property.neverWritten - Phpstan

Code example

php

<?php declare(strict_types = 1);

class Queue
{
	private int $anotherProp;

	// Writable property Queue::$count is never written.
	private int $count {
		set {
			$this->anotherProp = $value;
		}
	}

	public function getCount(): int
	{
		return $this->count;
	}
}

Why is it reported?

The property is declared as writable-only (because it's a hooked set-only virtual property), but it is never actually written to anywhere in the code. This suggests the property is unused or the write operations are missing. A writable property that is never written serves no purpose.

PHPStan reports this as part of its dead code detection. Unused properties add unnecessary complexity and can indicate incomplete implementations.

How to fix it

If the property should be written, add the missing write operations:

diff-php

 	private int $count {
		set {
			$this->anotherProp = $value;
		}
	}

+	public function increment(): void
+	{
+		$this->count++;
+	}
+
 	public function getCount(): int
 	{
 		return $this->count;
 	}
 }

If the property is no longer needed, remove it:

diff-php

 	private int $anotherProp;
 	
-	private int $count {
-		set {
-			$this->anotherProp = $value;
-		}
-	}
-
-	public function getCount(): int
-	{
-		return $this->count;
-	}
 }