ReflectionClass::newInstanceArgs() accepts associative arrays

[BenMorel]

Since PHP 8, ReflectionClass::newInstanceArgs() accepts an associative array of parameter names.

This code works (https://3v4l.org/L0kj4):

class X {
    public function __construct(
        string $a,
        string $b,
    ) {
        echo "\$a = $a\n";
        echo "\$b = $b\n";
    }
}

$r = new ReflectionClass(X::class);
$r->newInstanceArgs([
    'b' => 1,
    'a' => 2,
]);

But Psalm fails with:

ERROR: InvalidArgument - 14:21 - Argument 1 of ReflectionClass::newInstanceArgs expects array<int, mixed>, but array{a: 2, b: 1} provided

https://psalm.dev/r/835445aea1

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/835445aea1

<?php

class X {
    public function __construct(
        public readonly string $a,
        public readonly string $b,
    ) {
    }
}

$r = new ReflectionClass(X::class);
$r->newInstanceArgs([
    'b' => 1,
    'a' => 2,
]);

Psalm output (using commit 1350992):

ERROR: InvalidArgument - 12:21 - Argument 1 of ReflectionClass::newInstanceArgs expects array<int, mixed>, but array{a: 2, b: 1} provided

[BenMorel]

I tried to fix it, but I fail to understand the hierarchy of CallMaps that leads Psalm to fail on this example on PHP 8:

• CallMap.php has types that should work:

  'ReflectionClass::newInstanceArgs' => ['object', 'args='=>'array<array-key, mixed>'],
  'ReflectionObject::newInstanceArgs' => ['object', 'args='=>'array'],

• CallMap_historical.php has the old (i.e. pre- PHP 8) type, and a permissive type for ReflectionObject:

  'ReflectionClass::newInstanceArgs' => ['object', 'args='=>'list<mixed>'],
  'ReflectionObject::newInstanceArgs' => ['object', 'args='=>'array'],

• CallMap_80_delta.php has both the old and the new types correct:

  'ReflectionClass::newInstanceArgs' => [
    'old' => ['object', 'args='=>'list<mixed>'],
    'new' => ['object', 'args='=>'array<array-key, mixed>'],
  ],

---

I think a sane validation would be (for both ReflectionClass and ReflectionObject):

• PHP 7: list<mixed>
• PHP 8: list<mixed>|array<string, mixed>

(even though newInstanceArgs() also accepts arrays with out-of-order int keys, but ignores keys in this case).

[orklah]

@BenMorel new stubs were introduced for Reflection classes: https://github.com/vimeo/psalm/blob/master/stubs/Reflection.phpstub

They take precedence over the callmaps, your fix should belong here