String recognized as function instead of string

[parshikov]

The function someFunction accepts a parameter $callback with the type (callable(int):mixed)|string|null. However, when passing 'myFunc' (a name of almost any function) as an argument, a InvalidArgument error occurs.

https://psalm.dev/r/b0184be10a

Happened to me with PHP 8.3, Psalm 5.26.1, in Laravel Eloquent (v11).
I tried to aggregate metrics. count is the field of object with count of requests

/** @var Collection $statistics */
return $statistics->sum('count'); // InvalidArgument

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/b0184be10a

<?php

/**
 * Get the max value of a given key.
 *
 * @param  (callable(int):mixed)|string|null  $callback
 * @return mixed
 */
function someFunction(callable|string|null $callback): callable|string|null
{
    return $callback;
}

/**
 * @param array $value The array or the object.
 * @param int $mode [optional] If the optional mode parameter is set to
*/
function myFunc(array $value, int $mode = COUNT_NORMAL): int {
	return count($value)*$mode; //just to suppress UnusedParameter
}

someFunction('myFunc'); // <- this is valid parameter with type 'string' but InvalidArgument appeared, no ok
someFunction((string)'myFunc'); // <- no InvalidArgument

Psalm output (using commit 765dcbf):

ERROR: InvalidArgument - 22:14 - Argument 1 of someFunction expects callable(int):mixed|null|string, but impure-callable(array<array-key, mixed>, int=):int provided

ERROR: RedundantCast - 23:14 - Redundant cast to string