExtensionInterface::class,
+            [],
+            '',
+            false,
+            false
+        );
+
         $data = new DataObject(
             [
                 PaymentInterface::KEY_ADDITIONAL_DATA => [
                     Express\Checkout::PAYMENT_INFO_TRANSPORT_BILLING_AGREEMENT => $transportValue,
                     Express\Checkout::PAYMENT_INFO_TRANSPORT_PAYER_ID => $transportValue,
-                    Express\Checkout::PAYMENT_INFO_TRANSPORT_TOKEN => $transportValue
+                    Express\Checkout::PAYMENT_INFO_TRANSPORT_TOKEN => $transportValue,
+                    \Magento\Framework\Api\ExtensibleDataInterface::EXTENSION_ATTRIBUTES_KEY => $extensionAttributeMock
                 ]
             ]
         );

app/code/Magento/Paypal/view/frontend/web/js/action/set-payment-method.js

@@ -10,42 +10,12 @@ define([
     'mage/storage',
     'Magento_Checkout/js/model/error-processor',
     'Magento_Customer/js/model/customer',
-    'Magento_Checkout/js/model/full-screen-loader'
-], function ($, quote, urlBuilder, storage, errorProcessor, customer, fullScreenLoader) {
+    'Magento_Checkout/js/model/full-screen-loader',
+    'Magento_Checkout/js/action/set-payment-information'
+], function ($, quote, urlBuilder, storage, errorProcessor, customer, fullScreenLoader, setPaymentInformation) {
     'use strict';
 
     return function (messageContainer) {
-        var serviceUrl,
-            payload,
-            paymentData = quote.paymentMethod();
-
-        /**
-         * Checkout for guest and registered customer.
-         */
-        if (!customer.isLoggedIn()) {
-            serviceUrl = urlBuilder.createUrl('/guest-carts/:cartId/set-payment-information', {
-                cartId: quote.getQuoteId()
-            });
-            payload = {
-                cartId: quote.getQuoteId(),
-                email: quote.guestEmail,
-                paymentMethod: paymentData
-            };
-        } else {
-            serviceUrl = urlBuilder.createUrl('/carts/mine/set-payment-information', {});
-            payload = {
-                cartId: quote.getQuoteId(),
-                paymentMethod: paymentData
-            };
-        }
-        fullScreenLoader.startLoader();
-
-        return storage.post(
-            serviceUrl, JSON.stringify(payload)
-        ).fail(function (response) {
-            errorProcessor.process(response, messageContainer);
-        }).always(function () {
-            fullScreenLoader.stopLoader();
-        });
+        return setPaymentInformation(messageContainer, quote.paymentMethod());
     };
-});
+});