requireImplements.enum

Code example

<?php declare(strict_types = 1);

enum SomeEnum
{
    case Foo;
    case Bar;
}

/**
 * @phpstan-require-implements SomeEnum
 */
trait MyTrait {}

Why is it reported?

The @phpstan-require-implements PHPDoc tag can only reference interfaces. Enums are not interfaces and cannot be "implemented" by a class. When a trait uses @phpstan-require-implements, it declares that any class using the trait must implement the specified interface. An enum cannot serve this role because PHP does not allow classes to implement enums.

How to fix it

Replace the enum reference with an interface that the enum implements:

 <?php declare(strict_types = 1);

+interface SomeEnumInterface {}
+
+enum SomeEnum: string implements SomeEnumInterface
+{
+    case Foo = 'foo';
+    case Bar = 'bar';
+}
+
 /**
- * @phpstan-require-implements SomeEnum
+ * @phpstan-require-implements SomeEnumInterface
  */
 trait MyTrait {}

Or remove the @phpstan-require-implements tag if the constraint is not needed:

 <?php declare(strict_types = 1);

-/**
- * @phpstan-require-implements SomeEnum
- */
 trait MyTrait {}