fix(doctrine): support integer-backed enums in BackedEnumFilter

[MeronNagy]

Q	A
Branch?	4.1
Tickets	#7126
License	MIT
Doc PR

Currently BackedEnumFilter displays integer backed enums on the docs page but does not filter them.
This is because the $value received by filterProperty is a string and not an integer.
I solved this by adding this short code snippet at the start of the normalizeValue function in the BackedEnumFilterTrait to attempt to convert the value to an integer if the enum is a backed integer enum.

        $firstCase = $this->enumTypes[$property]::cases()[0] ?? null;
        if (
            is_int($firstCase?->value)
            && false !== filter_var($value, FILTER_VALIDATE_INT)
        ) {
            $value = (int) $value;
        }

Alternatively, we could use ReflectionEnum::getBackingType(), but this avoids the reflection overhead.

Example Repo: https://github.com/MeronNagy/api-platform-integer-backed-enum

[MeronNagy]

I believe class-string to be more appropriate here, I can revert this if needed.

[soyuka]

would it be possible to add a test? can be a functional test (there should be some example in tests/Functional) or unit (src/Doctrine/Common/Tests) check CONTRIBUTING.md if you need more informations

[MeronNagy]

would it be possible to add a test? can be a functional test (there should be some example in tests/Functional) or unit (src/Doctrine/Common/Tests) check CONTRIBUTING.md if you need more informations

Yes sure I'll add one tomorrow!