UnsafeForeachArrayOfStringRule doesn't report BenevolentUnionType of (int|string) (the default for unspecified array keys)

[dktapps]

Issue description

BenevolentUnionType is a very annoying PHPStan feature that suppresses errors when the union is passed to a type that only accepts a subset of its subtypes.

e.g.:

• int|string is accepted by int|string but not by int and not by string
• (int|string) is accepted by int|string, int, and string

This is a problem because (int|string) is the default array key type when doing @var SomeType[], meaning that dozens of potential crash points haven't been reported.

This is because UnsafeForeachArrayOfStringRule doesn't distinguish between explicit types and implicit ones.

Annoyingly, the places where BenevolentUnionType has suppressed these errors are the exact places we'd be most concerned about crashes.

OS and versions

• PocketMine-MP: 5.21.1

Crashdump, backtrace or other files

The following is a list of errors that pop up when UnsafeForeachArrayOfStringRule is modified to account for BenevolentUnionType. Unfortunately, many of these are quite annoying to fix, because Utils::stringifyKeys() can't infer types from BenevolentUnionType. @var is also difficult to use in many such cases as is_array() may overwrite info from @var.

output.txt