Intersection types don't allow arrays

[danog]

I find it often useful to use intersection types to enhance the keys of an array, but psalm doesn't like it: https://psalm.dev/r/125b383b8b

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/125b383b8b

<?php

/**
 * @template T as array
 * @param T $i
 * @return T&array{test1: "test"}
 */
function enhance(array $i): array {
    $i['i'] = 'test';
    return $i;
}

Psalm output (using commit faad966):

ERROR: InvalidDocblock - 8:1 - Intersection types must be all objects, Psalm\Type\Atomic\TKeyedArray provided in docblock for enhance

[orklah]

This is just missing support for intersections between templates and keyed array. The intersection in itself is ok: https://psalm.dev/r/9384c60365

This should probably not be hard to fix and we have one or two similar issues (intersection with aliased types)

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/9384c60365

<?php

/**
 * @template T as array
 * @param T $i
 * @return array&array{test1: "test"}
 */
function enhance(array $i): array {
    $i['i'] = 'test';
    return $i;
}

Psalm output (using commit faad966):

ERROR: InvalidReturnStatement - 10:12 - The inferred type 'array{i: 'test'}' does not match the declared return type 'array{test1: 'test'}' for enhance

ERROR: InvalidReturnType - 6:12 - The declared return type 'array{test1: 'test'}' for enhance is incorrect, got 'array{i: 'test'}'

[kkmuffme]

Especially with v5 unsealed arrays and restrictReturnTypes this is a more common issue now

[kkmuffme]

It seems this worked previously? #3064