Merge pull request #22 from DaveLiddament/feature/restrict-trait-to

ADD RestrictTraitTo rule

Author: DaveLiddament

README.md

@@ -17,6 +17,7 @@ This is an extension for [PHPStan](https://phpstan.org) for adding analysis for
 - [MustUseResult](https://github.com/DaveLiddament/php-language-extensions#mustUseResult)
 - [NamespaceVisibility](https://github.com/DaveLiddament/php-language-extensions#namespaceVisibility)
 - [Package](https://github.com/DaveLiddament/php-language-extensions#package) 
+- [Restrict Trait To](https://github.com/DaveLiddament/php-language-extensions#retrictTraitTo)
 - [Test Tag](https://github.com/DaveLiddament/php-language-extensions#testtag)
 
 ## Installation

src/Rules/RestrictTraitToRule.php

@@ -0,0 +1,79 @@
+<?php
+
+namespace DaveLiddament\PhpstanPhpLanguageExtensions\Rules;
+
+use DaveLiddament\PhpLanguageExtensions\RestrictTraitTo;
+use DaveLiddament\PhpstanPhpLanguageExtensions\AttributeValueReaders\AttributeFinder;
+use DaveLiddament\PhpstanPhpLanguageExtensions\AttributeValueReaders\AttributeValueReader;
+use DaveLiddament\PhpstanPhpLanguageExtensions\Helpers\Cache;
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\ReflectionProvider;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+use PHPStan\Type\ObjectType;
+
+/** @implements Rule<Node\Stmt\TraitUse> */
+final class RestrictTraitToRule implements Rule
+{
+    /**
+     * @var Cache<string|null>
+     */
+    private Cache $cache;
+
+    public function __construct(
+        private ReflectionProvider $reflectionProvider,
+    ) {
+        $this->cache = new Cache();
+    }
+
+    public function getNodeType(): string
+    {
+        return Node\Stmt\TraitUse::class;
+    }
+
+    public function processNode(Node $node, Scope $scope): array
+    {
+        $containingClassName = $scope->getClassReflection()?->getName();
+
+        if (null === $containingClassName) {
+            return [];
+        }
+
+        $containingClassObjectType = new ObjectType($containingClassName);
+
+        foreach ($node->traits as $trait) {
+            $classReflection = $this->reflectionProvider->getClass($trait->toCodeString())->getNativeReflection();
+
+            if ($this->cache->hasEntry($classReflection)) {
+                $restrictTraitToClassName = $this->cache->getEntry($classReflection);
+            } else {
+                $restrictTraitTo = AttributeFinder::getAttributeOnClass($classReflection, RestrictTraitTo::class);
+
+                if (null === $restrictTraitTo) {
+                    $restrictTraitToClassName = null;
+                } else {
+                    $restrictTraitToClassName = AttributeValueReader::getString($restrictTraitTo, 0, 'className');
+                }
+
+                $this->cache->addEntry($classReflection, $restrictTraitToClassName);
+            }
+
+            if (null === $restrictTraitToClassName) {
+                continue;
+            }
+
+            $restrictTraitToObjectType = new ObjectType($restrictTraitToClassName);
+
+            if (!$restrictTraitToObjectType->isSuperTypeOf($containingClassObjectType)->yes()) {
+                return [
+                    RuleErrorBuilder::message("Trait can only be used on class or child of: $restrictTraitToClassName")
+                        ->identifier('phpExtensionLibrary.restrictTraitTo')
+                        ->build(),
+                ];
+            }
+        }
+
+        return [];
+    }
+}

tests/Rules/RestrictTraitToTest.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DaveLiddament\PhpstanPhpLanguageExtensions\Tests\Rules;
+
+use DaveLiddament\PhpstanPhpLanguageExtensions\Rules\RestrictTraitToRule;
+use DaveLiddament\PhpstanRuleTestHelper\AbstractRuleTestCase;
+use PHPStan\Rules\Rule;
+
+/** @extends AbstractRuleTestCase<RestrictTraitToRule> */
+final class RestrictTraitToTest extends AbstractRuleTestCase
+{
+    protected function getRule(): Rule
+    {
+        return new RestrictTraitToRule($this->createReflectionProvider());
+    }
+
+    public function testRestrictTraitTo(): void
+    {
+        $this->assertIssuesReported(
+            __DIR__.'/data/restrictTraitTo/restrictTraitTo.php',
+        );
+    }
+
+    protected function getErrorFormatter(): string
+    {
+        return 'Trait can only be used on class or child of: {0}';
+    }
+}

tests/Rules/data/restrictTraitTo/restrictTraitTo.php

@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+namespace RestrictTraitTo;
+
+use DaveLiddament\PhpLanguageExtensions\RestrictTraitTo;
+
+trait UseAnywhere {}
+
+#[RestrictTraitTo(Interface1::class)]
+trait UseOnlyOnInterface1 {}
+
+#[RestrictTraitTo(AbstractClass1::class)]
+trait UseOnlyOnAbstractClass1 {}
+
+#[RestrictTraitTo(Class2::class)]
+trait UseOnlyOnClass2 {}
+
+
+interface Interface1 {}
+
+
+class AClass {
+    use UseAnywhere; // OK
+    use UseOnlyOnInterface1; // ERROR RestrictTraitTo\Interface1
+    use UseOnlyOnAbstractClass1; // ERROR RestrictTraitTo\AbstractClass1
+    use UseOnlyOnClass2; // ERROR RestrictTraitTo\Class2
+}
+
+
+class ImplementsInterface1 implements Interface1 {
+    use UseAnywhere; // OK
+    use UseOnlyOnInterface1; // OK
+    use UseOnlyOnAbstractClass1; // ERROR RestrictTraitTo\AbstractClass1
+    use UseOnlyOnClass2; // ERROR RestrictTraitTo\Class2
+}
+
+abstract class AbstractClass1
+{
+
+}
+
+class ExtendsAbstractClass1 extends AbstractClass1 {
+    use UseAnywhere; // OK
+    use UseOnlyOnInterface1; // ERROR RestrictTraitTo\Interface1
+    use UseOnlyOnAbstractClass1; // OK
+    use UseOnlyOnClass2; // ERROR RestrictTraitTo\Class2
+}
+
+class Class2 {
+    use UseAnywhere; // OK
+    use UseOnlyOnInterface1; // ERROR RestrictTraitTo\Interface1
+    use UseOnlyOnAbstractClass1; // ERROR RestrictTraitTo\AbstractClass1
+    use UseOnlyOnClass2; // OK
+}