Add rich text database property

src/Databases/Properties/Factory.php

@@ -15,6 +15,7 @@ public static function fromArray(array $array): PropertyInterface
 
         return match($type) {
             Property::TYPE_TITLE => Title::fromArray($array),
+            Property::TYPE_RICH_TEXT => RichText::fromArray($array),
             default => throw new Exception("Invalid property type: '{$type}'"),
         };
     }

src/Databases/Properties/Property.php

@@ -80,10 +80,10 @@ public function type(): string
         return $this->type;
     }
 
-    // public function isRichText(): bool
-    // {
-    //     return $this->type === self::TYPE_RICH_TEXT;
-    // }
+    public function isRichText(): bool
+    {
+        return $this->type === self::TYPE_RICH_TEXT;
+    }
 
     // public function isNumber(): bool
     // {

src/Databases/Properties/RichText.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace Notion\Databases\Properties;
+
+/**
+ * @psalm-type RichTextJson = array{
+ *      id: string,
+ *      name: string,
+ *      type: "rich_text",
+ *      rich_text: array<empty, empty>,
+ * }
+ */
+class RichText implements PropertyInterface
+{
+    private const TYPE = Property::TYPE_RICH_TEXT;
+
+    private Property $property;
+
+    private function __construct(Property $property)
+    {
+        $this->property = $property;
+    }
+
+    public static function create(string $propertyName): self
+    {
+        $property = Property::create("", $propertyName, self::TYPE);
+
+        return new self($property);
+    }
+
+    public function property(): Property
+    {
+        return $this->property;
+    }
+
+    public static function fromArray(array $array): self
+    {
+        /** @psalm-var RichTextJson $array */
+        $property = Property::fromArray($array);
+
+        return new self($property);
+    }
+
+    public function toArray(): array
+    {
+        $array = $this->property->toArray();
+        $array[self::TYPE] = [];
+
+        return $array;
+    }
+}

tests/Unit/Databases/Properties/RichTextTest.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Notion\Test\Unit\Databases\Properties;
+
+use Notion\Databases\Properties\Factory;
+use Notion\Databases\Properties\RichText;
+use PHPUnit\Framework\TestCase;
+
+class RichTextTest extends TestCase
+{
+    public function test_create(): void
+    {
+        $text = RichText::create("Dummy prop name");
+
+        $this->assertEquals("Dummy prop name", $text->property()->name());
+        $this->assertTrue($text->property()->isRichText());
+    }
+
+    public function test_array_conversion(): void
+    {
+        $array = [
+            "id"    => "abc",
+            "name"  => "dummy",
+            "type"  => "rich_text",
+            "rich_text" => [],
+        ];
+        $text = RichText::fromArray($array);
+        $fromFactory = Factory::fromArray($array);
+
+        $this->assertEquals($array, $text->toArray());
+        $this->assertEquals($array, $fromFactory->toArray());
+    }
+}