LuaLS / LuaLS/lua-language-server

Incorrect types used for overloaded class when passed as argument

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Lua
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Description

How are you using the lua-language-server?

NeoVim

Which OS are you using?

Linux

What is the issue affecting?

Type Checking

Expected Behaviour

When a class which is overloaded as a function, if that class is passed as an argument to another function it should be checked as if it is a function if the argument has a function type.

---@param f function
local function call(f) f() end

---@class foo
---@overload fun()
local something = setmetatable({}, {__call = function () end})

call(something) -- <-- Here something should be treated as `fun()`
Actual Behaviour

The type of the class is treated as foo|fun() which results in a warning because foo does not match function.

Reproduction steps
  1. Create a class with an overload
  2. Pass it to another function which takes a function argument
  3. Observe that a warning is produced
Additional Notes

No response

Log File

No response

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the supplied Lua reproduction and trace the type-checking path for function arguments and overloaded classes. Done means the example no longer warns when the callable class is passed to a function-typed parameter, while the reproduction steps continue to behave correctly.

Written by the indexing model from the issue text.

Assessment

Tech stack
lua
Domain
devtools
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
42/100

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