consistentConstructor.private

Code example

<?php declare(strict_types = 1);

/** @phpstan-consistent-constructor */
class Foo
{
	private function __construct()
	{
	}
}

Why is it reported?

The @phpstan-consistent-constructor PHPDoc tag tells PHPStan to enforce that all child classes maintain a compatible constructor signature with the parent class. However, a private constructor cannot be overridden by child classes at all -- it prevents inheritance of the constructor entirely. Marking a private constructor as consistent is contradictory because child classes cannot call or match the parent constructor.

If the class is also final, this error is not reported because final classes cannot have child classes.

How to fix it

Change the constructor visibility to protected or public so child classes can inherit and override it:

 <?php declare(strict_types = 1);

 /** @phpstan-consistent-constructor */
 class Foo
 {
-	private function __construct()
+	protected function __construct()
 	{
 	}
 }

Alternatively, if the class is not meant to be extended, make it final and remove the @phpstan-consistent-constructor tag:

 <?php declare(strict_types = 1);

-/** @phpstan-consistent-constructor */
-class Foo
+final class Foo
 {
 	private function __construct()
 	{
 	}
 }