Bug report

When assigning values to a nested array within a typed array, since 2.1.12 the nested array type transitions from array{} to *NEVER* to mixed as values are assigned and then reports an offsetAccess.nonOffsetAccessible error.

The issue appears to be triggered by the type annotation on the parent array @var array<string, mixed>, removing the annotation makes the issue disappear.

Code snippet that reproduces the problem

https://phpstan.org/r/2894f0cc-6c77-48bf-952c-5aa5677c6913

Expected output

• PHPStan should maintain the array type information through the assignments
• The type should be something like array<string, int> after the assignments
• Subsequent array access should be valid

Actual behaviour

1. Initial empty array is correctly typed as array{}
2. After first assignment, type becomes *NEVER*
3. After second assignment, type becomes mixed

Did PHPStan help you today? Did it make you happy in any way?

Yes, it catches refactoring errors all time I couldn't ship as safely without it.