fix: nullable properties not seen as nullable by TypeReflector (#591)

Co-authored-by: Brent Roose <[email protected]>

Author: ainesophaur

src/Tempest/Reflection/src/TypeReflector.php

@@ -39,10 +39,13 @@
 
     private string $cleanDefinition;
 
+    private bool $isNullable;
+
     public function __construct(
         private PHPReflector|PHPReflectionType|string $reflector,
     ) {
         $this->definition = $this->resolveDefinition($this->reflector);
+        $this->isNullable = $this->resolveIsNullable($this->reflector);
         $this->cleanDefinition = str_replace('?', '', $this->definition);
     }
 
@@ -62,7 +65,7 @@ public function equals(string|TypeReflector $type): bool
 
     public function accepts(mixed $input): bool
     {
-        if ($this->isNullable() && $input === null) {
+        if ($this->isNullable && $input === null) {
             return true;
         }
 
@@ -152,8 +155,7 @@ public function isIterable(): bool
 
     public function isNullable(): bool
     {
-        return str_contains($this->definition, '?')
-            || str_contains($this->definition, 'null');
+        return $this->isNullable;
     }
 
     /** @return self[] */
@@ -202,4 +204,24 @@ private function resolveDefinition(PHPReflector|PHPReflectionType|string $reflec
 
         throw new Exception('Could not resolve type');
     }
+
+    private function resolveIsNullable(PHPReflectionType|PHPReflector|string $reflector): bool
+    {
+        if (is_string($reflector)) {
+            return str_contains($this->definition, '?') || str_contains($this->definition, 'null');
+        }
+
+        if (
+            $reflector instanceof PHPReflectionParameter
+            || $reflector instanceof PHPReflectionProperty
+        ) {
+            return $reflector->getType()->allowsNull();
+        }
+
+        if ($reflector instanceof PHPReflectionType) {
+            return $reflector->allowsNull();
+        }
+
+        return false;
+    }
 }

src/Tempest/Reflection/tests/ClassReflectorTest.php

@@ -8,6 +8,7 @@
 use ReflectionClass;
 use Tempest\Reflection\ClassReflector;
 use Tempest\Reflection\Tests\Fixtures\TestClassA;
+use Tempest\Reflection\Tests\Fixtures\TestClassB;
 
 /**
  * @internal
@@ -36,4 +37,10 @@ public function test_getting_short_name(): void
 
         $this->assertSame($reflector->getShortName(), $reflection->getShortName());
     }
+
+    public function test_nullable_property_type(): void
+    {
+        $reflector = new ClassReflector(TestClassB::class);
+        $this->assertTrue($reflector->getProperty('name')->isNullable());
+    }
 }

src/Tempest/Reflection/tests/Fixtures/TestClassB.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tempest\Reflection\Tests\Fixtures;
+
+final class TestClassB
+{
+    public function __construct(
+        public ?string $name,
+    ) {
+    }
+}