Add checkbox page property

src/Pages/Properties/Checkbox.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace Notion\Pages\Properties;
+
+/**
+ * @psalm-type CheckboxJson = array{
+ *      id: string,
+ *      type: "checkbox",
+ *      checkbox: bool,
+ * }
+ */
+class Checkbox implements PropertyInterface
+{
+    private const TYPE = Property::TYPE_CHECKBOX;
+
+    private Property $property;
+
+    private bool $checked;
+
+    private function __construct(Property $property, bool $checked)
+    {
+        $this->property = $property;
+        $this->checked = $checked;
+    }
+
+    public static function create(bool $checked = false): self
+    {
+        $property = Property::create("", self::TYPE);
+
+        return new self($property, $checked);
+    }
+
+    public static function fromArray(array $array): self
+    {
+        /** @psalm-var CheckboxJson $array */
+
+        $property = Property::fromArray($array);
+
+        $checked = $array[self::TYPE];
+
+        return new self($property, $checked);
+    }
+
+    public function toArray(): array
+    {
+        $array = $this->property->toArray();
+
+        $array[self::TYPE] = $this->checked;
+
+        return $array;
+    }
+
+    public function property(): Property
+    {
+        return $this->property;
+    }
+
+    public function isChecked(): bool
+    {
+        return $this->checked;
+    }
+
+    public function check(): self
+    {
+        return new self($this->property, true);
+    }
+
+    public function uncheck(): self
+    {
+        return new self($this->property, false);
+    }
+}

src/Pages/Properties/Factory.php

@@ -22,6 +22,7 @@ public static function fromArray(array $array): PropertyInterface
             Property::TYPE_FORMULA => Formula::fromArray($array),
             Property::TYPE_RELATION => Relation::fromArray($array),
             Property::TYPE_PEOPLE => People::fromArray($array),
+            Property::TYPE_CHECKBOX => Checkbox::fromArray($array),
             default => throw new Exception("Invalid property type: '{$type}'"),
         };
     }

src/Pages/Properties/Property.php

@@ -126,10 +126,10 @@ public function isPeople(): bool
     //     return $this->type === self::TYPE_FILES;
     // }
 
-    // public function isCheckbox(): bool
-    // {
-    //     return $this->type === self::TYPE_CHECKBOX;
-    // }
+    public function isCheckbox(): bool
+    {
+        return $this->type === self::TYPE_CHECKBOX;
+    }
 
     // public function isUrl(): bool
     // {

tests/Unit/Pages/Properties/CheckboxTest.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace Notion\Test\Unit\Pages\Properties;
+
+use Notion\Pages\Properties\Checkbox;
+use Notion\Pages\Properties\Factory;
+use PHPUnit\Framework\TestCase;
+
+class CheckboxTest extends TestCase
+{
+    public function test_create(): void
+    {
+        $checkbox = Checkbox::create(true);
+
+        $this->assertTrue($checkbox->property()->isCheckbox());
+        $this->assertTrue($checkbox->isChecked());
+    }
+
+    public function test_check(): void
+    {
+        $checkbox = Checkbox::create()->check();
+
+        $this->assertTrue($checkbox->isChecked());
+    }
+
+    public function test_uncheck(): void
+    {
+        $checkbox = Checkbox::create(true)->uncheck();
+
+        $this->assertFalse($checkbox->isChecked());
+    }
+
+    public function test_array_conversion(): void
+    {
+        $array = [
+            "id" => "abc",
+            "type" => "checkbox",
+            "checkbox" => true,
+        ];
+
+        $checkbox = Checkbox::fromArray($array);
+        $fromFactory = Factory::fromArray($array);
+
+        $this->assertEquals($array, $checkbox->toArray());
+        $this->assertEquals($array, $fromFactory->toArray());
+    }
+}