InvalidArrayOffset reported for array_keys() keys

[ostrolucky]

https://psalm.dev/r/6c6ea1b229

OG issue at https://github.com/doctrine/DoctrineBundle/pull/1728/files#diff-afe5f060789287a8ad428a4b5df1ad844184f496ece0297e421f6b1fc442b5a4

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/6c6ea1b229

<?php

/** @param array<mixed> $config */
function foo (array $config): array {  
    $bar = [];
    foreach (array_keys($config['connections']) as $name) {
        $bar[$name] = 'hmm';
    }
    
    return $bar;
}

Psalm output (using commit 5095f4e):

INFO: PossiblyUndefinedStringArrayOffset - 6:25 - Possibly undefined array offset ''connections'' is risky given expected type 'array-key'. Consider using isset beforehand.

INFO: MixedArgument - 6:25 - Argument 1 of array_keys cannot be mixed, expecting array<array-key, mixed>

ERROR: InvalidArrayOffset - 7:9 - Cannot access value on variable $bar[$name] using a key-of<array<array-key, mixed>> offset, expecting array-key

[weirdan]

You need to validate that you pass an array to the array_keys(): https://psalm.dev/r/409ee9c8ec

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/409ee9c8ec

<?php

/** @param array<mixed> $config */
function foo (array $config): array {  
    $bar = [];
    if (!isset($config['connections']) || !is_array($config['connections'])) {
        throw new RuntimeException;
    }
    foreach (array_keys($config['connections']) as $name) {
        $bar[$name] = 'hmm';
    }
    
    return $bar;
}

Psalm output (using commit 3c90054):

No issues!