MAGETWO-77969: [2.1.x] - Unable to place order on environment with split database within PayPal Express Checkout

Author: OlgaVasyltsun

app/code/Magento/Sales/Model/OrderIncrementIdChecker.php

@@ -7,7 +7,7 @@
 namespace Magento\Sales\Model;
 
 /**
- * This class uses for checking if reserved order id was already used for some order
+ * This class uses for checking if reserved order id was already used for some order.
  */
 class OrderIncrementIdChecker
 {

app/code/Magento/Sales/Test/Unit/Model/OrderIncrementIdCheckerTest.php

@@ -6,6 +6,9 @@
 
 namespace Magento\Sales\Test\Unit\Model;
 
+/**
+ * Tests \Magento\Sales\Model\OrderIncrementIdChecker.
+ */
 class OrderIncrementIdCheckerTest extends \PHPUnit_Framework_TestCase
 {
     /**
@@ -59,13 +62,13 @@ protected function setUp()
         $this->model = $objectManagerHelper->getObject(
             \Magento\Sales\Model\OrderIncrementIdChecker::class,
             [
-                'resourceModel' => $this->resourceMock
+                'resourceModel' => $this->resourceMock,
             ]
         );
     }
 
     /**
-     * Unit test to verify if isOrderIncrementIdUsed method works with different types increment ids
+     * Unit test to verify if isOrderIncrementIdUsed method works with different types increment ids.
      *
      * @param array $value
      * @return void

dev/tests/integration/testsuite/Magento/Sales/Model/OrderIncrementIdCheckerTest.php

@@ -7,7 +7,7 @@
 namespace Magento\Sales\Model;
 
 /**
- * Class QuoteTest to verify isOrderIncrementIdUsed method behaviour
+ * Class OrderIncrementIdCheckerTest to verify isIncrementIdUsed method behaviour.
  */
 class OrderIncrementIdCheckerTest extends \PHPUnit_Framework_TestCase
 {
@@ -27,23 +27,23 @@ protected function setUp()
     }
 
     /**
-     * Test to verify if isOrderIncrementIdUsed method works with numeric increment ids
+     * Test to verify if isIncrementIdUsed method works with numeric increment ids.
      *
      * @magentoDataFixture Magento/Sales/_files/order.php
      * @return void
      */
-    public function testIsOrderIncrementIdUsedNumericIncrementId()
+    public function testIsIncrementIdUsedNumericIncrementId()
     {
         $this->assertTrue($this->checker->isIncrementIdUsed('100000001'));
     }
 
     /**
-     * Test to verify if isOrderIncrementIdUsed method works with alphanumeric increment ids
+     * Test to verify if IsIncrementIdUsed method works with alphanumeric increment ids.
      *
      * @magentoDataFixture Magento/Sales/_files/order_alphanumeric_id.php
      * @return void
      */
-    public function testIsOrderIncrementIdUsedAlphanumericIncrementId()
+    public function testIsIncrementIdUsedAlphanumericIncrementId()
     {
         $this->assertTrue($this->checker->isIncrementIdUsed('M00000001'));
     }