Type guards override assignments?

[davidgiven]

Here's a thing which surprised me:

local something: {[string]: string}? = nil
...
if not something then
    something = {}
    something["a"] = "b"
end

This fails with Expected type table, got 'nil' instead for the something dereference.

I'm guessing that the not something typeguard is telling the typechecker that something must be nil, but then the assignment is not overriding this (which means telling it that something cannot be nil).

Is there a way around this?

[davidgiven]

These do the same thing:

something = something or {}
something = if something then something else {}

[JohnnyMorganz]

Yeah, I think this is a known issue: #535