Stack overflow while attempting to resolve function return value #3246
Description
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
It is expected that the return value (callback) is resolved to Callback<string> which is expanded to fun(): Success, string where Success is fun(): Success (returns itself) without causing a stack overflow.
Actual Behaviour
A stack overflow occurs and the return value has an unknown type.
Reproduction steps
- Copy the following code into a lua file.
--- @alias Success fun(): Success
--- @alias Callback<T> fun(): Success, T
--- @return Success
local function success()
return success
end
--- @generic T
--- @param callback Callback<T>
--- @return Callback<T>
local function make_callback(callback)
return callback
end
local callback = make_callback(function()
return success, ""
end)- No special vscode settings or luarc file is required.
- Upon workspace reload or diagonistics, a stack overflow immediately occurs. Visible via view->output->Lua
Additional Notes
This is an abstract minimum reproduction of the issue. My full use case has multiple self returning functions used to indicate different statuses, and the make_callback function would be a method on a class instance to which the callbacks are registered to.