Tweak MethodsShouldBePublicOrPrivateRule to accept abstract protected methods

Author: Kocal

README.md

@@ -662,6 +662,8 @@ final class Alert
 Enforces that all methods in Twig Components are either public or private, but not protected.
 Since Twig Components must be final classes and inheritance is forbidden (see `ForbiddenInheritanceRule`), protected methods serve no purpose and should be avoided.
 
+**Exception:** Protected methods are allowed when they implement abstract methods defined in traits (e.g., `instantiateForm()` from `ComponentWithFormTrait`).
+
 ```yaml
 rules:
     - Kocal\PHPStanSymfonyUX\Rules\TwigComponent\MethodsShouldBePublicOrPrivateRule
@@ -716,6 +718,33 @@ final class Alert
 
 <br>
 
+```php
+// src/Twig/Components/PostForm.php
+namespace App\Twig\Components;
+
+use Symfony\Component\Form\FormInterface;
+use Symfony\UX\LiveComponent\Attribute\AsLiveComponent;
+use Symfony\UX\LiveComponent\ComponentWithFormTrait;
+use Symfony\UX\LiveComponent\DefaultActionTrait;
+
+#[AsLiveComponent]
+class PostForm
+{
+    use DefaultActionTrait;
+    use ComponentWithFormTrait;
+
+    // Implementing abstract method from ComponentWithFormTrait is allowed
+    protected function instantiateForm(): FormInterface
+    {
+        return $this->createForm(PostType::class);
+    }
+}
+```
+
+:+1:
+
+<br>
+
 ### PostMountMethodSignatureRule
 
 Enforces that methods with the `#[PostMount]` attribute have the correct signature: they must be public with an optional parameter of type `array`, and a return type of `array`, `void`, or `array|void`.

src/Rules/TwigComponent/MethodsShouldBePublicOrPrivateRule.php

@@ -8,6 +8,8 @@
 use PhpParser\Node;
 use PhpParser\Node\Stmt\Class_;
 use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\ClassReflection;
+use PHPStan\Reflection\ReflectionProvider;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
 use Symfony\UX\LiveComponent\Attribute\AsLiveComponent;
@@ -18,6 +20,11 @@
  */
 final class MethodsShouldBePublicOrPrivateRule implements Rule
 {
+    public function __construct(
+        private ReflectionProvider $reflectionProvider,
+    ) {
+    }
+
     public function getNodeType(): string
     {
         return Class_::class;
@@ -29,22 +36,102 @@ public function processNode(Node $node, Scope $scope): array
             return [];
         }
 
+        if ($node->namespacedName === null) {
+            return [];
+        }
+
+        $className = $node->namespacedName->toString();
+        if (! $this->reflectionProvider->hasClass($className)) {
+            return [];
+        }
+
         $errors = [];
+        $classReflection = $this->reflectionProvider->getClass($className);
+        $abstractTraitMethods = $this->getAbstractTraitMethods($classReflection);
 
         foreach ($node->getMethods() as $method) {
-            if ($method->isProtected()) {
-                $methodName = $method->name->toString();
+            if (! $method->isProtected()) {
+                continue;
+            }
+
+            $methodName = $method->name->toString();
+
+            // Skip if the method implements an abstract method from a trait
+            if (isset($abstractTraitMethods[$methodName])) {
+                continue;
+            }
+
+            $errors[] = RuleErrorBuilder::message(
+                sprintf('Method "%s()" in a Twig component should not be protected.', $methodName)
+            )
+                ->identifier('symfonyUX.twigComponent.methodsShouldBePublicOrPrivate')
+                ->line($method->getLine())
+                ->tip('Twig component methods should be either public or private, not protected.')
+                ->build();
+        }
+
+        // Check for protected concrete methods from traits that are not overridden in the class
+        $classDefinedMethods = [];
+        foreach ($node->getMethods() as $method) {
+            $classDefinedMethods[$method->name->toString()] = true;
+        }
+
+        foreach ($classReflection->getTraits() as $traitReflection) {
+            // Use native reflection to get trait methods
+            foreach ($traitReflection->getNativeReflection()->getMethods() as $traitMethod) {
+                if (! $traitMethod->isProtected()) {
+                    continue;
+                }
+
+                $methodName = $traitMethod->getName();
+
+                // Skip if method is abstract (already handled above)
+                if (isset($abstractTraitMethods[$methodName])) {
+                    continue;
+                }
+
+                // Skip if method is overridden in the class (already checked above)
+                if (isset($classDefinedMethods[$methodName])) {
+                    continue;
+                }
+
+                // Find the line number from the trait use statement
+                $lineNumber = $node->getLine();
+                foreach ($node->getTraitUses() as $traitUse) {
+                    $lineNumber = $traitUse->getLine();
+                    break;
+                }
 
                 $errors[] = RuleErrorBuilder::message(
                     sprintf('Method "%s()" in a Twig component should not be protected.', $methodName)
                 )
                     ->identifier('symfonyUX.twigComponent.methodsShouldBePublicOrPrivate')
-                    ->line($method->getLine())
+                    ->line($lineNumber)
                     ->tip('Twig component methods should be either public or private, not protected.')
                     ->build();
             }
         }
 
         return $errors;
     }
+
+    /**
+     * Get the list of abstract method names defined in traits used by the class.
+     *
+     * @return array<string, true>
+     */
+    private function getAbstractTraitMethods(ClassReflection $classReflection): array
+    {
+        $abstractTraitMethods = [];
+
+        foreach ($classReflection->getTraits() as $traitReflection) {
+            foreach ($traitReflection->getNativeReflection()->getMethods() as $method) {
+                if ($method->isAbstract()) {
+                    $abstractTraitMethods[$method->getName()] = true;
+                }
+            }
+        }
+
+        return $abstractTraitMethods;
+    }
 }

tests/Rules/TwigComponent/MethodsShouldBePublicOrPrivateRule/Fixture/ComponentWithProtectedConcreteMethodFromTrait.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kocal\PHPStanSymfonyUX\Tests\Rules\TwigComponent\MethodsShouldBePublicOrPrivateRule\Fixture;
+
+use Symfony\UX\TwigComponent\Attribute\AsTwigComponent;
+
+#[AsTwigComponent]
+class ComponentWithProtectedConcreteMethodFromTrait
+{
+    use TestTraitWithConcreteMethod;
+
+    public string $name = '';
+
+    // protectedConcreteTraitMethod() comes from the trait and is NOT abstract - SHOULD trigger an error
+}

tests/Rules/TwigComponent/MethodsShouldBePublicOrPrivateRule/Fixture/ComponentWithProtectedMethodFromTrait.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kocal\PHPStanSymfonyUX\Tests\Rules\TwigComponent\MethodsShouldBePublicOrPrivateRule\Fixture;
+
+use Symfony\UX\TwigComponent\Attribute\AsTwigComponent;
+
+#[AsTwigComponent]
+class ComponentWithProtectedMethodFromTrait
+{
+    use TestTraitWithAbstractMethod;
+
+    public string $name = '';
+
+    protected function protectedAbstractTraitMethod(): void
+    {
+        // Implementation of abstract method from trait - should NOT trigger an error
+    }
+}

tests/Rules/TwigComponent/MethodsShouldBePublicOrPrivateRule/Fixture/LiveComponentWithProtectedConcreteMethodFromTrait.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kocal\PHPStanSymfonyUX\Tests\Rules\TwigComponent\MethodsShouldBePublicOrPrivateRule\Fixture;
+
+use Symfony\UX\LiveComponent\Attribute\AsLiveComponent;
+
+#[AsLiveComponent]
+class LiveComponentWithProtectedConcreteMethodFromTrait
+{
+    use TestTraitWithConcreteMethod;
+
+    public string $name = '';
+
+    // protectedConcreteTraitMethod() comes from the trait and is NOT abstract - SHOULD trigger an error
+}

tests/Rules/TwigComponent/MethodsShouldBePublicOrPrivateRule/Fixture/LiveComponentWithProtectedMethodFromTrait.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kocal\PHPStanSymfonyUX\Tests\Rules\TwigComponent\MethodsShouldBePublicOrPrivateRule\Fixture;
+
+use Symfony\UX\LiveComponent\Attribute\AsLiveComponent;
+
+#[AsLiveComponent]
+class LiveComponentWithProtectedMethodFromTrait
+{
+    use TestTraitWithAbstractMethod;
+
+    public string $name = '';
+
+    protected function protectedAbstractTraitMethod(): void
+    {
+        // Implementation of abstract method from trait - should NOT trigger an error
+    }
+}

tests/Rules/TwigComponent/MethodsShouldBePublicOrPrivateRule/Fixture/TestTraitWithAbstractMethod.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kocal\PHPStanSymfonyUX\Tests\Rules\TwigComponent\MethodsShouldBePublicOrPrivateRule\Fixture;
+
+trait TestTraitWithAbstractMethod
+{
+    abstract protected function protectedAbstractTraitMethod(): void;
+}

tests/Rules/TwigComponent/MethodsShouldBePublicOrPrivateRule/Fixture/TestTraitWithConcreteMethod.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kocal\PHPStanSymfonyUX\Tests\Rules\TwigComponent\MethodsShouldBePublicOrPrivateRule\Fixture;
+
+trait TestTraitWithConcreteMethod
+{
+    protected function protectedConcreteTraitMethod(): void
+    {
+    }
+}

tests/Rules/TwigComponent/MethodsShouldBePublicOrPrivateRule/MethodsShouldBePublicOrPrivateRuleTest.php

@@ -36,6 +36,29 @@ public function testViolations(): void
                 ],
             ]
         );
+
+        // Protected concrete (non-abstract) methods from traits should trigger an error
+        $this->analyse(
+            [__DIR__ . '/Fixture/ComponentWithProtectedConcreteMethodFromTrait.php'],
+            [
+                [
+                    'Method "protectedConcreteTraitMethod()" in a Twig component should not be protected.',
+                    12,
+                    'Twig component methods should be either public or private, not protected.',
+                ],
+            ]
+        );
+
+        $this->analyse(
+            [__DIR__ . '/Fixture/LiveComponentWithProtectedConcreteMethodFromTrait.php'],
+            [
+                [
+                    'Method "protectedConcreteTraitMethod()" in a Twig component should not be protected.',
+                    12,
+                    'Twig component methods should be either public or private, not protected.',
+                ],
+            ]
+        );
     }
 
     public function testNoViolations(): void
@@ -54,6 +77,17 @@ public function testNoViolations(): void
             [__DIR__ . '/Fixture/LiveComponentWithPublicAndPrivateMethods.php'],
             []
         );
+
+        // Protected methods implementing abstract trait methods should not trigger an error
+        $this->analyse(
+            [__DIR__ . '/Fixture/ComponentWithProtectedMethodFromTrait.php'],
+            []
+        );
+
+        $this->analyse(
+            [__DIR__ . '/Fixture/LiveComponentWithProtectedMethodFromTrait.php'],
+            []
+        );
     }
 
     public static function getAdditionalConfigFiles(): array