MAGETWO-59400: Invalid join condition in Product Flat Indexer

- Add integration test.

Author: AlexeyManenok

dev/tests/integration/framework/Magento/TestFramework/Catalog/Model/Indexer/Product/Flat/Action/Full.php

@@ -0,0 +1,22 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+declare(strict_types=1);
+
+namespace Magento\TestFramework\Catalog\Model\Indexer\Product\Flat\Action;
+
+/**
+ * Class Full reindex action
+ */
+class Full extends \Magento\Catalog\Model\Indexer\Product\Flat\Action\Full
+{
+    /**
+     * List of product types available in installation
+     *
+     * @var array
+     */
+    protected $_productTypes;
+}

dev/tests/integration/testsuite/Magento/Catalog/Model/Indexer/Product/Flat/Action/RelationTest.php

@@ -0,0 +1,134 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+declare(strict_types=1);
+
+namespace Magento\Catalog\Model\Indexer\Product\Flat\Action;
+
+use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\DB\Adapter\AdapterInterface;
+use Magento\Store\Model\StoreManagerInterface;
+use Magento\TestFramework\Catalog\Model\Indexer\Product\Flat\Action\Full as FlatIndexerFull;
+
+/**
+ * Test relation customization
+ */
+class RelationTest extends \Magento\TestFramework\Indexer\TestCase
+{
+    /**
+     * @var FlatIndexerFull
+     */
+    private $indexer;
+
+    /**
+     * @var StoreManagerInterface
+     */
+    private $storeManager;
+
+    /**
+     * @var AdapterInterface
+     */
+    private $connection;
+
+    /**
+     * Updated flat tables
+     *
+     * @var array
+     */
+    private $flatUpdated = [];
+
+    /**
+     * @inheritdoc
+     */
+    protected function setUp()
+    {
+        $objectManager = \Magento\TestFramework\Helper\Bootstrap::getObjectManager();
+
+        $tableBuilderMock = $this->createMock(\Magento\Catalog\Model\Indexer\Product\Flat\TableBuilder::class);
+        $flatTableBuilderMock = $this->createMock(\Magento\Catalog\Model\Indexer\Product\Flat\FlatTableBuilder::class);
+
+        $productIndexerHelper = $objectManager->create(
+            \Magento\Catalog\Helper\Product\Flat\Indexer::class,
+            ['addChildData' => 1]
+        );
+        $this->indexer = $objectManager->create(
+            FlatIndexerFull::class,
+            [
+                'productHelper' => $productIndexerHelper,
+                'tableBuilder' => $tableBuilderMock,
+                'flatTableBuilder' => $flatTableBuilderMock
+            ]
+        );
+        $this->storeManager = $objectManager->create(StoreManagerInterface::class);
+        $this->connection = $objectManager->get(ResourceConnection::class)->getConnection();
+
+        foreach ($this->storeManager->getStores() as $store) {
+            $flatTable = $productIndexerHelper->getFlatTableName($store->getId());
+            if ($this->connection->isTableExists($flatTable) &&
+                !$this->connection->tableColumnExists($flatTable, 'child_id') &&
+                !$this->connection->tableColumnExists($flatTable, 'is_child')
+            ) {
+                $this->connection->addColumn(
+                    $flatTable,
+                    'child_id',
+                    [
+                        'type' => 'integer',
+                        'length' => null,
+                        'unsigned' => true,
+                        'nullable' => true,
+                        'default' => null,
+                        'unique' => true,
+                        'comment' => 'Child Id',
+                    ]
+                );
+                $this->connection->addColumn(
+                    $flatTable,
+                    'is_child',
+                    [
+                        'type' => 'smallint',
+                        'length' => 1,
+                        'unsigned' => true,
+                        'nullable' => false,
+                        'default' => '0',
+                        'comment' => 'Checks If Entity Is Child',
+                    ]
+                );
+
+                $this->flatUpdated[] = $flatTable;
+            }
+        }
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function tearDown()
+    {
+        foreach ($this->flatUpdated as $flatTable) {
+            $this->connection->dropColumn($flatTable, 'child_id');
+            $this->connection->dropColumn($flatTable, 'is_child');
+        }
+    }
+
+    /**
+     * Test that SQL generated for relation customization is valid
+     *
+     * @return void
+     * @throws \Magento\Framework\Exception\LocalizedException
+     * @throws \Exception
+     */
+    public function testExecute() : void
+    {
+        try {
+            $this->indexer->execute();
+        } catch (\Magento\Framework\Exception\LocalizedException $e) {
+            if ($e->getPrevious() instanceof \Zend_Db_Statement_Exception) {
+                $this->fail($e->getMessage());
+            }
+            throw $e;
+        }
+    }
+}