Error Identifier: class.extendsFinal
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);
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
{
}
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\ExistingClassInClassExtendsRule [1]