attribute.interface

Code example

<?php declare(strict_types = 1);

#[\Attribute]
interface MyAttribute
{
	public function getValue(): string;
}

Why is it reported?

PHP requires attribute classes to be non-abstract classes. An interface cannot be used as an attribute class because PHP needs to instantiate the attribute when it is applied, and interfaces cannot be instantiated. Using #[\Attribute] on an interface is invalid and will cause a runtime error.

In the example above, MyAttribute is declared as an interface with the #[\Attribute] attribute, which is not allowed.

How to fix it

Change the interface to a class:

 <?php declare(strict_types = 1);

 #[\Attribute]
-interface MyAttribute
+class MyAttribute
 {
-	public function getValue(): string;
+	public function __construct(
+		public readonly string $value,
+	) {
+	}
 }