Transform `ItemNotFoundException` to constraint violation

[ihmels]

If a dereferenceable IRI is used in a request and no resource exists under this IRI, an
ItemNotFoundException is thrown, which results in a response with status code 500 with the
following content:

{
  "@context": "/api/contexts/Error",
  "@type": "hydra:Error",
  "hydra:title": "An error occurred",
  "hydra:description": "Internal Server Error"
}

The content of the request was:

{
  "product": "/api/products/not_existing"
}

This response is not very helpful for the user of the API. Therefore it would be better if such an
error could be converted into a validation error:

{
  "@context": "/api/contexts/ConstraintViolationList",
  "@type": "ConstraintViolationList",
  "hydra:title": "An error occurred",
  "hydra:description": "product: Item not found for \"/api/products/not_existing\".",
  "violations": [
    {
      "propertyPath": "product",
      "message": "Item not found for \"/api/products/not_existing\".",
      "code": null
    }
  ]
}

For this, we could use the mechanism by which type errors are collected during denormalization
(PartialDenormalizationException).

[soyuka]

Pretty sure we've a test for this, it should throw some 4xx exception instead.

For the constraint violation I suggest that we add an IriConstraint.

[ihmels]

Pretty sure we've a test for this, it should throw some 4xx exception instead.

Yes, you're right. I used the exception_to_status configuration and was not aware of overwriting the default config with it (which contains Symfony\Component\Serializer\Exception\ExceptionInterface = 400).

For the constraint violation I suggest that we add an IriConstraint.

Would you also use the mechanism of partial denormalization errors for this and then convert the ItemNotFoundException to an IriConstraint violation like in the following code?

core/src/Symfony/EventListener/DeserializeListener.php

Lines 98 to 119 in ccef472

	try {
	$request->attributes->set(
	'data',
	$this->serializer->deserialize($request->getContent(), $context['resource_class'], $format, $context)
	);
	} catch (PartialDenormalizationException $e) {
	$violations = new ConstraintViolationList();
	foreach ($e->getErrors() as $exception) {
	if (!$exception instanceof NotNormalizableValueException) {
	continue;
	}
	$message = (new Type($exception->getExpectedTypes() ?? []))->message;
	$parameters = [];
	if ($exception->canUseMessageForUser()) {
	$parameters['hint'] = $exception->getMessage();
	}
	$violations->add(new ConstraintViolation($this->translator->trans($message, ['{{ type }}' => implode('|', $exception->getExpectedTypes() ?? [])], 'validators'), $message, $parameters, null, $exception->getPath(), null, null, (string) $exception->getCode()));
	}
	if (0 !== \count($violations)) {
	throw new ValidationException($violations);
	}
	}

[soyuka]

Good question, I guess we could do something directly within deserialization? Not sure how PartialDenormalizationException works, nor how we transform exceptions to violations.

[soyuka]

closing as question

[ihmels]

This issue was fixed in #5844.

[mdesign83]

It's not working in API Platform 4.1, ItemNotFoundException(\sprintf('Item not found for "%s".', $iri)) is thrown, but later it's changed to 'Unable to generate an IRI for the item of type ...'.
Also, exception_to_status has no effect on this. Same code is still working under API Platform 3.3.