Array keys using single quotes are narrowed differently than the same array key using double quotes

[PatrickRose]

Bug report

I've just run pint against our repository and was surprised by our PHPStan errors increasing.

This mainly turned out to be because we had a baseline for this pattern that existed in the codebase

if (isset($searchParams['key']) && $searchParams['key'] && is_array($searchParams['key'])) {
    if (count($searchParams['key']) > 0) {
        // do query things here
    }
}

PHPStan correctly infers that $searchParams['key'] must be a non-empty array because of the $searchParams['key'] in the if statement.

However, our error count raised because pint rationalised everything to using single quotes and it turns out that using single and double quotes treats the array keys differently. See the attached code snippet

Code snippet that reproduces the problem

https://phpstan.org/r/62bbf8b9-1d65-46d9-8211-7e3f132d2e86

Expected output

PHPStan should have errored on both single and double

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No response

[staabm]

PHPStan remembers types based on expressions in code. I think the problem is that our node-key is based on printing the expressions and therefore we cache 2 different types, while the expressions are equivalent.

https://phpstan.org/r/aa593be7-9340-4380-a313-dd5cf31035e2

I think we need some kind of normalization

[PatrickRose]

A thought occurs - I'm on my phone so I can't test it easily. Does phpstan treat "$key.value" differently than $key . '.value'