Add tests cloning of test double objects

tests/_files/mock-object/ExtendableClassWithCloneMethod.php

@@ -0,0 +1,28 @@
+<?php declare(strict_types=1);
+/*
+ * This file is part of PHPUnit.
+ *
+ * (c) Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+namespace PHPUnit\TestFixture\MockObject;
+
+use Exception;
+
+class ExtendableClassWithCloneMethod
+{
+    /**
+     * @throws Exception
+     */
+    public function __clone(): void
+    {
+        throw new Exception(__METHOD__);
+    }
+
+    public function method(): bool
+    {
+        return true;
+    }
+}

tests/unit/Framework/MockObject/TestDoubleTestCase.php

@@ -12,6 +12,7 @@
 use Exception;
 use PHPUnit\Framework\Attributes\TestDox;
 use PHPUnit\Framework\TestCase;
+use PHPUnit\TestFixture\MockObject\ExtendableClassWithCloneMethod;
 use PHPUnit\TestFixture\MockObject\InterfaceWithMethodThatExpectsObject;
 use PHPUnit\TestFixture\MockObject\InterfaceWithReturnTypeDeclaration;
 use stdClass;
@@ -184,6 +185,25 @@ final public function testMethodCanBeConfiguredToThrowAnException(): void
         $this->fail();
     }
 
+    #[TestDox('Original __clone() method is not called by default when test double object is cloned')]
+    public function testOriginalCloneMethodIsNotCalledByDefaultWhenTestDoubleObjectIsCloned(): void
+    {
+        $double = clone $this->createTestDouble(ExtendableClassWithCloneMethod::class);
+
+        $this->assertFalse($double->method());
+    }
+
+    #[TestDox('Original __clone() method can optionally be called when test double object is cloned')]
+    public function testOriginalCloneMethodCanOptionallyBeCalledWhenTestDoubleObjectIsCloned(): void
+    {
+        $double = $this->getMockBuilder(ExtendableClassWithCloneMethod::class)->enableOriginalClone()->getMock();
+
+        $this->expectException(Exception::class);
+        $this->expectExceptionMessage(ExtendableClassWithCloneMethod::class . '::__clone');
+
+        clone $double;
+    }
+
     /**
      * @psalm-template RealInstanceType of object
      *