The type of keys used to index [] tables is not checked

[mycroftjr]

How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

Which OS are you using?

Windows

What is the issue affecting?

Type Checking

Expected Behaviour

Some warning should be raised if you use [5] on a table<string, x>, for example.

Actual Behaviour

In the expression tbl[x], the type of x is not checked at all

Reproduction steps

---@type table<integer, string> -- or string[]
local IntStr = {}
---@type table<string, integer>
local StrInt = {}
IntStr[5] = "hi" -- ok
IntStr["a"] = "b" -- "a" should produce a warning
StrInt["a"] = 5 -- ok
StrInt[5] = 6 -- 5 should produce a warning

Additional Notes

Probably related to #1861

Log File

No response

[emmericp]

+1 for supporting this, it is especially annoying if you have a table that is supposed to be indexed by an enum, e.g.,

---@type table<"foo"|"bar", number>
local foo

foo["wrong value"] = 5 -- should be an error