str_pad, str_repeat and non-empty-strings

[ciaranmcnulty]

Psalm does not know that str_pad is guaranteed to return a non-empty-string for certain inputs

https://psalm.dev/r/c7f5c10980

If the input is a non-empty-string and the padding is >0, this should always be the case

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/c7f5c10980

<?php

/**
 * @param non-empty-string $foo
 */
function foo($foo) : void
{
	echo $foo;
}

foo(str_pad('a', 100));

Psalm output (using commit bee4e83):

ERROR: ArgumentTypeCoercion - 11:5 - Argument 1 of foo expects non-empty-string, parent type string provided

[weirdan]

If the input is a non-empty-string and the padding is >0, this should always be the case

Actually it's or, not and

[weirdan]

@ciaranmcnulty does the following signature match your expectations: https://psalm.dev/r/ecdcca18ba ?

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/ecdcca18ba

<?php
/**
 * @return ($_string is non-empty-string ? non-empty-string : ($_length is positive-int ? non-empty-string: string))
 */
function f(string $_string, int $_length): string {
  return $_string; // to suppress the error
}

$_a = f("a", 0); /** @psalm-trace $_a */; // expected: non-empty-string 
$_b = f("", 1); /** @psalm-trace $_b */; // expected: non-empty-string
$_c = f("", -1); /** @psalm-trace $_c */; // expected: string

Psalm output (using commit bee4e83):

INFO: Trace - 9:41 - $_a: non-empty-string

INFO: Trace - 10:40 - $_b: non-empty-string

INFO: Trace - 11:41 - $_c: string

[ciaranmcnulty]

It looks like there is some funny stuff when the length is less than the original string length too

[weirdan]

Got an example?

[ciaranmcnulty]

Actually that looks fine. There's a third param but it doesn't affect the logic as it has to be a non-empty-string.

str_repeat seems to have a very similar issue / solution