[Discusion/Proposal] MassAssignableException only thrown on first non mass assignable property, not on subsequent ones, behaviour proposal

[PrinsFrank]

Description:

When filling the property $fillable for a model and mass assigning values not in that array, those get quietly ignored, where mass assigning for the first time trows an exception. This is counter intuitive, because when mass assigning a new property I would expect an exception warning me that that property is not fillable instead of quietly continueing.

Steps To Reproduce:

<?php
declare(strict_types=1);

use Illuminate\Database\Eloquent\MassAssignmentException;
use Illuminate\Database\Eloquent\Model;
use PHPUnit\Framework\TestCase;

class ModelNotFillable extends Model
{
	protected $fillable = [];
}

class ModelOnePropertyFillable extends Model
{
	protected $fillable = [
		'foo'
	];
}

class ModelTest extends TestCase
{
	public function testModelNotFillable(): void
	{
		$this->expectException(MassAssignmentException::class);
		$this->expectExceptionMessage('Add [foo] to fillable property to allow mass assignment on [ModelNotFillable]');
		new ModelNotFillable(['foo' => 'bar', 'bar' => 'foo']);
	}

	public function testModelOnePropertyFillable(): void
	{

=====>  // I would Expect a MassAssignmentException here as well for the "bar" property

		$model = new ModelOnePropertyFillable(['foo' => 'bar', 'bar' => 'foo']);
		static::assertSame(['foo' => 'bar'], $model->getAttributes());
	}
}

Cause

In Illuminate/Database/Eloquent/Model.php in the 'fill' method, this behaviour is explicitely described:

// The developers may choose to place some attributes in the "fillable" array
// which means only those attributes may be set through mass assignment to
// the model, and all others will just get ignored for security reasons.

Proposal

This behaviour is counter intuitive. Is there a possibility to discuss changing this to always throw a massAssignableException when passing properties that are not set in the $fillable property? This would be a change for a major version, but I suspect there are lot more people that have bugs caused by this than there are people relying on the security feature aspect of this behavior.