argument.unpackNonIterable - Phpstan

Code example

php

<?php declare(strict_types = 1);

function doFoo(int $value): void
{
    sprintf('%s %s', ...$value);
}

Why is it reported?

The argument unpacking operator ... can only be used with iterable values (arrays or objects implementing Traversable). Attempting to unpack a non-iterable value like an int, string, or object that does not implement Traversable is a runtime error.

How to fix it

Pass an iterable value to the unpacking operator:

diff-php

 <?php declare(strict_types = 1);

-function doFoo(int $value): void
+function doFoo(array $values): void
 {
-    sprintf('%s %s', ...$value);
+    sprintf('%s %s', ...$values);
 }

Or pass the arguments directly without unpacking:

diff-php

 <?php declare(strict_types = 1);

 function doFoo(int $value): void
 {
-    sprintf('%s %s', ...$value);
+    sprintf('%s', $value);
 }