enumImplements.enum - Phpstan

Code example

php

<?php declare(strict_types = 1);

enum Color
{
	case Red;
}

enum Shape implements Color
{
	case Circle;
}

Why is it reported?

An enum uses implements to reference another enum instead of an interface. In PHP, enums can only implement interfaces. An enum cannot implement another enum.

How to fix it

If both enums need to share a common contract, create an interface:

diff-php

 <?php declare(strict_types = 1);

+interface HasLabel
+{
+	public function label(): string;
+}
+
-enum Color
+enum Color implements HasLabel
 {
 	case Red;
+
+	public function label(): string
+	{
+		return $this->name;
+	}
 }

-enum Shape implements Color
+enum Shape implements HasLabel
 {
 	case Circle;
+
+	public function label(): string
+	{
+		return $this->name;
+	}
 }