ENGCOM-4481: Resolve Issue : Search REST API returns wrong total_count #21713

 - Merge Pull Request #21713 from ronak2ram/magento2:fixed-issue-17295
 - Merged commits:
   1. 7c55811
   2. a546e14
   3. 9dc26cc

Author: magento-engcom-team

lib/internal/Magento/Framework/Search/Adapter/Mysql/Adapter.php

@@ -7,6 +7,7 @@
 
 use Magento\Framework\App\ResourceConnection;
 use Magento\Framework\DB\Ddl\Table;
+use Magento\Framework\DB\Select;
 use Magento\Framework\Search\Adapter\Mysql\Aggregation\Builder as AggregationBuilder;
 use Magento\Framework\Search\AdapterInterface;
 use Magento\Framework\Search\RequestInterface;
@@ -129,32 +130,35 @@ private function getConnection()
     /**
      * Get rows size
      *
+     * @param Select $query
      * @return int
      */
-    private function getSize($query)
+    private function getSize(Select $query): int
     {
         $sql = $this->getSelectCountSql($query);
         $parentSelect = $this->getConnection()->select();
         $parentSelect->from(['core_select' => $sql]);
         $parentSelect->reset(\Magento\Framework\DB\Select::COLUMNS);
         $parentSelect->columns('COUNT(*)');
         $totalRecords = $this->getConnection()->fetchOne($parentSelect);
+
         return intval($totalRecords);
     }
 
     /**
      * Reset limit and offset
      *
+     * @param Select $query
      * @return Select
      */
-    private function getSelectCountSql($query)
+    private function getSelectCountSql(Select $query): Select
     {
         foreach ($this->countSqlSkipParts as $part => $toSkip) {
             if ($toSkip) {
                 $query->reset($part);
             }
         }
+
         return $query;
     }
-
 }

lib/internal/Magento/Framework/Search/Test/Unit/Adapter/Mysql/AdapterTest.php

@@ -161,10 +161,16 @@ public function testQuery()
         $select = $this->getMockBuilder(\Magento\Framework\DB\Select::class)
             ->disableOriginalConstructor()
             ->getMock();
-        $this->connectionAdapter->expects($this->once())
+
+        $this->connectionAdapter->expects($this->exactly(2))
             ->method('select')
             ->willReturn($select);
 
+        $this->connectionAdapter->expects($this->once())
+            ->method('fetchOne')
+            ->with($select)
+            ->willReturn($selectResult['total']);
+
         $table = $this->getMockBuilder(\Magento\Framework\DB\Ddl\Table::class)
             ->disableOriginalConstructor()
             ->getMock();