Description

Comparing with Null Values doesn't work with embeddable.

Thanks @vsalvans who found the issue in #3440.

Todo

• Always add tests and ensure they pass. (PhpUnit)
• Always add tests and ensure they pass. (Behat)
• Update CHANGELOG.md file
• Add test for mondoDB ?

Help wanted

Issue n°1: Is there a better way to add a test for this bug ?

I wrote a lot of PhpUnits Tests code. First, I started to test the correct behavior of OrderFilter regarding embaddables. I modified \ApiPlatform\Core\Tests\Fixtures\TestBundle\Entity\Dummy to add a public $embeddedDummy; property.
By doing this, I was able to add a new test scenario under \ApiPlatform\Core\Tests\Bridge\Doctrine\Common\Filter\OrderFilterTestTrait::provideApplyTestArguments :

'embeddable_nulls_comparison' => [
    [
        'embeddedDummy.dummyName' => [
            'nulls_comparison' => 'nulls_largest',
        ],
    ],
    [
        'order' => [
            'embeddedDummy.dummyName' => 'asc',
        ],
    ],
],

Unfortunatly, adding a new property created several new entries in the API documentation which led me writing a lot of code for all other tests (eg: BooleanFilterTest, RangeFilterTest, etc...). Regarding the impacts in the tests (see above), I am not convinced it is the best way to go. Should I create more isolated tests specific to embeddable somewhere else ?

Issue n°2: behat tests fails

While all PhpUnit tests succeed, the behats tests fail. The first failing scenario is creating a new Dummy resource using GraphQL. The reason is that to create a new Dummy entity, it now needs the missing part of public $embeddedDummy; in the payload.
This encourages me thinking this is not the best way to go.

001 Scenario: Create an item with a subresource                                     # features/graphql/mutation.feature:428
      And the JSON node "data.createDummy.dummy.id" should be equal to "/dummies/2" # features/graphql/mutation.feature:451
        Failed to evaluate expression 'data.createDummy.dummy.id' (Exception)

Issue n°3: I didn't write tests for mongoDB, but tests are green.

Am I missing something here ? Also, I never used mongoDB, and I'm not even sure the bug affect this database.