From 365b3447f58c017a595ed6b52c3ba37290ab2f1b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Samuel=20=C5=A0tancl?= <samuel@archte.ch>
Date: Fri, 12 Jan 2024 22:35:58 +0100
Subject: [PATCH] Support defining #[Meta] on traits (resolve #9)

---
 src/Meta/Reflection.php  | 21 ++++++++++++++++-----
 tests/Pest/TraitTest.php | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+), 5 deletions(-)
 create mode 100644 tests/Pest/TraitTest.php

diff --git a/src/Meta/Reflection.php b/src/Meta/Reflection.php
index 68799d0..1e585af 100644
--- a/src/Meta/Reflection.php
+++ b/src/Meta/Reflection.php
@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace ArchTech\Enums\Meta;
 
 use ReflectionAttribute;
+use ReflectionClass;
 use ReflectionEnumUnitCase;
 use ReflectionObject;
 
@@ -19,12 +20,22 @@ class Reflection
     public static function metaProperties(mixed $enum): array
     {
         $reflection = new ReflectionObject($enum);
+        $metaProperties = static::parseMetaProperties($reflection);
 
-        // Attributes of the `Meta` type
-        $attributes = array_values(array_filter(
-            $reflection->getAttributes(),
-            fn (ReflectionAttribute $attr) => $attr->getName() === Meta::class,
-        ));
+        // Traits except the `Metadata` trait
+        $traits = array_values(array_filter($reflection->getTraits(), fn (ReflectionClass $class) => $class->getName() !== 'ArchTech\Enums\Metadata'));
+
+        foreach ($traits as $trait) {
+            $metaProperties = array_merge($metaProperties, static::parseMetaProperties($trait));
+        }
+
+        return $metaProperties;
+    }
+
+    protected static function parseMetaProperties(ReflectionClass $reflection): array
+    {
+        // Only the `Meta` attribute
+        $attributes = $reflection->getAttributes(Meta::class);
 
         if ($attributes) {
             /** @var Meta $meta */
diff --git a/tests/Pest/TraitTest.php b/tests/Pest/TraitTest.php
new file mode 100644
index 0000000..43730aa
--- /dev/null
+++ b/tests/Pest/TraitTest.php
@@ -0,0 +1,37 @@
+<?php
+
+use ArchTech\Enums\Meta\Meta;
+use ArchTech\Enums\Meta\MetaProperty;
+use ArchTech\Enums\Metadata;
+
+test('enums can use traits which define meta properties on themselves', function () {
+    expect(MyEnum::FOO->description())->toBe('Foo!');
+    expect(MyEnum::BAR->description())->toBe('Bar!');
+    expect(MyEnum::BAZ->description())->toBe(null);
+});
+
+enum MyEnum
+{
+    use Metadata;
+    use HasDescription;
+
+    #[Description('Foo!')]
+    case FOO;
+
+    #[Description('Bar!')]
+    case BAR;
+
+    case BAZ;
+}
+
+#[Attribute]
+class Description extends MetaProperty
+{}
+
+/**
+ * @method string|null description()
+ */
+#[Meta(Description::class)]
+trait HasDescription
+{
+}