attribute.enum

Code example

<?php declare(strict_types = 1);

#[\Attribute]
enum Suit
{
	case Hearts;
	case Diamonds;
}

Why is it reported?

PHP attributes can only be applied to classes (not abstract). An enum cannot be used as an #[\Attribute] class because PHP requires attribute classes to be non-abstract, non-enum, non-interface, non-trait classes. Marking an enum with #[\Attribute] has no effect and would cause an error if the enum were ever used as an attribute on another declaration.

How to fix it

Convert the attribute to a regular class:

 <?php declare(strict_types = 1);

-#[\Attribute]
-enum Suit
+#[\Attribute]
+class Suit
 {
-	case Hearts;
-	case Diamonds;
+	public function __construct(
+		public readonly string $value,
+	) {
+	}
 }