Failing test case for doctrine#4400

phpunit.xml.dist

@@ -23,14 +23,14 @@
         <ini name="error_reporting" value="-1" />
 
         <!-- Test connection parameters -->
-        <!-- Uncomment, otherwise SQLite runs
+
         <var name="db_driver" value="pdo_mysql"/>
         <var name="db_host" value="localhost" />
         <var name="db_port" value="3306"/>
         <var name="db_user" value="root" />
         <var name="db_password" value="" />
         <var name="db_dbname" value="doctrine_tests" />
-        -->
+
         <!--<var name="db_event_subscribers" value="Doctrine\DBAL\Event\Listeners\OracleSessionInit">-->
 
         <!-- Privileged user connection parameters. Used to create and drop the test database -->

tests/Doctrine/Tests/DBAL/Functional/LockModeTest.php

@@ -0,0 +1,70 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\DBAL\Functional;
+
+use Doctrine\DBAL\Connection;
+use Doctrine\DBAL\LockMode;
+use Doctrine\DBAL\Platforms\SqlitePlatform;
+use Doctrine\DBAL\Schema\Table;
+use Doctrine\DBAL\TransactionIsolationLevel;
+use Doctrine\Tests\DbalTestCase;
+use Doctrine\Tests\TestUtil;
+
+class LockModeTest extends DbalTestCase
+{
+    /** @var Connection */
+    private $c1;
+
+    /** @var Connection */
+    private $c2;
+
+    public function setUp(): void
+    {
+        $this->c1 = TestUtil::getConnection();
+        $this->c2 = TestUtil::getConnection();
+
+        $table = new Table('users');
+        $table->addColumn('id', 'integer');
+
+        $this->c1->getSchemaManager()->createTable($table);
+
+        if ($this->c2->getSchemaManager()->tablesExist('users')) {
+            return;
+        }
+
+        if ($this->c2->getDatabasePlatform() instanceof SqlitePlatform) {
+            self::markTestSkipped('This test cannot run on SQLite using an in-memory database');
+        }
+
+        self::fail('Separate connections do not seem to talk to the same database');
+    }
+
+    public function tearDown(): void
+    {
+        $this->c1->getSchemaManager()->dropTable('users');
+
+        $this->c1->close();
+        $this->c2->close();
+    }
+
+    public function testLockModeNoneDoesNotBreakTransactionIsolation(): void
+    {
+        $this->c1->setTransactionIsolation(TransactionIsolationLevel::READ_COMMITTED);
+        $this->c2->setTransactionIsolation(TransactionIsolationLevel::READ_COMMITTED);
+
+        $this->c1->beginTransaction();
+        $this->c2->beginTransaction();
+
+        $this->c1->insert('users', ['id' => 1]);
+
+        $query = 'SELECT id FROM users';
+        $query = $this->c2->getDatabasePlatform()->appendLockHint($query, LockMode::NONE);
+
+        self::assertFalse($this->c2->fetchOne($query));
+
+        $this->c1->commit();
+        $this->c2->commit();
+    }
+}