Arbitrary array combinations that correlate with the type key

[timuradilev]

In the example below depending on the type's value correct keys are queried.
https://psalm.dev/r/35b374c933
Is Psalm capable of learning that the code is correct? Are there any workarounds for the problem?

[orklah]

Currently, Psalm instantly collapse your notation into a single shape: https://psalm.dev/r/5ee0741dc3

I'm not sure what would happen if Psalm stopped doing that, it could be a good experiment if you're up for it. (It's done in TypeCombiner::combine)

[AndrolGenhald]

It's not currently possible because Union can only hold a single array with the "array" type key. This specifically is one of the reasons I started working on rewriting the type system, I'm not a fan of collapsing array{foo: "bar"}|array{bar: "baz"} to array{foo?: "bar", bar?: "baz"}.

[orklah]

Oh right, forgot about that too