Fixing Bug #249

[gerpo]

Default values work with MapFrom.

The issue with assign null to type, was that the default value was ignored if the mapping was not present.
Now it will fall back to the default if the mapped property is not present.

[aidan-casey]

@gerpo - I think this is the right direction, especially by using the reflection property's getDefaultValue. A few quick notes:

• getDefaultValue returns null if one is not set, so the hasDefaultValue check is unnecessary.
• I don't believe the DataTransferObjectProperty class should set the value. Let's have a method called getDefaultValue return the default value, and use that in the DataTransferObject constructor instead of the current null.

Make sense?

[gerpo]

@aidan-casey
Sure, the points make absolutely sense. Committed the changes.

[spatie-bot]

Dear contributor,

because this pull request seems to be inactive for quite some time now, I've automatically closed it. If you feel this pull request deserves some attention from my human colleagues feel free to reopen it.

[stevebauman]

This should be re-opened 👍

[aidan-casey]

@gerpo - Can you modify this PR to use the default parameter for Arr::get() as opposed to the null coalescing operator? I'll release this patch once that is done.

[gerpo]

@gerpo - Can you modify this PR to use the default parameter for Arr::get() as opposed to the null coalescing operator? I'll release this patch once that is done.

Done :)

[aidan-casey]

Thank you, @gerpo. Apologies for the delay!

[joecampo]

This is awesome. I literally just ran into this today. Talk about good timing. Thanks @aidan-casey & @gerpo you're lifesavers. ❤️

[sebdesign]

I think this is introducing a new bug, or if it's intended, that's a breaking change.

Before this PR, properties that had a default value, would be assigned the default value if the argument was null.
This was because of the null coalescing operator.
If Arr::get($args, $property->name) was null, then $this->{$property->name} would return the default value.

Now with Arr::get($args, $property->name, $property->getDefaultValue()), If the $args array has a key named $property->name, it will return its value whether it's null or not. The $property->getDefaultValue() will only be returned when the $args array does NOT have this key.

The following test was green until this PR.

$data = [
    'title' => 'Hello world',
    'description' => null,
];

$dto = new class ($data) extends DataTransferObject {
    public string $title;

    public string $description = 'Test Text';
};

$this->assertEquals('Hello world', $dto->title);
$this->assertEquals('Test Text', $dto->description);

Now this test throws an error:

TypeError: Cannot assign null to property Spatie\DataTransferObject\DataTransferObject@anonymous::$description of type string

/vendor/spatie/data-transfer-object/src/Reflection/DataTransferObjectProperty.php:48
/vendor/spatie/data-transfer-object/src/DataTransferObject.php:29

[aidan-casey]

@sebdesign - Please see #282. The behavior you are describing was never intended, documented, or a supported feature. It is not a breaking change worthy of a major release because it was a bug that was fixed in this PR.

[pr4xx]

For me this introduced a new bug in my application. I have a base class which extends DataTransferObject. In the constructor, just before calling parent::__construct();, I set some default values which I cannot set just using the class properties (for example object instantiation). Prior to this update this worked:

class BaseDTO extends DataTransferObject
{
    public MyObject $myObject;
    
    public function __construct(...$args)
    {
        // set default
        $this->myObject = new MyObject();
        // call parent
        parent::__construct(...$args);
    }
}

Now this fails because when the parent constructor runs, it tries to set $myObject to null because it has no default value. Prior to this update it would have used the existing instance created from me.
What would be the correct way to assign complex default values prior to assigning data from json/array?