QueryResult:snapshot has untyped iter metamethod

[hazelmeow]

Currently it's typed as returning ReadonlyArray<[Entity<T>, ...T]>, but the return value actually has an __iter metamethod that interferes with things.

The metamethod lets you do this in Lua (the same as iterating a query without snapshotting it):

for entityId, health, player in world:query(Health, Player):snapshot() do

But in TS if we do something like .snapshot().mapFiltered(([id, health, player]) => {}), we'll generate something like:

local callback = function(_param)
    local id = _param[1]
    local cpn = _param[2]
    local player = _param[3]
end
-- ▼ ReadonlyArray.mapFiltered ▼
local _newValue = {}
local _length = 0
for _k, _v in querySnapshot do
    local _result = _arg0(_v, _k - 1, querySnapshot)
    if _result ~= nil then
        _length += 1
        _newValue[_length] = _result
    end
end
-- ▲ ReadonlyArray.mapFiltered ▲

And because of __iter, _k will end up being the id instead of the index and _v will be health, not [id, health, player], and so the callback will not get the value that the types think it will