[Feature request] Add a pseudo-type for custom require-like functions

[SkyyySi]

I think it would be useful to have something like a Require<T>-type. This type would take a literal string type T and evaluate as the same type that calling require(modname: T) would. This way, a wrapper around require could easily be built like this:

--- Require a module, throwing an error if it returned `true` (meaning that you
--- probably forgot to actually return something from it).
---@generic T : string
---@param module_name T
---@return Require<T> module -- <-- Note the use of `Require<T>`
local function checked_require(module_name)
    assert(type(module_name) == "string", "The `module_name` must be a string!")

    local module = require(module_name)

    assert(
        module ~= true,
        string.format(
            "Could not import module: `require(%q)` returned `true`!",
            module_name
        )
    )

    return module
end

--------------------------------------------------------------------------------

local socket = checked_require("socket")
local socket_require = require("socket")

assert(socket == socket_require)

The type-hint of require() could then be changed to the following:

---@generic T : string
---@param module_name T
---@return Require<T> module
function require(module_name) end

The language server already has a way to make global functions behave like require built-in, in the form of the "Lua.runtime.special" setting. This type would essentially do the same, except that it would be more powerful / broadly usable, since it could be applied to any variable. It would also be easier to use, since it's just another type in your code instead of something hiding in a config file.