Enum values as class strings

[vlakarados]

Basically here's working code sample:
https://psalm.dev/r/c71751d4fe

Also is it possible to create a hint for enum values to be all class-strings?:

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/c71751d4fe

<?php

class Cli { public function __construct() {} }
class Web { public function __construct() {} }

enum Loader: string
{
    case CLI = Cli::class;
    case WEB = Web::class;
}

/** @param class-string $s */
function factory(string $s): object
{
    return new $s;
}

$enum = Loader::CLI;
factory($enum->value);

Psalm output (using commit 653ad66):

INFO: MixedMethodCall - 15:12 - Cannot call constructor on an unknown class

ERROR: ArgumentTypeCoercion - 19:9 - Argument 1 of factory expects class-string, but parent type 'Cli' provided

[vlakarados]

Seems to be related
#8978

[orklah]

Seems like the structure that holds the value of a case was designed to only hold literals (ints or strings):

psalm/src/Psalm/Storage/EnumCaseStorage.php

Line 12 in 958d1ca

public $value;

That's fine in most cases because literals are pretty much the most precise type you could end up with... except for class-string (the literal Foo is less precise than Foo::class even if they're the same thing in the end.

So yeah, the value property here should be transformed into an Atomic (so it can handle any type from Psalm (as long as we only have one but it should be ok)

that should not be very hard given in most place, we're actually jumping hoops to extract the literal from an Atomic or the other way around

[weirdan]

Fixed in #10165 (master).