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);
#[\NoDiscard]
function pureCompute(int $x): int
{
return $x * 2;
}
$fn = Closure::fromCallable('pureCompute');
$fn(5);
Why is it reported? #
The callable is invoked on a separate line and its return value is discarded. The underlying function is marked with #[\NoDiscard] (PHP 8.5+), which indicates its return value must be used. Calling it without using the result means the call has no meaningful effect.
This error is not ignorable.
How to fix it #
Use the return value of the callable:
$fn = Closure::fromCallable('pureCompute');
-$fn(5);
+$result = $fn(5);
Non-ignorable error #
This error cannot be ignored using @phpstan-ignore or the ignoreErrors configuration. Non-ignorable errors indicate code that would cause a crash or a fatal error at runtime, or a fundamental problem in the analysed code that must be addressed.
Rules that report this error #
- PHPStan\Rules\Functions\CallToFunctionStatementWithNoDiscardRule [1]