Error Identifier: conditionalType.alwaysFalse
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);
/**
* @return ($i is string ? non-empty-array : array)
*/
function fill(int $i): array
{
return [];
}
Why is it reported? #
The condition in a conditional return type PHPDoc tag can never be true. In the example above, $i is declared as int in the native type, so the condition $i is string is always false – an int value will never be a string. This makes the conditional return type pointless because only the “false” branch will ever apply, and it usually indicates an error in the PHPDoc annotation.
How to fix it #
Fix the condition to test a type that is actually possible for the parameter:
<?php declare(strict_types = 1);
/**
- * @return ($i is string ? non-empty-array : array)
+ * @return ($i is positive-int ? non-empty-array : array)
*/
function fill(int $i): array
{
return [];
}
Or widen the parameter type so the condition becomes meaningful:
<?php declare(strict_types = 1);
/**
* @return ($i is string ? non-empty-array : array)
*/
-function fill(int $i): array
+function fill(int|string $i): array
{
return [];
}
How to ignore this error #
You can use the identifier conditionalType.alwaysFalse to ignore this error using a comment:
// @phpstan-ignore conditionalType.alwaysFalse
codeThatProducesTheError();You can also use only the identifier key to ignore all errors of the same type in your configuration file in the ignoreErrors parameter:
parameters:
ignoreErrors:
-
identifier: conditionalType.alwaysFalse