Add test for Mysqli\Result

tests/Functional/Driver/Mysqli/ResultTest.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\DBAL\Tests\Functional\Driver\Mysqli;
+
+use Doctrine\DBAL\Tests\FunctionalTestCase;
+use Doctrine\DBAL\Tests\TestUtil;
+
+/** @requires extension mysqli */
+final class ResultTest extends FunctionalTestCase
+{
+    protected function setUp(): void
+    {
+        if (TestUtil::isDriverOneOf('mysqli')) {
+            $this->connection->executeQuery('CREATE TABLE my_table (my_col_1 INT NOT NULL);');
+
+            return;
+        }
+
+        self::markTestSkipped('This test requires the mysqli driver.');
+    }
+
+    protected function tearDown(): void
+    {
+        $this->connection->executeStatement('DROP TABLE IF EXISTS my_table;');
+    }
+
+    public function testSuccessfulRowCountFromAffectedRows(): void
+    {
+        self::assertSame(0, $this->connection->getNativeConnection()->affected_rows);
+
+        $result = $this->connection->executeQuery('INSERT INTO my_table VALUES(7);');
+
+        self::assertSame(1, $this->connection->getNativeConnection()->affected_rows);
+        self::assertSame(1, $result->rowCount());
+    }
+
+    public function testFailingRowCountFromAffectedRows(): void
+    {
+        self::assertSame(0, $this->connection->getNativeConnection()->affected_rows);
+
+        // @todo: Find a query or a command sequence capable to reproduce the -1 result.
+        $result = $this->connection->executeQuery('INSERT INTO my_table VALUES(7);');
+
+        self::assertSame(-1, $this->connection->getNativeConnection()->affected_rows);
+        self::assertSame(-1, $result->rowCount());
+    }
+}