PR #5604 breaks operations on subresources for PUT operation on Resource when placeholders are named differently than "id"

[Aerendir]

API Platform version(s) affected: 3.1.13

Description
With PR #5546, was introduced the ability to operate on subresources also if the placeholders of the IDs are not named "id".

The PR #5604 actually breaks this feature.

If placeholders are named "id", the code continues to work as there is a fallback in ItemNormalizer that returns $data['id'] if the key uri_variables is not set in the $context:

core/src/Serializer/ItemNormalizer.php

Lines 87 to 91 in 92a81f0

	private function getContextUriVariables(array $data, $operation, array $context): array
	{
	if (!isset($context['uri_variables'])) {
	return ['id' => $data['id']];
	}

But, as the key uri_variables is now always removed, the method ItemNormalizer::getContextUriVariables() never works as it should.

The PR #5604 was published due to those issues:

• 3.1.11 - PUT does not work with ManyToMany deep nested relations #5587
• Cannot PATCH/PUT the resource which contains fields with IRI values #5603

Reading them behind the lines, they are originates from the same problem: both the Resource and the SubResource have the placeholder named "id".

This causes the confusion in ItemNormalizer that uses the wrong "id" key to retrieve the SubResource.

How to reproduce

Create two resources, for example Alpha and Beta
Create a field in Beta which is a relation to Alpha
Try to create/update Beta

Working on 3.1.12 | NOT working on 3.1.13

PATCH /betas/{beta_id}
{
  "alpha": "/alphas/{alpha_id}"
}

NOT Working on 3.1.12 | (Now) Working on 3.1.13

PATCH /betas/{id}
{
  "alpha": "/alphas/{id}"
}

Possible Solution

#5739

[soyuka]

I could not reproduce, please give me a full reproducer, or even better try to make this test fail: https://github.com/api-platform/core/pull/5743/files#diff-9e1ca94383b69fcdb49b1cc19b6e03b2ae37dc880cf2aee0bcdb33fea87e98d6

[Aerendir]

@soyuka , I've created a proof of concept of a failing scenario:

#5747

I have some problems running it, as it seems not finding the PUT endpoint for the resource.

Anyway, it reproduces the situation I have and that make versions >3.1.12 make my tests fail.

I added a tag to the scenario, so it can be run easily:

vendor/bin/behat --tags issue5736

Please, let me know if it is sufficient for you to understand the context and, if it is not, please, let me know and I will explain further ❤️

PS
I think this issue should be reopened as I suppose it was automatically closed by GitHub when the PR was merged...