magento-engcom/import-export-improvements#43: add a fallback for when older code with a customer object is used

 - in the addCustomer covert $customerData['id'] to $customerData['entity_id'] so that older code that uses customer objects will still work as expected

Author: dmanners

app/code/Magento/CustomerImportExport/Model/ResourceModel/Import/Customer/Storage.php

@@ -112,7 +112,11 @@ public function addCustomerByArray(array $customer)
      */
     public function addCustomer(\Magento\Framework\DataObject $customer)
     {
-        $this->addCustomerByArray($customer->toArray());
+        $customerData = $customer->toArray();
+        if (!isset($customerData['entity_id']) && isset($customer['id'])) {
+            $customerData['entity_id'] = $customerData['id'];
+        }
+        $this->addCustomerByArray($customerData);
 
         return $this;
     }

app/code/Magento/CustomerImportExport/Test/Unit/Model/ResourceModel/Import/Customer/StorageTest.php

@@ -101,6 +101,20 @@ public function testLoad()
     }
 
     public function testAddCustomer()
+    {
+        $customer = new \Magento\Framework\DataObject(['id' => 1, 'website_id' => 1, 'email' => 'test@test.com']);
+        $this->_model->addCustomer($customer);
+
+        $propertyName = '_customerIds';
+        $this->assertAttributeCount(1, $propertyName, $this->_model);
+        $this->assertAttributeContains([$customer->getWebsiteId() => $customer->getId()], $propertyName, $this->_model);
+        $this->assertEquals(
+            $customer->getId(),
+            $this->_model->getCustomerId($customer->getEmail(), $customer->getWebsiteId())
+        );
+    }
+
+    public function testAddCustomerByArray()
     {
         $propertyName = '_customerIds';
         $customer = $this->_addCustomerToStorage();