Add test to verify Auth.PasswordRehash.authenticators config path

The new test explicitly verifies that the code correctly traverses:
service->authenticators()->get('Form')->getIdentifier()->get('Password')

This ensures the new configuration format is properly used for password rehashing.

Author: steinkel

tests/TestCase/Controller/Component/LoginComponentTest.php

@@ -40,6 +40,7 @@ public function setUp(): void
         $this->component->initialize([]);
         $this->user = new \CakeDC\Users\Model\Entity\User([
             'id' => 'd602b053-9d10-4a1c-b05d-5674f68a1f3a',
+            'username' => 'testuser',
             'email' => 'test@example.com',
             'password' => 'password',
         ]);
@@ -59,4 +60,89 @@ public function testLoginRehash()
         $this->controller->setRequest($this->request);
         $this->component->handleLogin(false, false);
     }
+
+    /**
+     * Test that password rehash uses the new authenticators config path
+     *
+     * This test verifies that when Auth.PasswordRehash.authenticators is configured,
+     * the code correctly traverses: service->authenticators()->get('Form')->getIdentifier()->get('Password')
+     *
+     * @return void
+     */
+    public function testPasswordRehashUsesAuthenticatorsConfig()
+    {
+        // Configure the new authenticators path (clear any deprecated identifiers config)
+        \Cake\Core\Configure::write('Auth.PasswordRehash', [
+            'authenticators' => [
+                'Form' => 'Password',
+            ],
+        ]);
+
+        // Create a password identifier that needs rehash
+        $passwordIdentifier = $this->getMockBuilder(\Authentication\Identifier\PasswordIdentifier::class)
+            ->onlyMethods(['needsPasswordRehash'])
+            ->getMock();
+        // This expectation verifies the code reaches the identifier through authenticators path
+        $passwordIdentifier->expects($this->once())
+            ->method('needsPasswordRehash')
+            ->willReturn(false); // Return false to skip the actual save
+
+        $identifiers = new \Authentication\Identifier\IdentifierCollection([]);
+        $identifiers->set('Password', $passwordIdentifier);
+
+        // Mock Form authenticator that returns our identifier collection
+        $formAuthenticator = $this->getMockBuilder(\Authentication\Authenticator\FormAuthenticator::class)
+            ->disableOriginalConstructor()
+            ->onlyMethods(['getIdentifier'])
+            ->getMock();
+        // This expectation verifies getIdentifier() is called on the Form authenticator
+        $formAuthenticator->expects($this->atLeastOnce())
+            ->method('getIdentifier')
+            ->willReturn($identifiers);
+
+        // Mock authenticator collection
+        $authenticators = $this->getMockBuilder(\Authentication\Authenticator\AuthenticatorCollection::class)
+            ->disableOriginalConstructor()
+            ->onlyMethods(['has', 'get'])
+            ->getMock();
+        // This expectation verifies the code checks for 'Form' authenticator
+        $authenticators->expects($this->atLeastOnce())
+            ->method('has')
+            ->with('Form')
+            ->willReturn(true);
+        // This expectation verifies the code gets the 'Form' authenticator
+        $authenticators->expects($this->atLeastOnce())
+            ->method('get')
+            ->with('Form')
+            ->willReturn($formAuthenticator);
+
+        // Mock authentication service
+        $authenticationService = $this->getMockBuilder(AuthenticationService::class)
+            ->onlyMethods(['getResult', 'authenticators', 'identifiers'])
+            ->getMock();
+
+        $result = new Result($this->user->toArray(), Result::SUCCESS);
+        $authenticationService->expects($this->once())->method('getResult')->willReturn($result);
+        // This expectation verifies authenticators() is called (new config path)
+        $authenticationService->expects($this->atLeastOnce())
+            ->method('authenticators')
+            ->willReturn($authenticators);
+        // identifiers() should not be called for rehash since we cleared the deprecated config
+        $authenticationService->expects($this->never())
+            ->method('identifiers');
+
+        $identity = $this->getMockBuilder(Identity::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $identity->expects($this->once())
+            ->method('getOriginalData')
+            ->willReturn($this->user);
+
+        $this->request = $this->request->withAttribute('authentication', $authenticationService);
+        $this->request = $this->request->withAttribute('identity', $identity);
+        $this->request = $this->request->withMethod('POST');
+        $this->controller->setRequest($this->request);
+
+        $this->component->handleLogin(false, false);
+    }
 }