MC-38806: Wrong table comment after reindex

Author: OlgaVasyltsun

app/code/Magento/Catalog/Model/ResourceModel/Indexer/ActiveTableSwitcher.php

@@ -40,23 +40,22 @@ public function switchTable(\Magento\Framework\DB\Adapter\AdapterInterface $conn
             $outdatedTableName = $tableName . $this->outdatedTableSuffix;
             $replicaTableName = $tableName . $this->additionalTableSuffix;
 
-            $tableComment = $connection->showTableStatus($tableName)['Comment'];
-
-            $replicaComment = $connection->showTableStatus($replicaTableName)['Comment'];
+            $tableComment = $connection->showTableStatus($tableName)['Comment'] ?? '';
+            $replicaComment = $connection->showTableStatus($replicaTableName)['Comment'] ?? '';
 
             $renameBatch = [
                 [
                     'oldName' => $tableName,
-                    'newName' => $outdatedTableName
+                    'newName' => $outdatedTableName,
                 ],
                 [
                     'oldName' => $replicaTableName,
-                    'newName' => $tableName
+                    'newName' => $tableName,
                 ],
                 [
                     'oldName' => $outdatedTableName,
-                    'newName' => $replicaTableName
-                ]
+                    'newName' => $replicaTableName,
+                ],
             ];
 
             $toRename[] = $renameBatch;

app/code/Magento/Catalog/Test/Unit/Model/ResourceModel/Indexer/ActiveTableSwitcherTest.php

@@ -9,59 +9,88 @@
 
 use Magento\Catalog\Model\ResourceModel\Indexer\ActiveTableSwitcher;
 use Magento\Framework\DB\Adapter\AdapterInterface;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
+/**
+ * Unit test for \Magento\Catalog\Model\ResourceModel\Indexer\ActiveTableSwitcher class.
+ */
 class ActiveTableSwitcherTest extends TestCase
 {
     /**
      * @var ActiveTableSwitcher
      */
     private $model;
 
+    /**
+     * @inheritdoc
+     */
     protected function setUp(): void
     {
         $this->model = new ActiveTableSwitcher();
     }
 
+    /**
+     * @return void
+     */
     public function testSwitch()
     {
+        /** @var AdapterInterface|MockObject $connectionMock */
         $connectionMock = $this->getMockBuilder(AdapterInterface::class)
             ->addMethods(['changeTableComment'])
             ->disableOriginalConstructor()
             ->getMockForAbstractClass();
+        $statement = $this->createMock(\Zend_Db_Statement_Interface::class);
         $tableName = 'tableName';
         $tableData = ['Comment' => 'Table comment'];
         $replicaName = 'tableName_replica';
         $replicaData = ['Comment' => 'Table comment replica'];
 
-        $connectionMock->expects($this->any())->method('showTableStatus')->willReturn($replicaData);
-
-        $connectionMock->expects($this->any())->method('showTableStatus')->willReturn($tableData);
+        $connectionMock->expects($this->exactly(2))
+            ->method('showTableStatus')
+            ->withConsecutive(
+                [$tableName],
+                [$replicaName]
+            )
+            ->willReturnOnConsecutiveCalls(
+                $tableData,
+                $replicaData
+            );
 
-        $connectionMock->expects($this->any())->method('changeTableComment')->with($tableName, $replicaData['Comment']);
+        $connectionMock->expects($this->exactly(2))
+            ->method('changeTableComment')
+            ->withConsecutive(
+                [$tableName, $replicaData['Comment']],
+                [$replicaName, $tableData['Comment']]
+            )
+            ->willReturn($statement);
 
-        $connectionMock->expects($this->any())->method('changeTableComment')->with($replicaName, $tableData['Comment']);
-
-        $connectionMock->expects($this->once())->method('renameTablesBatch')->with(
-            [
-                [
-                    'oldName' => 'tableName',
-                    'newName' => 'tableName_outdated'
-                ],
-                [
-                    'oldName' => 'tableName_replica',
-                    'newName' => 'tableName'
-                ],
+        $connectionMock->expects($this->once())
+            ->method('renameTablesBatch')
+            ->with(
                 [
-                    'oldName' => 'tableName_outdated',
-                    'newName' => 'tableName_replica'
-                ],
-            ]
-        );
+                    [
+                        'oldName' => 'tableName',
+                        'newName' => 'tableName_outdated'
+                    ],
+                    [
+                        'oldName' => 'tableName_replica',
+                        'newName' => 'tableName'
+                    ],
+                    [
+                        'oldName' => 'tableName_outdated',
+                        'newName' => 'tableName_replica'
+                    ],
+                ]
+            )
+            ->willReturn(true);
 
         $this->model->switchTable($connectionMock, [$tableName]);
     }
 
+    /**
+     * @return void
+     */
     public function testGetAdditionalTableName()
     {
         $tableName = 'table_name';