MockTreeWalker should be an SqlWalker

tests/Doctrine/Tests/Mocks/NullSqlWalker.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Mocks;
+
+use Doctrine\DBAL\Connection;
+use Doctrine\ORM\Query\AST;
+use Doctrine\ORM\Query\Exec\AbstractSqlExecutor;
+use Doctrine\ORM\Query\SqlWalker;
+
+/**
+ * SqlWalker implementation that does not produce SQL.
+ */
+class NullSqlWalker extends SqlWalker
+{
+    public function walkSelectStatement(AST\SelectStatement $AST): string
+    {
+        return '';
+    }
+
+    public function walkUpdateStatement(AST\UpdateStatement $AST): string
+    {
+        return '';
+    }
+
+    public function walkDeleteStatement(AST\DeleteStatement $AST): string
+    {
+        return '';
+    }
+
+    public function getExecutor($AST): AbstractSqlExecutor
+    {
+        return new class extends AbstractSqlExecutor {
+            public function execute(Connection $conn, array $params, array $types): int
+            {
+                return 0;
+            }
+        };
+    }
+}

tests/Doctrine/Tests/ORM/Query/LanguageRecognitionTest.php

@@ -13,7 +13,7 @@
 use Doctrine\ORM\Query;
 use Doctrine\ORM\Query\ParserResult;
 use Doctrine\ORM\Query\QueryException;
-use Doctrine\Tests\Mocks\MockTreeWalker;
+use Doctrine\Tests\Mocks\NullSqlWalker;
 use Doctrine\Tests\OrmTestCase;
 
 use const PHP_EOL;
@@ -74,7 +74,7 @@ public function parseDql(string $dql, array $hints = []): ParserResult
         $parser = new Query\Parser($query);
 
         // We do NOT test SQL output here. That only unnecessarily slows down the tests!
-        $parser->setCustomOutputTreeWalker(MockTreeWalker::class);
+        $parser->setCustomOutputTreeWalker(NullSqlWalker::class);
 
         return $parser->parse();
     }