psalm-if-this-is crashes with enums

[thomasvargiu]

https://psalm.dev/r/7bed033139

Uncaught RuntimeException: PHP Error: Undefined array key 0 in ./vendor/vimeo/psalm/src/Psalm/Internal/Type/TemplateStandinTypeReplacer.php:1171

psalm/src/Psalm/Internal/Type/TemplateStandinTypeReplacer.php

Lines 1170 to 1174 in 0294324

	if (count($mapped_type_atomic_types) > 1
	|| !$mapped_type_atomic_types[0] instanceof TTemplateParam
	) {
	return $mapped_type;
	}

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/7bed033139

<?php

enum EnumA: string {
    case FOO = 'foo';
    case BAR = 'bar';
}

/**
 * @template T of EnumA
 */
class C {
    /**
     * @var T
     */
    private $data;
    /**
     * @param T $data
     */
    public function __construct($data) {
        $this->data = $data;
    }
    /**
     * @psalm-if-this-is self<EnumA::FOO>
     * 
     * @return void
     */
    public function doSomething() {
        /** @var self<EnumA::FOO> $this */
        $this->data = EnumA::FOO;
        // just somthing random to show psalm crashes 
        rgahatrhagfhaf
    }
}

Psalm output (using commit 16b24bd):

ERROR: ParseError - 32:5 - Syntax error, unexpected '}' on line 32

ERROR: UndefinedConstant - 31:9 - Const rgahatrhagfhaf is not defined

[thomasvargiu]

psalm-github-bot doesn't show the real output. Currently it crashes even in psalm.dev.