property.notWritable

Code example

<?php declare(strict_types = 1);

interface HasValue
{
	public int $value { get; set; }
}

class Foo implements HasValue
{
	public int $value {
		get => 42;
	}
}

Why is it reported?

A child class overrides a writable property from a parent class or interface but makes it non-writable. In the example above, the interface HasValue declares $value as both readable and writable, but Foo only defines a get hook. Since the get hook does not reference the backing store, the property becomes virtual and has no set capability. This violates the writability contract established by the interface.

This rule applies to PHP 8.4+ property hooks.

How to fix it

Ensure the overriding property also supports writes:

 class Foo implements HasValue
 {
 	public int $value {
 		get => 42;
+		set => $value;
 	}
 }