Error Identifier: interfaceExtends.enum
Every error reported by PHPStan has an error identifier. Here’s a list of all error identifiers. In PHPStan Pro you can see the error identifier next to each error and filter errors by their identifiers.
Code example #
<?php declare(strict_types = 1);
enum Status
{
case Active;
case Inactive;
}
interface StatusInterface extends Status // ERROR: Interface StatusInterface extends enum Status.
{
}
Why is it reported? #
An interface cannot extend an enum in PHP. Interfaces can only extend other interfaces. Enums are a distinct type in PHP and cannot be used as a parent type for interfaces. This is a language-level constraint that will cause a fatal error at runtime.
How to fix it #
If the enum implements an interface, extend that interface instead:
<?php declare(strict_types = 1);
+interface HasLabelInterface
+{
+ public function label(): string;
+}
+
enum Status implements HasLabelInterface
{
case Active;
case Inactive;
public function label(): string
{
return $this->name;
}
}
-interface StatusInterface extends Status
+interface StatusInterface extends HasLabelInterface
{
}
If the intent is to type-hint against the enum, use the enum name directly as a type:
<?php declare(strict_types = 1);
function processStatus(Status $status): void
{
// ...
}
Non-ignorable error #
This error cannot be ignored using @phpstan-ignore or the ignoreErrors configuration. Non-ignorable errors indicate code that would cause a crash or a fatal error at runtime, or a fundamental problem in the analysed code that must be addressed.
Rules that report this error #
- PHPStan\Rules\Classes\ExistingClassesInInterfaceExtendsRule [1]