Fix fatal error when subresource type is not defined

Currently, when a property has a @ApiSubresource declaration, but no
proper type declaration, this results in a "Fatal error: Call to a
member function isCollection() on null", which is hard to debug.
Instead throw an exception referencing the offending property, so the
declaration can be fixed.

Additionally, add some unit tests for the
AnnotationSubresourceMetadataFactory.

Author: oxan

src/Metadata/Property/Factory/AnnotationSubresourceMetadataFactory.php

@@ -14,6 +14,7 @@
 namespace ApiPlatform\Core\Metadata\Property\Factory;
 
 use ApiPlatform\Core\Annotation\ApiSubresource;
+use ApiPlatform\Core\Exception\InvalidResourceException;
 use ApiPlatform\Core\Metadata\Property\PropertyMetadata;
 use ApiPlatform\Core\Metadata\Property\SubresourceMetadata;
 use ApiPlatform\Core\Util\Reflection;
@@ -52,7 +53,7 @@ public function create(string $resourceClass, string $property, array $options =
             $annotation = $this->reader->getPropertyAnnotation($reflectionClass->getProperty($property), ApiSubresource::class);
 
             if (null !== $annotation) {
-                return $this->updateMetadata($annotation, $propertyMetadata, $resourceClass);
+                return $this->updateMetadata($annotation, $propertyMetadata, $resourceClass, $property);
             }
         }
 
@@ -70,16 +71,19 @@ public function create(string $resourceClass, string $property, array $options =
             $annotation = $this->reader->getMethodAnnotation($reflectionMethod, ApiSubresource::class);
 
             if (null !== $annotation) {
-                return $this->updateMetadata($annotation, $propertyMetadata, $resourceClass);
+                return $this->updateMetadata($annotation, $propertyMetadata, $resourceClass, $property);
             }
         }
 
         return $propertyMetadata;
     }
 
-    private function updateMetadata(ApiSubresource $annotation, PropertyMetadata $propertyMetadata, string $originResourceClass): PropertyMetadata
+    private function updateMetadata(ApiSubresource $annotation, PropertyMetadata $propertyMetadata, string $originResourceClass, string $propertyName): PropertyMetadata
     {
         $type = $propertyMetadata->getType();
+        if (null === $type) {
+            throw new InvalidResourceException(sprintf('Property "%s" on resource "%s" is declared as a subresource, but its type could not be determined.', $propertyName, $originResourceClass));
+        }
         $isCollection = $type->isCollection();
         $resourceClass = $isCollection ? $type->getCollectionValueType()->getClassName() : $type->getClassName();
         $maxDepth = $annotation->maxDepth;

tests/Metadata/Property/Factory/AnnotationSubresourceMetadataFactoryTest.php

@@ -0,0 +1,78 @@
+<?php
+
+/*
+ * This file is part of the API Platform project.
+ *
+ * (c) Kévin Dunglas <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace ApiPlatform\Core\Tests\Metadata\Property\Factory;
+
+use ApiPlatform\Core\Annotation\ApiSubresource;
+use ApiPlatform\Core\Metadata\Property\Factory\AnnotationSubresourceMetadataFactory;
+use ApiPlatform\Core\Metadata\Property\Factory\PropertyMetadataFactoryInterface;
+use ApiPlatform\Core\Metadata\Property\PropertyMetadata;
+use ApiPlatform\Core\Metadata\Property\SubresourceMetadata;
+use ApiPlatform\Core\Tests\Fixtures\TestBundle\Entity\Dummy;
+use ApiPlatform\Core\Tests\Fixtures\TestBundle\Entity\RelatedDummy;
+use Doctrine\Common\Annotations\Reader;
+use Doctrine\Common\Collections\ArrayCollection;
+use PHPUnit\Framework\TestCase;
+use Prophecy\Argument;
+use Prophecy\Prophecy\ProphecyInterface;
+use Symfony\Component\PropertyInfo\Type;
+
+class AnnotationSubresourceMetadataFactoryTest extends TestCase
+{
+    /**
+     * @dataProvider getDependencies
+     */
+    public function testCreateProperty(ProphecyInterface $reader, ProphecyInterface $decorated = null)
+    {
+        $factory = new AnnotationSubresourceMetadataFactory($reader->reveal(), $decorated->reveal());
+        $metadata = $factory->create(Dummy::class, 'relatedDummies');
+
+        $this->assertEquals(new SubresourceMetadata(RelatedDummy::class, true, null), $metadata->getSubresource());
+    }
+
+    public function getDependencies()
+    {
+        $annotation = new ApiSubresource();
+
+        $propertyReaderProphecy = $this->prophesize(Reader::class);
+        $propertyReaderProphecy->getPropertyAnnotation(Argument::type(\ReflectionProperty::class), ApiSubresource::class)->willReturn($annotation)->shouldBeCalled();
+
+        $relatedDummyType = new Type(Type::BUILTIN_TYPE_OBJECT, false, RelatedDummy::class);
+        $subresourceType = new Type(Type::BUILTIN_TYPE_OBJECT, false, ArrayCollection::class, true, new Type(Type::BUILTIN_TYPE_INT), $relatedDummyType);
+
+        $decoratedReturnProphecy = $this->prophesize(PropertyMetadataFactoryInterface::class);
+        $decoratedReturnProphecy->create(Dummy::class, 'relatedDummies', [])->willReturn(new PropertyMetadata($subresourceType, 'Several dummies'))->shouldBeCalled();
+
+        return [
+            [$propertyReaderProphecy, $decoratedReturnProphecy],
+        ];
+    }
+
+    /**
+     * @expectedException \ApiPlatform\Core\Exception\InvalidResourceException
+     * @expectedExceptionMessage Property "relatedDummies" on resource "ApiPlatform\Core\Tests\Fixtures\TestBundle\Entity\Dummy" is declared as a subresource, but its type could not be determined.
+     */
+    public function testCreatePropertyUnknownType()
+    {
+        $annotation = new ApiSubresource();
+
+        $propertyReaderProphecy = $this->prophesize(Reader::class);
+        $propertyReaderProphecy->getPropertyAnnotation(Argument::type(\ReflectionProperty::class), ApiSubresource::class)->willReturn($annotation)->shouldBeCalled();
+
+        $decoratedReturnProphecy = $this->prophesize(PropertyMetadataFactoryInterface::class);
+        $decoratedReturnProphecy->create(Dummy::class, 'relatedDummies', [])->willReturn(new PropertyMetadata(null, 'Several dummies'))->shouldBeCalled();
+
+        $factory = new AnnotationSubresourceMetadataFactory($propertyReaderProphecy->reveal(), $decoratedReturnProphecy->reveal());
+        $metadata = $factory->create(Dummy::class, 'relatedDummies');
+    }
+}