logicalAnd.leftNotBoolean

Code example

<?php declare(strict_types = 1);

function doFoo(string $s, bool $b): void
{
	$result = $s and $b;
}

Why is it reported?

This error comes from phpstan-strict-rules. It reports that the left side of an and operator is not a boolean value. Strict boolean comparisons require both sides to be of type bool to avoid subtle bugs caused by PHP's type juggling. In the example, $s is a string, which will be implicitly coerced to bool.

How to fix it

Explicitly convert the value to a boolean:

 function doFoo(string $s, bool $b): void
 {
-	$result = $s and $b;
+	$result = ($s !== '') and $b;
 }

Or use a boolean variable:

-function doFoo(string $s, bool $b): void
+function doFoo(bool $a, bool $b): void
 {
-	$result = $s and $b;
+	$result = $a and $b;
 }