instanceof.alwaysTrue

Code example

<?php declare(strict_types = 1);

function doFoo(\stdClass $obj): void
{
	if ($obj instanceof \stdClass) {
		// always entered
	}
}

Why is it reported?

The instanceof check always evaluates to true because the expression is already known to be of the checked type. In the example above, $obj is typed as \stdClass, so $obj instanceof \stdClass is always true. This makes the check redundant.

How to fix it

Remove the redundant instanceof check:

 <?php declare(strict_types = 1);

 function doFoo(\stdClass $obj): void
 {
-	if ($obj instanceof \stdClass) {
-		// always entered
-	}
+	// Execute the code unconditionally
 }