class.extendsFinal

Code example

<?php declare(strict_types = 1);

final class ParentClass
{

}

class ChildClass extends ParentClass // reported
{

}

Why is it reported?

A class declared as final cannot be extended. The final keyword explicitly prevents inheritance. Attempting to extend a final class results in a fatal error at runtime.

How to fix it

Either remove the final keyword from the parent class if inheritance is intended, or stop extending it and use composition instead.

Using composition:

-class ChildClass extends ParentClass
+class ChildClass
 {
+    public function __construct(
+        private ParentClass $parent,
+    ) {
+    }
 }

Or, if you control the parent class and inheritance is appropriate:

-final class ParentClass
+class ParentClass
 {

 }