Array keys not retained when using splat operator to define class constant

[trowski]

When using the splat operator to define a class constant, Psalm seems to resolve the resulting array as having integer keys instead of retaining the key type of the source array.

https://psalm.dev/r/32157859fc

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/32157859fc

<?php

class BaseClass {
    public const KEYS = [
        'hostname' => 'host',
        'pass' => 'password',
        'dbname' => 'db',
    ];
}

class ChildClass extends BaseClass {
    public const KEYS = [
        ...parent::KEYS,
        'ssl' => 'sslmode',
   	];
}

/**
 * @param array<non-empty-string, non-empty-string> $keyMap
 */
function example(array $keyMap): void
{
}

example(ChildClass::KEYS);

Psalm output (using commit 0e43c44):

INFO: UnusedParam - 21:24 - Param keyMap is never referenced in this method

ERROR: InvalidArgument - 25:9 - Argument 1 of example expects array<non-empty-string, non-empty-string>, but array{0: 'host', 1: 'password', 2: 'db', ssl: 'sslmode'} provided

ERROR: InvalidConstantAssignmentValue - 12:18 - ChildClass::KEYS with declared type array{0: 'host', 1: 'password', 2: 'db', ssl: 'sslmode'} cannot be assigned type array{dbname: 'db', hostname: 'host', pass: 'password', ssl: 'sslmode'}

INFO: InvalidClassConstantType - 12:18 - The type "array{0: 'host', 1: 'password', 2: 'db', ssl: 'sslmode'}" for ChildClass::KEYS does not satisfy the type "array{dbname: 'db', hostname: 'host', pass: 'password'}" inherited from BaseClass::KEYS