scalar casters ignore nullability - empty string becomes 0/false instead of null

[laylatichy]

Tempest version

3.9

PHP version

8.5

Operating system

Windows, macOS

Description

when i have a request like this:

final class MyRequest implements Request {
    use IsRequest;

    public ?int $user_id = null;
    public ?float $price = null;
    public ?bool $featured = null;
}

and the form sends empty values (which browsers do when a field is cleared):

$request = map(['user_id' => '', 'price' => '', 'featured' => ''])
    ->to(MyRequest::class);

i expected $request->user_id to be null, $request->price to be null, etc - since the properties are nullable and the input is empty.

what actually happens

• $request->user_id is 0 (not null)
• $request->price is 0.0 (not null)
• $request->featured is false (not null)

the casters use intval(), floatval(), (bool) without checking if the property is nullable

// IntegerCaster
public function cast(mixed $input): int
{
    return intval($input); // intval("") === 0
}

// FloatCaster
public function cast(mixed $input): float
{
    return floatval($input); // floatval("") === 0.0
}

ArrayToObjectMapper::resolveValue() does check for null:

if ($property->isNullable() && $value === null) {
    return null;
}

but this is === null, so empty strings fall through to the casters.

i'm working around it with hooked property getters for now but it would be nice if plain nullable properties just worked.

i'll file a pr with a fix later if this makes sense.