Add ClassReflection::typeArgumentsOf($class)

src/Reflection/CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - Add `ConstantReflection` and `TyphoonReflector::reflectConstant()`.
+- Add `ClassReflection::typeArgumentsOf($class)`.
 
 ## [0.4.2] 2024-08-05
 

src/Reflection/ClassReflection.php

@@ -13,6 +13,7 @@
 use Typhoon\Reflection\Internal\Misc\NonSerializable;
 use Typhoon\Reflection\Internal\NativeAdapter\ClassAdapter;
 use Typhoon\Type\Type;
+use Typhoon\Type\types;
 use Typhoon\Type\Visitor\TemplateTypeResolver;
 use Typhoon\TypedMap\TypedMap;
 
@@ -199,6 +200,31 @@ public function isInstanceOf(string|NamedClassId|AnonymousClassId $class): bool
  || \array_key_exists($class->name, $this->data[Data::Interfaces]);
  }
 
+ /**
+ * @param non-empty-string|NamedClassId|AnonymousClassId $class
+ * @return list<Type>
+ */
+ public function typeArgumentsOf(string|NamedClassId|AnonymousClassId $class): array
+ {
+ if (\is_string($class)) {
+ $class = Id::class($class);
+ }
+
+ if ($this->id->equals($class)) {
+ return $this
+ ->templates()
+ ->map(static fn(TemplateReflection $template): Type => types::template($template->id))
+ ->toList();
+ }
+
+ if ($class instanceof AnonymousClassId) {
+ return [];
+ }
+
+ /** @psalm-suppress PossiblyInvalidArrayOffset */
+ return $this->data[Data::Parents][$class->name] ?? $this->data[Data::Interfaces][$class->name] ?? [];
+ }
+
  public function isClass(): bool
  {
  return $this->data[Data::ClassKind] === ClassKind::Class_;

tests/Reflection/functional_tests/class/type_arguments_of.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Typhoon\Reflection;
+
+use Typhoon\Reflection\Locator\Resource;
+use Typhoon\Type\types;
+use function PHPUnit\Framework\assertEquals;
+
+return static function (TyphoonReflector $reflector): void {
+ $iterator = $reflector->reflectClass(\Iterator::class);
+ assertEquals(
+ [types::classTemplate(\Iterator::class, 'TKey'), types::classTemplate(\Iterator::class, 'TValue')],
+ $iterator->typeArgumentsOf(\Iterator::class),
+ );
+ assertEquals(
+ [types::classTemplate(\Iterator::class, 'TKey'), types::classTemplate(\Iterator::class, 'TValue')],
+ $iterator->typeArgumentsOf(\Traversable::class),
+ );
+
+ $a = $reflector
+ ->withResource(Resource::fromCode(
+ <<<'PHP'
+ <?php
+
+ /**
+ * @implements Iterator<string>
+ */
+ abstract class A implements Iterator {}
+ PHP,
+ ))
+ ->reflectClass('A');
+ assertEquals(
+ [types::mixed, types::string],
+ $a->typeArgumentsOf(\Iterator::class),
+ );
+ assertEquals(
+ [types::mixed, types::string],
+ $a->typeArgumentsOf(\Traversable::class),
+ );
+};