How to test against class-string<Foo> if the class might not exist yet?

[Hanmac]

How to test against class-string if the class might not exist yet?

from psalm.

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/32dcca1a1b

<?php

/**
 * @param class-string<Throwable> $class
 */
function expectException(string $class): string {return $class;}

class ConversionException extends Exception
{
}

/**
 * class InvalidType extends ConversionException {
    }
 */


expectException(ConversionException::class);
if (class_exists(InvalidType::class)) {
  expectException(InvalidType::class);
}

Psalm output (using commit 16b24bd):

ERROR: InvalidArgument - 20:19 - Argument 1 of expectException expects class-string<Throwable>, but InvalidType::class provided

https://psalm.dev/r/5a6e7e25e5

<?php

/**
 * @param class-string<Throwable> $class
 */
function expectException(string $class): string {return $class;}

class ConversionException extends Exception
{
}

/**
 * class InvalidType extends ConversionException {
    }
 */


expectException(ConversionException::class);
if (class_exists(InvalidType::class) && is_a(InvalidType::class, \Throwable::class, true)) {
   expectException(InvalidType::class);
}

Psalm output (using commit 16b24bd):

ERROR: UndefinedClass - 19:46 - Class, interface or enum named InvalidType does not exist

ERROR: UndefinedClass - 20:20 - Class, interface or enum named InvalidType does not exist

INFO: MixedArgument - 20:20 - Argument 1 of expectException cannot be mixed, expecting class-string<Throwable>

https://psalm.dev/r/8b557386cf

<?php

/**
 * @param class-string<Throwable> $class
 */
function expectException(string $class): string {return $class;}

class ConversionException extends Exception
{
}

/**
 * class InvalidType extends ConversionException {
    }
 */


expectException(ConversionException::class);
if (class_exists(InvalidType::class))
    if (is_a(InvalidType::class, \Throwable::class, true)) {
        expectException(InvalidType::class);
}

Psalm output (using commit 16b24bd):

ERROR: InvalidArgument - 21:25 - Argument 1 of expectException expects class-string<Throwable>, but InvalidType::class provided