Error Identifier: return.internalInterface

← Back to return.*

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);

namespace Vendor {
	/** @internal */
	interface InternalInterface {}

	class ConcreteClass implements InternalInterface {}
}

namespace App {
	function getHandler(): \Vendor\InternalInterface {
		return new \Vendor\ConcreteClass();
	}
}

Why is it reported? #

The return type of a function or method references an interface that is marked as @internal. Internal types are not part of the package’s public API and may change or be removed without notice. Exposing an internal interface in a return type creates a dependency on an implementation detail.

How to fix it #

Use a public (non-internal) type in the return type instead:

 namespace App {
-	function getHandler(): \Vendor\InternalInterface {
+	function getHandler(): \Vendor\PublicInterface {
 		return new \Vendor\ConcreteClass();
 	}
 }

If no public alternative exists, consider reaching out to the package maintainers to request a public API for your use case.

How to ignore this error #

You can use the identifier return.internalInterface to ignore this error using a comment:

// @phpstan-ignore return.internalInterface
codeThatProducesTheError();

You can also use only the identifier key to ignore all errors of the same type in your configuration file in the ignoreErrors parameter:

parameters:
	ignoreErrors:
		-
			identifier: return.internalInterface

Rules that report this error #

• PHPStan\Rules\InternalTag\RestrictedInternalClassNameUsageExtension [1]