Add test

Author: sebastianbergmann

tests/unit/Framework/MockObject/Creation/CreatePartialMockTest.php

@@ -12,6 +12,7 @@
 use PHPUnit\Framework\Attributes\Group;
 use PHPUnit\Framework\Attributes\Medium;
 use PHPUnit\Framework\Attributes\TestDox;
+use PHPUnit\Framework\MockObject\Generator\DuplicateMethodException;
 use PHPUnit\Framework\TestCase;
 use PHPUnit\TestFixture\MockObject\ExtendableClass;
 use ReflectionProperty;
@@ -32,6 +33,14 @@ public function testCreatesPartialMockObjectForExtendableClass(): void
         $this->assertTrue($mock->doSomething());
     }
 
+    public function testCannotCreatePartialMockObjectForExtendableClassWithDuplicateMethods(): void
+    {
+        $this->expectException(DuplicateMethodException::class);
+        $this->expectExceptionMessage('Cannot double using a method list that contains duplicates: "doSomethingElse, doSomethingElse" (duplicate: "doSomethingElse")');
+
+        $this->createPartialMock(ExtendableClass::class, ['doSomethingElse', 'doSomethingElse']);
+    }
+
     public function testMethodOfPartialMockThatIsNotConfigurableCannotBeConfigured(): void
     {
         $mock = $this->createPartialMock(ExtendableClass::class, ['doSomethingElse']);