@function annotation for class prototype members

[hinell]

How are you using the lua-language-server?

NeoVim

Which OS are you using?

Linux

What is the issue affecting?

Annotations

Expected Behaviour

Note

This is not a bug, but a feature request

--- $HOME/.local/nvim/lua/Clipboard.lua

--- Return size of the clipboard (max 1)
--- @return number size of the clipboard
function M.Clipboard.prototype:size()
  return #self
end

-- Instantiate
local cb = M.Clipboard:new() 
print(cb:size())
--       ^^^^^^^
-- LLS doesn't recognize :size() as method of an instance currently
-- there is no way to declare there is such

Consider an example above. Currently, there is no way to tell LLS to recognize prototype based class method as actual instance method. I request LLS to provide support for this field automatically or preferrably via ability to declare @function type with params description.

Design consideration: in JSDoc for instance, there is @public tag, see: google-closure-compiler @public

Workaround

Currently, it's possible to workaround the issue temporarily by

--- Clipboard instance
--- @class M.ClipboardInstance 
--- @field print fun(self): nil
--- @field size fun(self): number

--- @class M.Clipboard
--- @return M.ClipboardInstance
function M.Clipboard:new ()
-- ...
end

[Frityet]

Lua doesn't have prototype built in like that, the equivalent being __index, so I don't see why or how it would be implemented

[hinell]

@Frityet We just need annotation like @function to be able to fully specify types of functions. That would be enough. Currently we are limited to @field fun(x, y, z): ...

[Frityet]

@Frityet We just need annotation like @function to be able to fully specify types of functions. That would be enough. Currently we are limited to @field fun(x, y, z): ...

How would function be any different to

---@type fun(c: T): R
local function f(c) end

[hinell]

@Frityet We need to be able to define custom function types with full description of their params. fun(...): ... doesn't allow that. E.g.:

--- @function myCustomFnType
--- @param xyz string my param
--- @param bar number[]|nil optional param


--- @type myCustomFnType
local _wtf = nil

_wtf("is going on?", { 99, 88 }) -- no error by LLS

[carsakiller]

Adding a @function annotation is the conclusion we last came to in #1456. Your use case is slightly different from #1456's original problem, but they need the same solution.

[hinell]

Closing as duplicate #1456