Error Identifier: parameter.notByRef
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);
interface Processor
{
public function process(string &$value): void;
}
class MyProcessor implements Processor
{
public function process(string $value): void
{
}
}
Why is it reported? #
A child class or implementation declares a parameter as not passed by reference, but the parent method or interface declares the corresponding parameter as passed by reference. This is a violation of the Liskov Substitution Principle.
This can also be reported when a @param-out PHPDoc tag is used on a parameter that is not passed by reference.
How to fix it #
Match the parent’s parameter passing convention:
<?php declare(strict_types = 1);
class MyProcessor implements Processor
{
- public function process(string $value): void
+ public function process(string &$value): void
{
}
}
How to ignore this error #
You can use the identifier parameter.notByRef to ignore this error using a comment:
// @phpstan-ignore parameter.notByRef
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: parameter.notByRef