Add test for the $hidden property

tests/Models/HiddenAnimal.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MongoDB\Laravel\Tests\Models;
+
+use MongoDB\Laravel\Eloquent\Model as Eloquent;
+use MongoDB\Laravel\Query\Builder;
+
+/**
+ * @property string $name
+ * @property string $country
+ * @property bool $can_be_eaten
+ * @mixin Eloquent
+ * @method static Builder create(...$values)
+ * @method static Builder truncate()
+ * @method static Eloquent sole(...$parameters)
+ */
+final class HiddenAnimal extends Eloquent
+{
+    protected $fillable = [
+        'name',
+        'country',
+        'can_be_eaten',
+    ];
+
+    protected $hidden = ['country'];
+}

tests/PropertyTest.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MongoDB\Laravel\Tests\Eloquent;
+
+use MongoDB\Laravel\Tests\Models\HiddenAnimal;
+use MongoDB\Laravel\Tests\TestCase;
+
+use function assert;
+
+final class PropertyTest extends TestCase
+{
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        HiddenAnimal::truncate();
+    }
+
+    public function testCanHideCertainProperties(): void
+    {
+        HiddenAnimal::create([
+            'name' => 'Sheep',
+            'country' => 'Ireland',
+            'can_be_eaten' => true,
+        ]);
+
+        $hiddenAnimal = HiddenAnimal::sole();
+        assert($hiddenAnimal instanceof HiddenAnimal);
+        self::assertSame('Ireland', $hiddenAnimal->country);
+        self::assertTrue($hiddenAnimal->can_be_eaten);
+
+        self::assertArrayHasKey('name', $hiddenAnimal->toArray());
+        self::assertArrayNotHasKey('country', $hiddenAnimal->toArray(), 'the country column should be hidden');
+        self::assertArrayHasKey('can_be_eaten', $hiddenAnimal->toArray());
+    }
+}