MAGETWO-71831: Unable to create a shipping label for a shipment with USPS

- Add formatting decimal values according USPS API

Author: viktym

app/code/Magento/Usps/Model/Carrier.php

@@ -1795,10 +1795,10 @@ protected function _formIntlShipmentRequest(\Magento\Framework\DataObject $reque
             }
             $individualItemWeight = $itemWeight / $ceiledQty;
             $itemDetail->addChild('Quantity', $ceiledQty);
-            $itemDetail->addChild('Value', $item->getCustomsValue() * $item->getQty());
+            $itemDetail->addChild('Value', sprintf('%.2F', $item->getCustomsValue() * $item->getQty()));
             list($individualPoundsWeight, $individualOuncesWeight) = $this->_convertPoundOunces($individualItemWeight);
             $itemDetail->addChild('NetPounds', $individualPoundsWeight);
-            $itemDetail->addChild('NetOunces', $individualOuncesWeight);
+            $itemDetail->addChild('NetOunces', sprintf('%.2F', $individualOuncesWeight));
             $itemDetail->addChild('HSTariffNumber', 0);
             $itemDetail->addChild('CountryOfOrigin', $countryOfManufacture);
 
@@ -1814,7 +1814,7 @@ protected function _formIntlShipmentRequest(\Magento\Framework\DataObject $reque
         }
 
         $xml->addChild('GrossPounds', $packagePoundsWeight);
-        $xml->addChild('GrossOunces', $packageOuncesWeight);
+        $xml->addChild('GrossOunces', sprintf('%.2F', $packageOuncesWeight));
         if ($packageParams->getContentType() == 'OTHER' && $packageParams->getContentTypeOther() != null) {
             $xml->addChild('ContentType', $packageParams->getContentType());
             $xml->addChild('ContentTypeOther ', $packageParams->getContentTypeOther());

app/code/Magento/Usps/Test/Unit/Model/CarrierTest.php

@@ -5,6 +5,7 @@
  */
 namespace Magento\Usps\Test\Unit\Model;
 
+use Magento\Catalog\Model\ResourceModel\Product\CollectionFactory;
 use Magento\Framework\HTTP\ZendClient;
 use Magento\Framework\HTTP\ZendClientFactory;
 use Magento\Quote\Model\Quote\Address\RateRequest;
@@ -162,6 +163,22 @@ function ($data) {
             ]
         );
 
+        $productCollection = $this->getMockBuilder(\Magento\Catalog\Model\ResourceModel\Product\Collection::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $productCollection->method('addStoreFilter')
+            ->willReturnSelf();
+        $productCollection->method('addFieldToFilter')
+            ->willReturnSelf();
+        $productCollection->method('addAttributeToSelect')
+            ->willReturn([]);
+
+        $productCollectionFactory = $this->getMockBuilder(CollectionFactory::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $productCollectionFactory->method('create')
+            ->willReturn($productCollection);
+
         $arguments = [
             'scopeConfig' => $this->scope,
             'xmlSecurity' => new \Magento\Framework\Xml\Security(),
@@ -172,6 +189,7 @@ function ($data) {
             'data' => $data,
             'rateErrorFactory' => $this->errorFactory,
             'carrierHelper' => $carrierHelper,
+            'productCollectionFactory' => $productCollectionFactory,
         ];
 
         $this->dataHelper = $this->getMockBuilder(DataHelper::class)
@@ -265,6 +283,32 @@ public function testReturnOfShipment()
         $this->assertNotEmpty($this->carrier->returnOfShipment($request)->getInfo()[0]['tracking_number']);
     }
 
+    public function testFormattingFloatValuesForIntlShipmentRequest()
+    {
+        $this->httpResponse->method('getBody')
+            ->willReturn(
+                file_get_contents(__DIR__ . '/_files/success_usps_response_return_shipment.xml')
+            );
+        $request = $this->objectManager->getObject(
+            \Magento\Shipping\Model\Shipment\ReturnShipment::class,
+            require __DIR__ . '/_files/return_shipment_request_data.php'
+        );
+
+        $request->setRecipientAddressCountryCode('UK');
+        $formattedValuesRegex = '(<Value>5.00<\/Value>).*';
+        $formattedValuesRegex .= '(<NetOunces>0.00<\/NetOunces>).*';
+        $formattedValuesRegex .= '(<GrossOunces>0.00<\/GrossOunces>)';
+
+        $this->httpClient->expects($this->exactly(2))
+            ->method('setParameterGet')
+            ->withConsecutive(
+                ['API', 'ExpressMailIntl'],
+                ['XML', $this->matchesRegularExpression('/' . $formattedValuesRegex . '/')]
+            );
+
+        $this->carrier->returnOfShipment($request);
+    }
+
     /**
      * Emulates the config's `getValue` method.
      *