refactor: serialise and validate a configuration

...data object

src/ConfigurationData.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OliverDaviesLtd\BuildConfigs;
+
+use Symfony\Component\Validator\Constraints as Assert;
+
+final class ConfigurationData
+{
+    #[Assert\Collection(
+        allowExtraFields: false,
+        fields: [
+            'extra_databases' => new Assert\Optional(
+                new Assert\All(new Assert\Type('string'))
+            ),
+            'type' => new Assert\Choice(['mariadb', 'mysql']),
+            'version' => new Assert\Type('integer'),
+        ],
+        allowExtraFields: false,
+    )]
+    public array $database;
+
+    #[Assert\Choice(choices: ['node', 'php'])]
+    #[Assert\NotBlank]
+    public string $language;
+
+    #[Assert\Length(min: 1)]
+    #[Assert\NotBlank]
+    public string $name;
+
+    #[Assert\Choice(choices: ['drupal-project', 'fractal', 'laravel', 'php-library'])]
+    #[Assert\NotBlank]
+    public string $type;
+
+    #[Assert\NotBlank]
+    public ?string $projectRoot;
+}