method.visibility

Code example

<?php declare(strict_types = 1);

class Foo
{
	public function doFoo(): void
	{
	}
}

class Bar extends Foo
{
	private function doFoo(): void
	{
	}
}

Why is it reported?

An overriding method has a more restrictive visibility than the parent method. PHP enforces that overriding methods must not reduce visibility: a public method cannot be overridden with protected or private, and a protected method cannot be overridden with private.

This is a requirement of the Liskov Substitution Principle and is enforced by PHP at runtime with a fatal error.

How to fix it

Match or widen the visibility of the overriding method:

 <?php declare(strict_types = 1);

 class Bar extends Foo
 {
-	private function doFoo(): void
+	public function doFoo(): void
 	{
 	}
 }