Add dirname return type provider

[mcaskill]

Resolves #7344

Replaces #8609:

• Targets Psalm v5 (master)
• Fixes handling of call arguments
• Fixes unit tests

[orklah]

Seems great!

Two issues left to resolve, the Typeprovider should be marked @internal and a test broke due to your PR resolving the type more precisely, you can just replace the literal-string by the literal value

[mcaskill]

Two issues left to resolve, the Typeprovider should be marked @internal and a test broke due to your PR resolving the type more precisely, you can just replace the literal-string by the literal value

Thanks for the feedback. Both issues have now been resolved.

[orklah]

Thanks!

[kkmuffme]

@mcaskill could you do the same PR for basename too? (perhaps for str_replace too, since dir/basename and str_replace are the most common which would be extremely usable)

[mcaskill]

@kkmuffme I should be able to add basename easily. I might be able to also add realpath.

As for str_replace, that will be more complicated from what I've been able to learn from Psalm's codebase so far. There's currently a return type provider that handles str_replace, str_ireplace, substr_replace, preg_replace, and preg_replace_callback, which is a lot of different parameters to figure out how to resolve.

Just this morning, I realized the following use case does not work for dirname, which I'll need to figure out. I erroneously forgot and premused IncludeAnalyzer::getPathTo() would have been able to resolve the variable:

$path = "a/b/c";
$dir = dirname($path); // ← return type is evaluated as 'string' instead of literal string

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/1708b073c2

<?php

/** @psalm-trace $foo */
$foo = __DIR__;

/** @psalm-trace $baz */
$baz = dirname( $foo );

echo $baz;

Psalm output (using commit aea40ef):

INFO: Trace - 4:1 - $foo: '/var/www/vhosts/psalm.dev/httpdocs/src'

INFO: Trace - 7:1 - $baz: string

[kkmuffme]

@mcaskill I created a PR for the basename return type provider #8620 and one for the simplest case of str_(i)replace #8619 which covers what is most commonly used with dirname/basename paths, so that's done.

Feel free to create one for realpath though